diff --git a/build.sbt b/build.sbt
index 0cd314c9..8227cd8d 100644
--- a/build.sbt
+++ b/build.sbt
@@ -80,26 +80,6 @@ val generateTupleCombinatorsTo = 9
 
 Compile / sourceGenerators += Def.task {
   Seq.concat(
-    GenerateCombineStreams(
-      (Compile / sourceDirectory).value,
-      from = generateTupleCombinatorsFrom,
-      to = generateTupleCombinatorsTo
-    ).run,
-    GenerateCombineSignals(
-      (Compile / sourceDirectory).value,
-      from = generateTupleCombinatorsFrom,
-      to = generateTupleCombinatorsTo
-    ).run,
-    GenerateSampleCombineStreams(
-      (Compile / sourceDirectory).value,
-      from = generateTupleCombinatorsFrom,
-      to = generateTupleCombinatorsTo
-    ).run,
-    GenerateSampleCombineSignals(
-      (Compile / sourceDirectory).value,
-      from = generateTupleCombinatorsFrom,
-      to = generateTupleCombinatorsTo
-    ).run,
     GenerateTupleStreams(
       (Compile / sourceDirectory).value,
       from = generateTupleCombinatorsFrom,
diff --git a/project/GenerateCombinableSignal.scala b/project/GenerateCombinableSignal.scala
index 317bb18f..154b465f 100644
--- a/project/GenerateCombinableSignal.scala
+++ b/project/GenerateCombinableSignal.scala
@@ -14,8 +14,10 @@ case class GenerateCombinableSignal(
     line("package com.raquo.airstream.combine.generated")
     line()
     line("import app.tulz.tuplez.Composition")
+    line("import com.raquo.airstream.combine.SampleCombineSignalN")
     line("import com.raquo.airstream.core.Signal")
     line("import com.raquo.airstream.core.Source.SignalSource")
+    line("import com.raquo.ew.JsArray")
     line()
     line("// #Warning do not edit this file directly, it is generated by GenerateCombinableSignal.scala")
     line()
@@ -40,22 +42,29 @@ case class GenerateCombinableSignal(
           line(s"combinator: (A, ${tupleType(n)}) => Out")
         }
         enter(s"): Signal[Out] = {", "}") {
-          line(s"new CombineSignal${n + 1}(signal, ${tupleType(n, "s")}, combinator)")
+          line(s"StaticSignalCombineOps.combineWithFn(signal, ${tupleType(n, "s")})(combinator)")
         }
         line()
         enter(s"def withCurrentValueOf[${tupleType(n)}](") {
           line((1 to n).map(i => s"s${i}: SignalSource[T${i}]").mkString(", "))
         }
         enter(s")(implicit c: Composition[A, (${tupleType(n)})]): Signal[c.Composed] = {", "}") {
-          line(s"val combinator = (a: A, ${(1 to n).map(i => s"v${i}: T${i}").mkString(", ")}) => c.compose(a, (${tupleType(n, "v")}))")
-          line(s"new SampleCombineSignal${n + 1}(signal, ${tupleType(n, "s")}, combinator)")
+          line(s"val combinator = (arr: JsArray[Any]) => c.compose(arr(0).asInstanceOf[A], (${(1 to n).map(i => s"arr(${i}).asInstanceOf[T${i}]").mkString(", ")}))")
+          line(s"val sampledSignals = JsArray[Signal[Any]](${tupleType(n, "s", ".toObservable")})")
+          enter(s"new SampleCombineSignalN(", ")") {
+            line("signal, sampledSignals, combinator")
+          }
         }
         line()
         enter(s"def sample[${tupleType(n)}](") {
           line((1 to n).map(i => s"s${i}: SignalSource[T${i}]").mkString(", "))
         }
         enter(s"): Signal[(${tupleType(n)})] = {", "}") {
-          line(s"new SampleCombineSignal${n + 1}[A, ${tupleType(n)}, (${tupleType(n)})](signal, ${tupleType(n, "s")}, (_, ${tupleType(n, "v")}) => (${tupleType(n, "v")}))")
+          line(s"val combinator = (arr: JsArray[Any]) => (${(1 to n).map(i => s"arr(${i}).asInstanceOf[T${i}]").mkString(", ")})")
+          line(s"val sampledSignals = JsArray[Signal[Any]](${tupleType(n, "s", ".toObservable")})")
+          enter(s"new SampleCombineSignalN[Any, (${tupleType(n)})](", ")") {
+            line("signal, sampledSignals, combinator")
+          }
         }
         line()
         line("// --")
diff --git a/project/GenerateCombinableStream.scala b/project/GenerateCombinableStream.scala
index e3e76537..9ed77a6d 100644
--- a/project/GenerateCombinableStream.scala
+++ b/project/GenerateCombinableStream.scala
@@ -14,8 +14,10 @@ case class GenerateCombinableStream(
     line("package com.raquo.airstream.combine.generated")
     line()
     line("import app.tulz.tuplez.Composition")
-    line("import com.raquo.airstream.core.EventStream")
+    line("import com.raquo.airstream.combine.SampleCombineStreamN")
+    line("import com.raquo.airstream.core.{EventStream, Signal}")
     line("import com.raquo.airstream.core.Source.{EventSource, SignalSource}")
+    line("import com.raquo.ew.JsArray")
     line()
     line("// #Warning do not edit this file directly, it is generated by GenerateCombinableStream.scala")
     line()
@@ -40,22 +42,29 @@ case class GenerateCombinableStream(
           line(s"combinator: (A, ${tupleType(n)}) => Out")
         }
         enter(s"): EventStream[Out] = {", "}") {
-          line(s"new CombineStream${n + 1}(stream, ${tupleType(n, "s")}, combinator)")
+          line(s"StaticStreamCombineOps.combineWithFn(stream, ${tupleType(n, "s")})(combinator)")
         }
         line()
         enter(s"def withCurrentValueOf[${tupleType(n)}](") {
           line((1 to n).map(i => s"s${i}: SignalSource[T${i}]").mkString(", "))
         }
         enter(s")(implicit c: Composition[A, (${tupleType(n)})]): EventStream[c.Composed] = {", "}") {
-          line(s"val combinator = (a: A, ${(1 to n).map(i => s"v${i}: T${i}").mkString(", ")}) => c.compose(a, (${tupleType(n, "v")}))")
-          line(s"new SampleCombineStream${n + 1}(stream, ${tupleType(n, "s")}, combinator)")
+          line(s"val combinator = (arr: JsArray[Any]) => c.compose(arr(0).asInstanceOf[A], (${(1 to n).map(i => s"arr(${i}).asInstanceOf[T${i}]").mkString(", ")}))")
+          line(s"val sampledSignals = JsArray[Signal[Any]](${tupleType(n, "s", ".toObservable")})")
+          enter(s"new SampleCombineStreamN(", ")") {
+            line("stream, sampledSignals, combinator")
+          }
         }
         line()
         enter(s"def sample[${tupleType(n)}](") {
           line((1 to n).map(i => s"s${i}: SignalSource[T${i}]").mkString(", "))
         }
         enter(s"): EventStream[(${tupleType(n)})] = {", "}") {
-          line(s"new SampleCombineStream${n + 1}[A, ${tupleType(n)}, (${tupleType(n)})](stream, ${tupleType(n, "s")}, (_, ${tupleType(n, "v")}) => (${tupleType(n, "v")}))")
+          line(s"val combinator = (arr: JsArray[Any]) => (${(1 to n).map(i => s"arr(${i}).asInstanceOf[T${i}]").mkString(", ")})")
+          line(s"val sampledSignals = JsArray[Signal[Any]](${tupleType(n, "s", ".toObservable")})")
+          enter(s"new SampleCombineStreamN[Any, (${tupleType(n)})](", ")") {
+            line("stream, sampledSignals, combinator")
+          }
         }
         line()
         line("// --")
diff --git a/project/GenerateCombineSignals.scala b/project/GenerateCombineSignals.scala
deleted file mode 100644
index b1ea7673..00000000
--- a/project/GenerateCombineSignals.scala
+++ /dev/null
@@ -1,44 +0,0 @@
-import sbt._
-
-import java.io.File
-
-case class GenerateCombineSignals(
-  sourceDir: File,
-  from: Int,
-  to: Int
-) extends SourceGenerator(
-  sourceDir / "scala" / "com" / "raquo" / "airstream" / "combine" / "generated" / s"CombineSignals.scala"
-) {
-
-  override def apply(): Unit = {
-    line("package com.raquo.airstream.combine.generated")
-    line()
-    line("import com.raquo.airstream.combine.CombineSignalN")
-    line("import com.raquo.airstream.core.Source.SignalSource")
-    line()
-    line("// #Warning do not edit this file directly, it is generated by GenerateCombineSignals.scala")
-    line()
-    line("// These are implementations of CombineSignalN used for Signal's `combine` and `combineWith` methods")
-    line()
-    for (n <- from to to) {
-      line("/** @param combinator Must not throw! */")
-      enter(s"class CombineSignal${n}[${tupleType(n)}, Out](") {
-        for (i <- 1 to n) {
-          line(s"parent${i}: SignalSource[T${i}],")
-        }
-        line(s"combinator: (${tupleType(n)}) => Out")
-      }
-      enter(s") extends CombineSignalN[Any, Out](", ")") {
-        line("parents = " + tupleType(n, prefix = "parent", suffix = ".toObservable", separator = " :: ") + " :: Nil,")
-        enter("combinator = seq => combinator(", ")") {
-          for (i <- 1 to n) {
-            line(s"seq(${i - 1}).asInstanceOf[T${i}],")
-          }
-        }
-      }
-      line()
-    }
-    line()
-  }
-
-}
diff --git a/project/GenerateCombineStreams.scala b/project/GenerateCombineStreams.scala
deleted file mode 100644
index ef3f7aef..00000000
--- a/project/GenerateCombineStreams.scala
+++ /dev/null
@@ -1,43 +0,0 @@
-import sbt._
-
-import java.io.File
-
-case class GenerateCombineStreams(
-  sourceDir: File,
-  from: Int,
-  to: Int
-) extends SourceGenerator(
-  sourceDir / "scala" / "com" / "raquo" / "airstream" / "combine" / "generated" / s"CombineStreams.scala"
-) {
-
-  override def apply(): Unit = {
-    line("package com.raquo.airstream.combine.generated")
-    line()
-    line("import com.raquo.airstream.combine.CombineStreamN")
-    line("import com.raquo.airstream.core.Source.EventSource")
-    line()
-    line("// #Warning do not edit this file directly, it is generated by GenerateCombineStreams.scala")
-    line()
-    line("// These are implementations of CombineStreamN used for EventStream's `combine` and `combineWith` methods")
-    line()
-    for (n <- from to to) {
-      line("/** @param combinator Must not throw! */")
-      enter(s"class CombineStream${n}[${tupleType(n)}, Out](") {
-        for (i <- 1 to n) {
-          line(s"parent${i}: EventSource[T${i}],")
-        }
-        line(s"combinator: (${tupleType(n)}) => Out")
-      }
-      enter(s") extends CombineStreamN[Any, Out](", ")") {
-        line("parents = " + tupleType(n, prefix = "parent", suffix = ".toObservable", separator = " :: ") + " :: Nil,")
-        enter("combinator = seq => combinator(", ")") {
-          for (i <- 1 to n) {
-            line(s"seq(${i - 1}).asInstanceOf[T${i}],")
-          }
-        }
-      }
-      line()
-    }
-  }
-
-}
diff --git a/project/GenerateSampleCombineSignals.scala b/project/GenerateSampleCombineSignals.scala
deleted file mode 100644
index 1b16d8b0..00000000
--- a/project/GenerateSampleCombineSignals.scala
+++ /dev/null
@@ -1,47 +0,0 @@
-import sbt._
-
-import java.io.File
-
-case class GenerateSampleCombineSignals(
-  sourceDir: File,
-  from: Int,
-  to: Int
-) extends SourceGenerator(
-  sourceDir / "scala" / "com" / "raquo" / "airstream" / "combine" / "generated" / s"SampleCombineSignals.scala"
-) {
-
-  override def apply(): Unit = {
-    line("package com.raquo.airstream.combine.generated")
-    line()
-    line("import com.raquo.airstream.combine.SampleCombineSignalN")
-    line("import com.raquo.airstream.core.Signal")
-    line("import com.raquo.airstream.core.Source.SignalSource")
-    line()
-    line("// #Warning do not edit this file directly, it is generated by GenerateSampleCombineSignals.scala")
-    line()
-    line("// These are implementations of SampleCombineSignalN used for Signal's `withCurrentValueOf` and `sample` methods")
-    line()
-    for (n <- from to to) {
-      line("/** @param combinator Must not throw! */")
-      enter(s"class SampleCombineSignal${n}[T0, ${tupleType(n - 1)}, Out](") {
-        line("samplingSignal: Signal[T0],")
-        for (i <- 1 until n) {
-          line(s"sampledSignal${i}: SignalSource[T${i}],")
-        }
-        line(s"combinator: (T0, ${tupleType(n - 1)}) => Out")
-      }
-      enter(s") extends SampleCombineSignalN[Any, Out](", ")") {
-        line("samplingSignal = samplingSignal,")
-        line("sampledSignals = " + tupleType(n - 1, prefix = "sampledSignal", suffix = ".toObservable", separator = " :: ") + " :: Nil,")
-        enter("combinator = seq => combinator(", ")") {
-          for (i <- 0 until n) {
-            line(s"seq(${i}).asInstanceOf[T${i}],")
-          }
-        }
-      }
-      line()
-    }
-    line()
-  }
-
-}
diff --git a/project/GenerateSampleCombineStreams.scala b/project/GenerateSampleCombineStreams.scala
deleted file mode 100644
index 87017d4f..00000000
--- a/project/GenerateSampleCombineStreams.scala
+++ /dev/null
@@ -1,47 +0,0 @@
-import sbt._
-
-import java.io.File
-
-case class GenerateSampleCombineStreams(
-  sourceDir: File,
-  from: Int,
-  to: Int
-) extends SourceGenerator(
-  sourceDir / "scala" / "com" / "raquo" / "airstream" / "combine" / "generated" / s"SampleCombineStreams.scala"
-) {
-
-  override def apply(): Unit = {
-    line("package com.raquo.airstream.combine.generated")
-    line()
-    line("import com.raquo.airstream.combine.SampleCombineStreamN")
-    line("import com.raquo.airstream.core.EventStream")
-    line("import com.raquo.airstream.core.Source.SignalSource")
-    line()
-    line("// #Warning do not edit this file directly, it is generated by GenerateSampleCombineStreams.scala")
-    line()
-    line("// These are implementations of SampleCombineStreamN used for EventStream's `withCurrentValueOf` and `sample` methods")
-    line()
-    for (n <- from to to) {
-      line("/** @param combinator Must not throw! */")
-      enter(s"class SampleCombineStream${n}[T0, ${tupleType(n - 1)}, Out](") {
-        line("samplingStream: EventStream[T0],")
-        for (i <- 1 until n) {
-          line(s"sampledSignal${i}: SignalSource[T${i}],")
-        }
-        line(s"combinator: (T0, ${tupleType(n - 1)}) => Out")
-      }
-      enter(s") extends SampleCombineStreamN[Any, Out](", ")") {
-        line("samplingStream = samplingStream,")
-        line("sampledSignals = " + tupleType(n - 1, "sampledSignal", ".toObservable", separator = " :: ") + " :: Nil,")
-        enter("combinator = seq => combinator(", ")") {
-          for (i <- 0 until n) {
-            line(s"seq(${i}).asInstanceOf[T${i}],")
-          }
-        }
-      }
-      line()
-    }
-    line()
-  }
-
-}
diff --git a/project/GenerateStaticSignalCombineOps.scala b/project/GenerateStaticSignalCombineOps.scala
index 35994b43..0e9e20fb 100644
--- a/project/GenerateStaticSignalCombineOps.scala
+++ b/project/GenerateStaticSignalCombineOps.scala
@@ -13,8 +13,10 @@ case class GenerateStaticSignalCombineOps(
   override def apply(): Unit = {
     line("package com.raquo.airstream.combine.generated")
     line()
+    line("import com.raquo.airstream.combine.CombineSignalN")
     line("import com.raquo.airstream.core.Signal")
     line("import com.raquo.airstream.core.Source.SignalSource")
+    line("import com.raquo.ew.JsArray")
     line()
     line("// #Warning do not edit this file directly, it is generated by GenerateStaticSignalCombineOps.scala")
     line()
@@ -39,7 +41,19 @@ case class GenerateStaticSignalCombineOps(
           line(s"combinator: (${tupleType(n)}) => Out")
         }
         enter(s"): Signal[Out] = {", "}") {
-          line(s"new CombineSignal${n}(${tupleType(n, "s")}, combinator)")
+          // line(s"val parents = JsArray(${tupleType(n, "s", ".toObservable")})")
+          // line(s"val arrCombinator = (arr: JsArray[Any]) => combinator(${(0 until n).map(i => s"arr(${i}).asInstanceOf[T${i + 1}]").mkString(", ")})")
+          // enter("new CombineSignalN(", ")") {
+          //   line("parents, arrCombinator")
+          // }
+          enter("new CombineSignalN[Any, Out](", ")") {
+            line(s"parents = JsArray(${tupleType(n, "s", ".toObservable")}),")
+            enter(s"combinator = arr => combinator(", ")") {
+              for (i <- 0 until n) {
+                line(s"arr(${i}).asInstanceOf[T${i+1}],")
+              }
+            }
+          }
         }
         line()
         line("// --")
diff --git a/project/GenerateStaticStreamCombineOps.scala b/project/GenerateStaticStreamCombineOps.scala
index b5e897c6..339a66f8 100644
--- a/project/GenerateStaticStreamCombineOps.scala
+++ b/project/GenerateStaticStreamCombineOps.scala
@@ -13,8 +13,10 @@ case class GenerateStaticStreamCombineOps(
   override def apply(): Unit = {
     line("package com.raquo.airstream.combine.generated")
     line()
+    line("import com.raquo.airstream.combine.CombineStreamN")
     line("import com.raquo.airstream.core.EventStream")
     line("import com.raquo.airstream.core.Source.EventSource")
+    line("import com.raquo.ew.JsArray")
     line()
     line("// #Warning do not edit this file directly, it is generated by GenerateStaticStreamCombineOps.scala")
     line()
@@ -39,7 +41,19 @@ case class GenerateStaticStreamCombineOps(
           line(s"combinator: (${tupleType(n)}) => Out")
         }
         enter(s"): EventStream[Out] = {", "}") {
-          line(s"new CombineStream${n}(${tupleType(n, "s")}, combinator)")
+          // line(s"val arrCombinator = (arr: JsArray[Any]) => combinator(${(0 until n).map(i => s"arr(${i}).asInstanceOf[T${i + 1}]").mkString(", ")})")
+          // line(s"val streams = JsArray[EventStream[Any]](${tupleType(n, "s", ".toObservable")})")
+          // enter("new CombineStreamN(", ")") {
+          //   line("streams, arrCombinator")
+          // }
+          enter("new CombineStreamN[Any, Out](", ")") {
+            line(s"parentStreams = JsArray(${tupleType(n, "s", ".toObservable")}),")
+            enter(s"combinator = arr => combinator(", ")") {
+              for (i <- 0 until n) {
+                line(s"arr(${i}).asInstanceOf[T${i + 1}],")
+              }
+            }
+          }
         }
         line()
         line("// --")
diff --git a/project/Versions.scala b/project/Versions.scala
index 61d99a86..f83c0147 100644
--- a/project/Versions.scala
+++ b/project/Versions.scala
@@ -10,7 +10,7 @@ object Versions {
 
   val Tuplez = "0.3.7"
 
-  val Ew = "0.1.1"
+  val Ew = "0.1.2-SNAPSHOT"
 
   // Used in test only:
 
diff --git a/src/main/scala/com/raquo/airstream/combine/CombineObservable.scala b/src/main/scala/com/raquo/airstream/combine/CombineObservable.scala
index ed1b75d0..20bc5128 100644
--- a/src/main/scala/com/raquo/airstream/combine/CombineObservable.scala
+++ b/src/main/scala/com/raquo/airstream/combine/CombineObservable.scala
@@ -66,20 +66,21 @@ object CombineObservable {
     }
   }
 
-  /** @param combinator MUST NOT THROW! */
-  def seqCombinator[A, B](trys: Seq[Try[A]], combinator: Seq[A] => B): Try[B] = {
-    // @TODO[Performance] typical combinator will access every value by index,
-    //  but `trys` could be a List or something with an O(N) cost for this.
-    //  However, I don't think initializing an Array in all cases will be
-    //  cheaper, because typical seq sizes are very small here (2-4)
-    if (trys.forall(_.isSuccess)) {
+  def jsArrayCombinator[A, B](trys: JsArray[Try[A]], combinator: JsArray[A] => B): Try[B] = {
+    var allSuccess: Boolean = true
+    trys.forEach { t =>
+      if (t.isFailure) {
+        allSuccess = false
+      }
+    }
+    if (allSuccess) {
       val values = trys.map(_.get)
       Success(combinator(values))
     } else {
       val errors = trys.map {
         case Failure(err) => Some(err)
         case _ => None
-      }
+      }.asScalaJs.toSeq
       Failure(CombinedError(errors))
     }
   }
diff --git a/src/main/scala/com/raquo/airstream/combine/CombineSignalN.scala b/src/main/scala/com/raquo/airstream/combine/CombineSignalN.scala
index d4dd4933..c92f63b6 100644
--- a/src/main/scala/com/raquo/airstream/combine/CombineSignalN.scala
+++ b/src/main/scala/com/raquo/airstream/combine/CombineSignalN.scala
@@ -2,33 +2,37 @@ package com.raquo.airstream.combine
 
 import com.raquo.airstream.common.{InternalParentObserver, MultiParentSignal}
 import com.raquo.airstream.core.{Protected, Signal}
+import com.raquo.ew.JsArray
 
 import scala.util.Try
 
-/** @param combinator Must not throw! Must be pure. */
+/**
+  * @param parents Never update this array - this signal owns it.
+  * @param combinator Must not throw! Must be pure.
+  */
 class CombineSignalN[A, Out](
-  override protected[this] val parents: Seq[Signal[A]],
-  protected[this] val combinator: Seq[A] => Out
+  override protected[this] val parents: JsArray[Signal[A]],
+  protected[this] val combinator: JsArray[A] => Out
 ) extends MultiParentSignal[A, Out] with CombineObservable[Out] {
 
   // @TODO[API] Maybe this should throw if parents.isEmpty
 
-  override protected val topoRank: Int = Protected.maxTopoRank(parents) + 1
+  override protected val topoRank: Int = Protected.maxTopoRank(0, parents) + 1
 
   override protected[this] def inputsReady: Boolean = true
 
   override protected[this] def combinedValue: Try[Out] = {
-    CombineObservable.seqCombinator(parents.map(_.tryNow()), combinator)
+    CombineObservable.jsArrayCombinator(parents.map(_.tryNow()), combinator)
   }
 
   override protected def currentValueFromParent(): Try[Out] = combinedValue
 
-  parentObservers.push(
-    parents.map { parent =>
+  parents.forEach { parent =>
+    parentObservers.push(
       InternalParentObserver.fromTry[A](parent, (_, transaction) => {
         onInputsReady(transaction)
       })
-    }: _*
-  )
+    )
+  }
 
 }
diff --git a/src/main/scala/com/raquo/airstream/combine/CombineStreamN.scala b/src/main/scala/com/raquo/airstream/combine/CombineStreamN.scala
index 657e54ab..f7ea8396 100644
--- a/src/main/scala/com/raquo/airstream/combine/CombineStreamN.scala
+++ b/src/main/scala/com/raquo/airstream/combine/CombineStreamN.scala
@@ -1,43 +1,60 @@
 package com.raquo.airstream.combine
 
 import com.raquo.airstream.common.{InternalParentObserver, MultiParentStream}
-import com.raquo.airstream.core.{EventStream, Protected}
+import com.raquo.airstream.core.{EventStream, Observable, Protected}
+import com.raquo.ew.JsArray
 
+import scala.scalajs.js
 import scala.util.Try
 
-/** @param combinator Must not throw! */
+/**
+  * @param parentStreams Never update this array - this stream owns it.
+  * @param combinator Must not throw! Must be pure.
+  */
 class CombineStreamN[A, Out](
-  override protected[this] val parents: Seq[EventStream[A]],
-  combinator: Seq[A] => Out
+  parentStreams: JsArray[EventStream[A]],
+  combinator: JsArray[A] => Out
 ) extends MultiParentStream[A, Out] with CombineObservable[Out] {
 
   // @TODO[API] Maybe this should throw if parents.isEmpty
 
+  override protected[this] val parents: JsArray[Observable[A]] = {
+    // #Note this is safe as long as we don't put non-streams into this JsArray.
+    parentStreams.asInstanceOf[JsArray[Observable[A]]]
+  }
+
   override protected val topoRank: Int = Protected.maxTopoRank(parents) + 1
 
-  private[this] val maybeLastParentValues: Array[Option[Try[A]]] = Array.fill(parents.size)(None)
+  private[this] val maybeLastParentValues: JsArray[js.UndefOr[Try[A]]] = parents.map(_ => js.undefined)
 
   override protected[this] def inputsReady: Boolean = {
-    maybeLastParentValues.forall(_.nonEmpty)
+    var allReady: Boolean = true
+    maybeLastParentValues.forEach { lastValue =>
+      if (lastValue.isEmpty) {
+        allReady = false
+      }
+    }
+    allReady
   }
 
   override protected[this] def combinedValue: Try[Out] = {
-    // @TODO[Scala3] When we don't need Scala 2.12, use ArraySeq.unsafeWrapArray(maybeLastParentValues) for perf?
-    CombineObservable.seqCombinator(maybeLastParentValues.toIndexedSeq.map(_.get), combinator)
+    // #Note don't call this unless you have first verified that
+    //  inputs are ready, otherwise this asInstanceOf will not be safe.
+    CombineObservable.jsArrayCombinator(maybeLastParentValues.asInstanceOf[JsArray[Try[A]]], combinator)
   }
 
-  parentObservers.push(
-    parents.zipWithIndex.map { case (parent, index) =>
+  parents.forEachWithIndex { (parent, ix) =>
+    parentObservers.push(
       InternalParentObserver.fromTry[A](
         parent,
         (nextParentValue, transaction) => {
-          maybeLastParentValues.update(index, Some(nextParentValue))
+          maybeLastParentValues.update(ix, nextParentValue)
           if (inputsReady) {
             onInputsReady(transaction)
           }
         }
       )
-    }: _*
-  )
+    )
+  }
 
 }
diff --git a/src/main/scala/com/raquo/airstream/combine/MergeStream.scala b/src/main/scala/com/raquo/airstream/combine/MergeStream.scala
index 73c2e6dd..c5cd7d8e 100644
--- a/src/main/scala/com/raquo/airstream/combine/MergeStream.scala
+++ b/src/main/scala/com/raquo/airstream/combine/MergeStream.scala
@@ -11,11 +11,18 @@ import com.raquo.ew.JsArray
   *
   * This feature exists only for EventStream-s because merging Signals
   * does not make sense, conceptually (what do you even do with their current values?).
+  *
+  * @param parentStreams Never update this array - this stream owns it.
   */
 class MergeStream[A](
-  override protected[this] val parents: Seq[EventStream[A]],
+  parentStreams: JsArray[EventStream[A]],
 ) extends WritableStream[A] with SyncObservable[A] with MultiParentStream[A, A] {
 
+  override protected[this] val parents: JsArray[Observable[A]] = {
+    // This cast is safe as long as we don't put signals into this array
+    parentStreams.asInstanceOf[JsArray[Observable[A]]]
+  }
+
   override protected val topoRank: Int = Protected.maxTopoRank(parents) + 1
 
   private[this] val pendingParentValues: JsPriorityQueue[Observation[A]] = {
@@ -24,7 +31,7 @@ class MergeStream[A](
 
   private[this] val parentObservers: JsArray[InternalParentObserver[A]] = JsArray()
 
-  parents.foreach(parent => parentObservers.push(makeInternalObserver(parent)))
+  parents.forEach(parent => parentObservers.push(makeInternalObserver(parent)))
 
   // @TODO document this, and document the topo parent order
   /** If this stream has already fired in a given transaction, the next firing will happen in a new transaction.
diff --git a/src/main/scala/com/raquo/airstream/combine/SampleCombineSignalN.scala b/src/main/scala/com/raquo/airstream/combine/SampleCombineSignalN.scala
index 1b1ccca7..bf3bf73a 100644
--- a/src/main/scala/com/raquo/airstream/combine/SampleCombineSignalN.scala
+++ b/src/main/scala/com/raquo/airstream/combine/SampleCombineSignalN.scala
@@ -2,6 +2,7 @@ package com.raquo.airstream.combine
 
 import com.raquo.airstream.common.{InternalParentObserver, MultiParentSignal}
 import com.raquo.airstream.core.{Protected, Signal}
+import com.raquo.ew.JsArray
 
 import scala.util.Try
 
@@ -12,23 +13,31 @@ import scala.util.Try
   *
   * Works similar to Rx's "withLatestFrom", except without glitches (see a diamond case test for this in GlitchSpec).
   *
+  * @param sampledSignals - Never update this array - this signal owns it.
+  *
   * @param combinator Note: Must not throw! Must be pure.
   */
 class SampleCombineSignalN[A, Out](
   samplingSignal: Signal[A],
-  sampledSignals: Seq[Signal[A]],
-  combinator: Seq[A] => Out
+  sampledSignals: JsArray[Signal[A]],
+  combinator: JsArray[A] => Out
 ) extends MultiParentSignal[A, Out] with CombineObservable[Out] {
 
-  override protected val topoRank: Int = (Protected.topoRank(samplingSignal) max Protected.maxTopoRank(sampledSignals)) + 1
+  override protected val topoRank: Int = Protected.maxTopoRank(samplingSignal, sampledSignals) + 1
 
   override protected[this] def inputsReady: Boolean = true
 
-  override protected[this] val parents: Seq[Signal[A]] = samplingSignal +: sampledSignals
+  override protected[this] val parents: JsArray[Signal[A]] = combineWithArray(
+    samplingSignal,
+    sampledSignals
+  )
 
   override protected[this] def combinedValue: Try[Out] = {
-    val values = (samplingSignal +: sampledSignals).map(_.tryNow())
-    CombineObservable.seqCombinator(values, combinator)
+    val values = combineWithArray(
+      samplingSignal.tryNow(),
+      sampledSignals.map(_.tryNow())
+    )
+    CombineObservable.jsArrayCombinator(values, combinator)
   }
 
   override protected def currentValueFromParent(): Try[Out] = combinedValue
@@ -39,11 +48,17 @@ class SampleCombineSignalN[A, Out](
     })
   )
 
-  parentObservers.push(
-    sampledSignals.map { sampledSignal =>
+  sampledSignals.forEach { sampledSignal =>
+    parentObservers.push(
       InternalParentObserver.fromTry[A](sampledSignal, (_, _) => {
         // Do nothing, we just want to ensure that sampledSignal is started.
       })
-    }: _*
-  )
+    )
+  }
+
+  private[this] def combineWithArray[V](sampling: V, sampled: JsArray[V]): JsArray[V] = {
+    val values = sampled.concat() // There's also JsArray.from, but it does not work in IE11
+    values.unshift(sampling)
+    values
+  }
 }
diff --git a/src/main/scala/com/raquo/airstream/combine/SampleCombineStreamN.scala b/src/main/scala/com/raquo/airstream/combine/SampleCombineStreamN.scala
index 931d2e7c..61dbaece 100644
--- a/src/main/scala/com/raquo/airstream/combine/SampleCombineStreamN.scala
+++ b/src/main/scala/com/raquo/airstream/combine/SampleCombineStreamN.scala
@@ -2,6 +2,7 @@ package com.raquo.airstream.combine
 
 import com.raquo.airstream.common.{InternalParentObserver, MultiParentStream}
 import com.raquo.airstream.core.{EventStream, Observable, Protected, Signal, Transaction}
+import com.raquo.ew.JsArray
 
 import scala.scalajs.js
 import scala.util.Try
@@ -13,25 +14,32 @@ import scala.util.Try
   *
   * Works similar to Rx's "withLatestFrom", except without glitches (see a diamond case test for this in GlitchSpec).
   *
+  * @param sampledSignals Never update this array - this stream owns it.
   * @param combinator Note: Must not throw!
   */
 class SampleCombineStreamN[A, Out](
   samplingStream: EventStream[A],
-  sampledSignals: Seq[Signal[A]],
-  combinator: Seq[A] => Out
+  sampledSignals: JsArray[Signal[A]],
+  combinator: JsArray[A] => Out
 ) extends MultiParentStream[A, Out] with CombineObservable[Out] {
 
-  override protected val topoRank: Int = (Protected.topoRank(samplingStream) max Protected.maxTopoRank(sampledSignals)) + 1
+  override protected val topoRank: Int = Protected.maxTopoRank(samplingStream, sampledSignals) + 1
 
   private[this] var maybeLastSamplingValue: js.UndefOr[Try[A]] = js.undefined
 
   override protected[this] def inputsReady: Boolean = maybeLastSamplingValue.nonEmpty
 
-  override protected[this] val parents: Seq[Observable[A]] = samplingStream +: sampledSignals
+  override protected[this] val parents: JsArray[Observable[A]] = combineWithArray(
+    samplingStream,
+    sampledSignals
+  )
 
   override protected[this] def combinedValue: Try[Out] = {
-    val parentValues = maybeLastSamplingValue.get +: sampledSignals.map(_.tryNow())
-    CombineObservable.seqCombinator(parentValues, combinator)
+    val values = combineWithArray(
+      maybeLastSamplingValue.get,
+      sampledSignals.map(_.tryNow())
+    )
+    CombineObservable.jsArrayCombinator(values, combinator)
   }
 
   parentObservers.push(
@@ -44,17 +52,22 @@ class SampleCombineStreamN[A, Out](
     )
   )
 
-  parentObservers.push(
-    sampledSignals.map { sampledSignal =>
+  sampledSignals.forEach { sampledSignal =>
+    parentObservers.push(
       InternalParentObserver.fromTry[A](sampledSignal, (_, _) => {
         // Do nothing, we just want to ensure that sampledSignal is started.
       })
-    }: _*
-  )
+    )
+  }
 
   override private[airstream] def syncFire(transaction: Transaction): Unit = {
     super.syncFire(transaction)
     maybeLastSamplingValue = js.undefined // Clean up memory, as we don't need this reference anymore
   }
 
+  private[this] def combineWithArray[BaseV >: V, V](sampling: BaseV, sampled: JsArray[V]): JsArray[BaseV] = {
+    val values = sampled.concat[BaseV]() // There's also JsArray.from, but it does not work in IE11
+    values.unshift(sampling)
+    values
+  }
 }
diff --git a/src/main/scala/com/raquo/airstream/combine/generated/CombinableSignal.scala b/src/main/scala/com/raquo/airstream/combine/generated/CombinableSignal.scala
index 8f9ff317..43e3f0ad 100644
--- a/src/main/scala/com/raquo/airstream/combine/generated/CombinableSignal.scala
+++ b/src/main/scala/com/raquo/airstream/combine/generated/CombinableSignal.scala
@@ -1,8 +1,10 @@
 package com.raquo.airstream.combine.generated
 
 import app.tulz.tuplez.Composition
+import com.raquo.airstream.combine.SampleCombineSignalN
 import com.raquo.airstream.core.Signal
 import com.raquo.airstream.core.Source.SignalSource
+import com.raquo.ew.JsArray
 
 // #Warning do not edit this file directly, it is generated by GenerateCombinableSignal.scala
 
@@ -23,20 +25,27 @@ class CombinableSignal[A](val signal: Signal[A]) extends AnyVal {
   )(
     combinator: (A, T1) => Out
   ): Signal[Out] = {
-    new CombineSignal2(signal, s1, combinator)
+    StaticSignalCombineOps.combineWithFn(signal, s1)(combinator)
   }
 
   def withCurrentValueOf[T1](
     s1: SignalSource[T1]
   )(implicit c: Composition[A, (T1)]): Signal[c.Composed] = {
-    val combinator = (a: A, v1: T1) => c.compose(a, (v1))
-    new SampleCombineSignal2(signal, s1, combinator)
+    val combinator = (arr: JsArray[Any]) => c.compose(arr(0).asInstanceOf[A], (arr(1).asInstanceOf[T1]))
+    val sampledSignals = JsArray[Signal[Any]](s1.toObservable)
+    new SampleCombineSignalN(
+      signal, sampledSignals, combinator
+    )
   }
 
   def sample[T1](
     s1: SignalSource[T1]
   ): Signal[(T1)] = {
-    new SampleCombineSignal2[A, T1, (T1)](signal, s1, (_, v1) => (v1))
+    val combinator = (arr: JsArray[Any]) => (arr(1).asInstanceOf[T1])
+    val sampledSignals = JsArray[Signal[Any]](s1.toObservable)
+    new SampleCombineSignalN[Any, (T1)](
+      signal, sampledSignals, combinator
+    )
   }
 
   // --
@@ -53,20 +62,27 @@ class CombinableSignal[A](val signal: Signal[A]) extends AnyVal {
   )(
     combinator: (A, T1, T2) => Out
   ): Signal[Out] = {
-    new CombineSignal3(signal, s1, s2, combinator)
+    StaticSignalCombineOps.combineWithFn(signal, s1, s2)(combinator)
   }
 
   def withCurrentValueOf[T1, T2](
     s1: SignalSource[T1], s2: SignalSource[T2]
   )(implicit c: Composition[A, (T1, T2)]): Signal[c.Composed] = {
-    val combinator = (a: A, v1: T1, v2: T2) => c.compose(a, (v1, v2))
-    new SampleCombineSignal3(signal, s1, s2, combinator)
+    val combinator = (arr: JsArray[Any]) => c.compose(arr(0).asInstanceOf[A], (arr(1).asInstanceOf[T1], arr(2).asInstanceOf[T2]))
+    val sampledSignals = JsArray[Signal[Any]](s1.toObservable, s2.toObservable)
+    new SampleCombineSignalN(
+      signal, sampledSignals, combinator
+    )
   }
 
   def sample[T1, T2](
     s1: SignalSource[T1], s2: SignalSource[T2]
   ): Signal[(T1, T2)] = {
-    new SampleCombineSignal3[A, T1, T2, (T1, T2)](signal, s1, s2, (_, v1, v2) => (v1, v2))
+    val combinator = (arr: JsArray[Any]) => (arr(1).asInstanceOf[T1], arr(2).asInstanceOf[T2])
+    val sampledSignals = JsArray[Signal[Any]](s1.toObservable, s2.toObservable)
+    new SampleCombineSignalN[Any, (T1, T2)](
+      signal, sampledSignals, combinator
+    )
   }
 
   // --
@@ -83,20 +99,27 @@ class CombinableSignal[A](val signal: Signal[A]) extends AnyVal {
   )(
     combinator: (A, T1, T2, T3) => Out
   ): Signal[Out] = {
-    new CombineSignal4(signal, s1, s2, s3, combinator)
+    StaticSignalCombineOps.combineWithFn(signal, s1, s2, s3)(combinator)
   }
 
   def withCurrentValueOf[T1, T2, T3](
     s1: SignalSource[T1], s2: SignalSource[T2], s3: SignalSource[T3]
   )(implicit c: Composition[A, (T1, T2, T3)]): Signal[c.Composed] = {
-    val combinator = (a: A, v1: T1, v2: T2, v3: T3) => c.compose(a, (v1, v2, v3))
-    new SampleCombineSignal4(signal, s1, s2, s3, combinator)
+    val combinator = (arr: JsArray[Any]) => c.compose(arr(0).asInstanceOf[A], (arr(1).asInstanceOf[T1], arr(2).asInstanceOf[T2], arr(3).asInstanceOf[T3]))
+    val sampledSignals = JsArray[Signal[Any]](s1.toObservable, s2.toObservable, s3.toObservable)
+    new SampleCombineSignalN(
+      signal, sampledSignals, combinator
+    )
   }
 
   def sample[T1, T2, T3](
     s1: SignalSource[T1], s2: SignalSource[T2], s3: SignalSource[T3]
   ): Signal[(T1, T2, T3)] = {
-    new SampleCombineSignal4[A, T1, T2, T3, (T1, T2, T3)](signal, s1, s2, s3, (_, v1, v2, v3) => (v1, v2, v3))
+    val combinator = (arr: JsArray[Any]) => (arr(1).asInstanceOf[T1], arr(2).asInstanceOf[T2], arr(3).asInstanceOf[T3])
+    val sampledSignals = JsArray[Signal[Any]](s1.toObservable, s2.toObservable, s3.toObservable)
+    new SampleCombineSignalN[Any, (T1, T2, T3)](
+      signal, sampledSignals, combinator
+    )
   }
 
   // --
@@ -113,20 +136,27 @@ class CombinableSignal[A](val signal: Signal[A]) extends AnyVal {
   )(
     combinator: (A, T1, T2, T3, T4) => Out
   ): Signal[Out] = {
-    new CombineSignal5(signal, s1, s2, s3, s4, combinator)
+    StaticSignalCombineOps.combineWithFn(signal, s1, s2, s3, s4)(combinator)
   }
 
   def withCurrentValueOf[T1, T2, T3, T4](
     s1: SignalSource[T1], s2: SignalSource[T2], s3: SignalSource[T3], s4: SignalSource[T4]
   )(implicit c: Composition[A, (T1, T2, T3, T4)]): Signal[c.Composed] = {
-    val combinator = (a: A, v1: T1, v2: T2, v3: T3, v4: T4) => c.compose(a, (v1, v2, v3, v4))
-    new SampleCombineSignal5(signal, s1, s2, s3, s4, combinator)
+    val combinator = (arr: JsArray[Any]) => c.compose(arr(0).asInstanceOf[A], (arr(1).asInstanceOf[T1], arr(2).asInstanceOf[T2], arr(3).asInstanceOf[T3], arr(4).asInstanceOf[T4]))
+    val sampledSignals = JsArray[Signal[Any]](s1.toObservable, s2.toObservable, s3.toObservable, s4.toObservable)
+    new SampleCombineSignalN(
+      signal, sampledSignals, combinator
+    )
   }
 
   def sample[T1, T2, T3, T4](
     s1: SignalSource[T1], s2: SignalSource[T2], s3: SignalSource[T3], s4: SignalSource[T4]
   ): Signal[(T1, T2, T3, T4)] = {
-    new SampleCombineSignal5[A, T1, T2, T3, T4, (T1, T2, T3, T4)](signal, s1, s2, s3, s4, (_, v1, v2, v3, v4) => (v1, v2, v3, v4))
+    val combinator = (arr: JsArray[Any]) => (arr(1).asInstanceOf[T1], arr(2).asInstanceOf[T2], arr(3).asInstanceOf[T3], arr(4).asInstanceOf[T4])
+    val sampledSignals = JsArray[Signal[Any]](s1.toObservable, s2.toObservable, s3.toObservable, s4.toObservable)
+    new SampleCombineSignalN[Any, (T1, T2, T3, T4)](
+      signal, sampledSignals, combinator
+    )
   }
 
   // --
@@ -143,20 +173,27 @@ class CombinableSignal[A](val signal: Signal[A]) extends AnyVal {
   )(
     combinator: (A, T1, T2, T3, T4, T5) => Out
   ): Signal[Out] = {
-    new CombineSignal6(signal, s1, s2, s3, s4, s5, combinator)
+    StaticSignalCombineOps.combineWithFn(signal, s1, s2, s3, s4, s5)(combinator)
   }
 
   def withCurrentValueOf[T1, T2, T3, T4, T5](
     s1: SignalSource[T1], s2: SignalSource[T2], s3: SignalSource[T3], s4: SignalSource[T4], s5: SignalSource[T5]
   )(implicit c: Composition[A, (T1, T2, T3, T4, T5)]): Signal[c.Composed] = {
-    val combinator = (a: A, v1: T1, v2: T2, v3: T3, v4: T4, v5: T5) => c.compose(a, (v1, v2, v3, v4, v5))
-    new SampleCombineSignal6(signal, s1, s2, s3, s4, s5, combinator)
+    val combinator = (arr: JsArray[Any]) => c.compose(arr(0).asInstanceOf[A], (arr(1).asInstanceOf[T1], arr(2).asInstanceOf[T2], arr(3).asInstanceOf[T3], arr(4).asInstanceOf[T4], arr(5).asInstanceOf[T5]))
+    val sampledSignals = JsArray[Signal[Any]](s1.toObservable, s2.toObservable, s3.toObservable, s4.toObservable, s5.toObservable)
+    new SampleCombineSignalN(
+      signal, sampledSignals, combinator
+    )
   }
 
   def sample[T1, T2, T3, T4, T5](
     s1: SignalSource[T1], s2: SignalSource[T2], s3: SignalSource[T3], s4: SignalSource[T4], s5: SignalSource[T5]
   ): Signal[(T1, T2, T3, T4, T5)] = {
-    new SampleCombineSignal6[A, T1, T2, T3, T4, T5, (T1, T2, T3, T4, T5)](signal, s1, s2, s3, s4, s5, (_, v1, v2, v3, v4, v5) => (v1, v2, v3, v4, v5))
+    val combinator = (arr: JsArray[Any]) => (arr(1).asInstanceOf[T1], arr(2).asInstanceOf[T2], arr(3).asInstanceOf[T3], arr(4).asInstanceOf[T4], arr(5).asInstanceOf[T5])
+    val sampledSignals = JsArray[Signal[Any]](s1.toObservable, s2.toObservable, s3.toObservable, s4.toObservable, s5.toObservable)
+    new SampleCombineSignalN[Any, (T1, T2, T3, T4, T5)](
+      signal, sampledSignals, combinator
+    )
   }
 
   // --
@@ -173,20 +210,27 @@ class CombinableSignal[A](val signal: Signal[A]) extends AnyVal {
   )(
     combinator: (A, T1, T2, T3, T4, T5, T6) => Out
   ): Signal[Out] = {
-    new CombineSignal7(signal, s1, s2, s3, s4, s5, s6, combinator)
+    StaticSignalCombineOps.combineWithFn(signal, s1, s2, s3, s4, s5, s6)(combinator)
   }
 
   def withCurrentValueOf[T1, T2, T3, T4, T5, T6](
     s1: SignalSource[T1], s2: SignalSource[T2], s3: SignalSource[T3], s4: SignalSource[T4], s5: SignalSource[T5], s6: SignalSource[T6]
   )(implicit c: Composition[A, (T1, T2, T3, T4, T5, T6)]): Signal[c.Composed] = {
-    val combinator = (a: A, v1: T1, v2: T2, v3: T3, v4: T4, v5: T5, v6: T6) => c.compose(a, (v1, v2, v3, v4, v5, v6))
-    new SampleCombineSignal7(signal, s1, s2, s3, s4, s5, s6, combinator)
+    val combinator = (arr: JsArray[Any]) => c.compose(arr(0).asInstanceOf[A], (arr(1).asInstanceOf[T1], arr(2).asInstanceOf[T2], arr(3).asInstanceOf[T3], arr(4).asInstanceOf[T4], arr(5).asInstanceOf[T5], arr(6).asInstanceOf[T6]))
+    val sampledSignals = JsArray[Signal[Any]](s1.toObservable, s2.toObservable, s3.toObservable, s4.toObservable, s5.toObservable, s6.toObservable)
+    new SampleCombineSignalN(
+      signal, sampledSignals, combinator
+    )
   }
 
   def sample[T1, T2, T3, T4, T5, T6](
     s1: SignalSource[T1], s2: SignalSource[T2], s3: SignalSource[T3], s4: SignalSource[T4], s5: SignalSource[T5], s6: SignalSource[T6]
   ): Signal[(T1, T2, T3, T4, T5, T6)] = {
-    new SampleCombineSignal7[A, T1, T2, T3, T4, T5, T6, (T1, T2, T3, T4, T5, T6)](signal, s1, s2, s3, s4, s5, s6, (_, v1, v2, v3, v4, v5, v6) => (v1, v2, v3, v4, v5, v6))
+    val combinator = (arr: JsArray[Any]) => (arr(1).asInstanceOf[T1], arr(2).asInstanceOf[T2], arr(3).asInstanceOf[T3], arr(4).asInstanceOf[T4], arr(5).asInstanceOf[T5], arr(6).asInstanceOf[T6])
+    val sampledSignals = JsArray[Signal[Any]](s1.toObservable, s2.toObservable, s3.toObservable, s4.toObservable, s5.toObservable, s6.toObservable)
+    new SampleCombineSignalN[Any, (T1, T2, T3, T4, T5, T6)](
+      signal, sampledSignals, combinator
+    )
   }
 
   // --
@@ -203,20 +247,27 @@ class CombinableSignal[A](val signal: Signal[A]) extends AnyVal {
   )(
     combinator: (A, T1, T2, T3, T4, T5, T6, T7) => Out
   ): Signal[Out] = {
-    new CombineSignal8(signal, s1, s2, s3, s4, s5, s6, s7, combinator)
+    StaticSignalCombineOps.combineWithFn(signal, s1, s2, s3, s4, s5, s6, s7)(combinator)
   }
 
   def withCurrentValueOf[T1, T2, T3, T4, T5, T6, T7](
     s1: SignalSource[T1], s2: SignalSource[T2], s3: SignalSource[T3], s4: SignalSource[T4], s5: SignalSource[T5], s6: SignalSource[T6], s7: SignalSource[T7]
   )(implicit c: Composition[A, (T1, T2, T3, T4, T5, T6, T7)]): Signal[c.Composed] = {
-    val combinator = (a: A, v1: T1, v2: T2, v3: T3, v4: T4, v5: T5, v6: T6, v7: T7) => c.compose(a, (v1, v2, v3, v4, v5, v6, v7))
-    new SampleCombineSignal8(signal, s1, s2, s3, s4, s5, s6, s7, combinator)
+    val combinator = (arr: JsArray[Any]) => c.compose(arr(0).asInstanceOf[A], (arr(1).asInstanceOf[T1], arr(2).asInstanceOf[T2], arr(3).asInstanceOf[T3], arr(4).asInstanceOf[T4], arr(5).asInstanceOf[T5], arr(6).asInstanceOf[T6], arr(7).asInstanceOf[T7]))
+    val sampledSignals = JsArray[Signal[Any]](s1.toObservable, s2.toObservable, s3.toObservable, s4.toObservable, s5.toObservable, s6.toObservable, s7.toObservable)
+    new SampleCombineSignalN(
+      signal, sampledSignals, combinator
+    )
   }
 
   def sample[T1, T2, T3, T4, T5, T6, T7](
     s1: SignalSource[T1], s2: SignalSource[T2], s3: SignalSource[T3], s4: SignalSource[T4], s5: SignalSource[T5], s6: SignalSource[T6], s7: SignalSource[T7]
   ): Signal[(T1, T2, T3, T4, T5, T6, T7)] = {
-    new SampleCombineSignal8[A, T1, T2, T3, T4, T5, T6, T7, (T1, T2, T3, T4, T5, T6, T7)](signal, s1, s2, s3, s4, s5, s6, s7, (_, v1, v2, v3, v4, v5, v6, v7) => (v1, v2, v3, v4, v5, v6, v7))
+    val combinator = (arr: JsArray[Any]) => (arr(1).asInstanceOf[T1], arr(2).asInstanceOf[T2], arr(3).asInstanceOf[T3], arr(4).asInstanceOf[T4], arr(5).asInstanceOf[T5], arr(6).asInstanceOf[T6], arr(7).asInstanceOf[T7])
+    val sampledSignals = JsArray[Signal[Any]](s1.toObservable, s2.toObservable, s3.toObservable, s4.toObservable, s5.toObservable, s6.toObservable, s7.toObservable)
+    new SampleCombineSignalN[Any, (T1, T2, T3, T4, T5, T6, T7)](
+      signal, sampledSignals, combinator
+    )
   }
 
   // --
@@ -233,20 +284,27 @@ class CombinableSignal[A](val signal: Signal[A]) extends AnyVal {
   )(
     combinator: (A, T1, T2, T3, T4, T5, T6, T7, T8) => Out
   ): Signal[Out] = {
-    new CombineSignal9(signal, s1, s2, s3, s4, s5, s6, s7, s8, combinator)
+    StaticSignalCombineOps.combineWithFn(signal, s1, s2, s3, s4, s5, s6, s7, s8)(combinator)
   }
 
   def withCurrentValueOf[T1, T2, T3, T4, T5, T6, T7, T8](
     s1: SignalSource[T1], s2: SignalSource[T2], s3: SignalSource[T3], s4: SignalSource[T4], s5: SignalSource[T5], s6: SignalSource[T6], s7: SignalSource[T7], s8: SignalSource[T8]
   )(implicit c: Composition[A, (T1, T2, T3, T4, T5, T6, T7, T8)]): Signal[c.Composed] = {
-    val combinator = (a: A, v1: T1, v2: T2, v3: T3, v4: T4, v5: T5, v6: T6, v7: T7, v8: T8) => c.compose(a, (v1, v2, v3, v4, v5, v6, v7, v8))
-    new SampleCombineSignal9(signal, s1, s2, s3, s4, s5, s6, s7, s8, combinator)
+    val combinator = (arr: JsArray[Any]) => c.compose(arr(0).asInstanceOf[A], (arr(1).asInstanceOf[T1], arr(2).asInstanceOf[T2], arr(3).asInstanceOf[T3], arr(4).asInstanceOf[T4], arr(5).asInstanceOf[T5], arr(6).asInstanceOf[T6], arr(7).asInstanceOf[T7], arr(8).asInstanceOf[T8]))
+    val sampledSignals = JsArray[Signal[Any]](s1.toObservable, s2.toObservable, s3.toObservable, s4.toObservable, s5.toObservable, s6.toObservable, s7.toObservable, s8.toObservable)
+    new SampleCombineSignalN(
+      signal, sampledSignals, combinator
+    )
   }
 
   def sample[T1, T2, T3, T4, T5, T6, T7, T8](
     s1: SignalSource[T1], s2: SignalSource[T2], s3: SignalSource[T3], s4: SignalSource[T4], s5: SignalSource[T5], s6: SignalSource[T6], s7: SignalSource[T7], s8: SignalSource[T8]
   ): Signal[(T1, T2, T3, T4, T5, T6, T7, T8)] = {
-    new SampleCombineSignal9[A, T1, T2, T3, T4, T5, T6, T7, T8, (T1, T2, T3, T4, T5, T6, T7, T8)](signal, s1, s2, s3, s4, s5, s6, s7, s8, (_, v1, v2, v3, v4, v5, v6, v7, v8) => (v1, v2, v3, v4, v5, v6, v7, v8))
+    val combinator = (arr: JsArray[Any]) => (arr(1).asInstanceOf[T1], arr(2).asInstanceOf[T2], arr(3).asInstanceOf[T3], arr(4).asInstanceOf[T4], arr(5).asInstanceOf[T5], arr(6).asInstanceOf[T6], arr(7).asInstanceOf[T7], arr(8).asInstanceOf[T8])
+    val sampledSignals = JsArray[Signal[Any]](s1.toObservable, s2.toObservable, s3.toObservable, s4.toObservable, s5.toObservable, s6.toObservable, s7.toObservable, s8.toObservable)
+    new SampleCombineSignalN[Any, (T1, T2, T3, T4, T5, T6, T7, T8)](
+      signal, sampledSignals, combinator
+    )
   }
 
   // --
diff --git a/src/main/scala/com/raquo/airstream/combine/generated/CombinableStream.scala b/src/main/scala/com/raquo/airstream/combine/generated/CombinableStream.scala
index c5866869..f6b4faee 100644
--- a/src/main/scala/com/raquo/airstream/combine/generated/CombinableStream.scala
+++ b/src/main/scala/com/raquo/airstream/combine/generated/CombinableStream.scala
@@ -1,8 +1,10 @@
 package com.raquo.airstream.combine.generated
 
 import app.tulz.tuplez.Composition
-import com.raquo.airstream.core.EventStream
+import com.raquo.airstream.combine.SampleCombineStreamN
+import com.raquo.airstream.core.{EventStream, Signal}
 import com.raquo.airstream.core.Source.{EventSource, SignalSource}
+import com.raquo.ew.JsArray
 
 // #Warning do not edit this file directly, it is generated by GenerateCombinableStream.scala
 
@@ -23,20 +25,27 @@ class CombinableStream[A](val stream: EventStream[A]) extends AnyVal {
   )(
     combinator: (A, T1) => Out
   ): EventStream[Out] = {
-    new CombineStream2(stream, s1, combinator)
+    StaticStreamCombineOps.combineWithFn(stream, s1)(combinator)
   }
 
   def withCurrentValueOf[T1](
     s1: SignalSource[T1]
   )(implicit c: Composition[A, (T1)]): EventStream[c.Composed] = {
-    val combinator = (a: A, v1: T1) => c.compose(a, (v1))
-    new SampleCombineStream2(stream, s1, combinator)
+    val combinator = (arr: JsArray[Any]) => c.compose(arr(0).asInstanceOf[A], (arr(1).asInstanceOf[T1]))
+    val sampledSignals = JsArray[Signal[Any]](s1.toObservable)
+    new SampleCombineStreamN(
+      stream, sampledSignals, combinator
+    )
   }
 
   def sample[T1](
     s1: SignalSource[T1]
   ): EventStream[(T1)] = {
-    new SampleCombineStream2[A, T1, (T1)](stream, s1, (_, v1) => (v1))
+    val combinator = (arr: JsArray[Any]) => (arr(1).asInstanceOf[T1])
+    val sampledSignals = JsArray[Signal[Any]](s1.toObservable)
+    new SampleCombineStreamN[Any, (T1)](
+      stream, sampledSignals, combinator
+    )
   }
 
   // --
@@ -53,20 +62,27 @@ class CombinableStream[A](val stream: EventStream[A]) extends AnyVal {
   )(
     combinator: (A, T1, T2) => Out
   ): EventStream[Out] = {
-    new CombineStream3(stream, s1, s2, combinator)
+    StaticStreamCombineOps.combineWithFn(stream, s1, s2)(combinator)
   }
 
   def withCurrentValueOf[T1, T2](
     s1: SignalSource[T1], s2: SignalSource[T2]
   )(implicit c: Composition[A, (T1, T2)]): EventStream[c.Composed] = {
-    val combinator = (a: A, v1: T1, v2: T2) => c.compose(a, (v1, v2))
-    new SampleCombineStream3(stream, s1, s2, combinator)
+    val combinator = (arr: JsArray[Any]) => c.compose(arr(0).asInstanceOf[A], (arr(1).asInstanceOf[T1], arr(2).asInstanceOf[T2]))
+    val sampledSignals = JsArray[Signal[Any]](s1.toObservable, s2.toObservable)
+    new SampleCombineStreamN(
+      stream, sampledSignals, combinator
+    )
   }
 
   def sample[T1, T2](
     s1: SignalSource[T1], s2: SignalSource[T2]
   ): EventStream[(T1, T2)] = {
-    new SampleCombineStream3[A, T1, T2, (T1, T2)](stream, s1, s2, (_, v1, v2) => (v1, v2))
+    val combinator = (arr: JsArray[Any]) => (arr(1).asInstanceOf[T1], arr(2).asInstanceOf[T2])
+    val sampledSignals = JsArray[Signal[Any]](s1.toObservable, s2.toObservable)
+    new SampleCombineStreamN[Any, (T1, T2)](
+      stream, sampledSignals, combinator
+    )
   }
 
   // --
@@ -83,20 +99,27 @@ class CombinableStream[A](val stream: EventStream[A]) extends AnyVal {
   )(
     combinator: (A, T1, T2, T3) => Out
   ): EventStream[Out] = {
-    new CombineStream4(stream, s1, s2, s3, combinator)
+    StaticStreamCombineOps.combineWithFn(stream, s1, s2, s3)(combinator)
   }
 
   def withCurrentValueOf[T1, T2, T3](
     s1: SignalSource[T1], s2: SignalSource[T2], s3: SignalSource[T3]
   )(implicit c: Composition[A, (T1, T2, T3)]): EventStream[c.Composed] = {
-    val combinator = (a: A, v1: T1, v2: T2, v3: T3) => c.compose(a, (v1, v2, v3))
-    new SampleCombineStream4(stream, s1, s2, s3, combinator)
+    val combinator = (arr: JsArray[Any]) => c.compose(arr(0).asInstanceOf[A], (arr(1).asInstanceOf[T1], arr(2).asInstanceOf[T2], arr(3).asInstanceOf[T3]))
+    val sampledSignals = JsArray[Signal[Any]](s1.toObservable, s2.toObservable, s3.toObservable)
+    new SampleCombineStreamN(
+      stream, sampledSignals, combinator
+    )
   }
 
   def sample[T1, T2, T3](
     s1: SignalSource[T1], s2: SignalSource[T2], s3: SignalSource[T3]
   ): EventStream[(T1, T2, T3)] = {
-    new SampleCombineStream4[A, T1, T2, T3, (T1, T2, T3)](stream, s1, s2, s3, (_, v1, v2, v3) => (v1, v2, v3))
+    val combinator = (arr: JsArray[Any]) => (arr(1).asInstanceOf[T1], arr(2).asInstanceOf[T2], arr(3).asInstanceOf[T3])
+    val sampledSignals = JsArray[Signal[Any]](s1.toObservable, s2.toObservable, s3.toObservable)
+    new SampleCombineStreamN[Any, (T1, T2, T3)](
+      stream, sampledSignals, combinator
+    )
   }
 
   // --
@@ -113,20 +136,27 @@ class CombinableStream[A](val stream: EventStream[A]) extends AnyVal {
   )(
     combinator: (A, T1, T2, T3, T4) => Out
   ): EventStream[Out] = {
-    new CombineStream5(stream, s1, s2, s3, s4, combinator)
+    StaticStreamCombineOps.combineWithFn(stream, s1, s2, s3, s4)(combinator)
   }
 
   def withCurrentValueOf[T1, T2, T3, T4](
     s1: SignalSource[T1], s2: SignalSource[T2], s3: SignalSource[T3], s4: SignalSource[T4]
   )(implicit c: Composition[A, (T1, T2, T3, T4)]): EventStream[c.Composed] = {
-    val combinator = (a: A, v1: T1, v2: T2, v3: T3, v4: T4) => c.compose(a, (v1, v2, v3, v4))
-    new SampleCombineStream5(stream, s1, s2, s3, s4, combinator)
+    val combinator = (arr: JsArray[Any]) => c.compose(arr(0).asInstanceOf[A], (arr(1).asInstanceOf[T1], arr(2).asInstanceOf[T2], arr(3).asInstanceOf[T3], arr(4).asInstanceOf[T4]))
+    val sampledSignals = JsArray[Signal[Any]](s1.toObservable, s2.toObservable, s3.toObservable, s4.toObservable)
+    new SampleCombineStreamN(
+      stream, sampledSignals, combinator
+    )
   }
 
   def sample[T1, T2, T3, T4](
     s1: SignalSource[T1], s2: SignalSource[T2], s3: SignalSource[T3], s4: SignalSource[T4]
   ): EventStream[(T1, T2, T3, T4)] = {
-    new SampleCombineStream5[A, T1, T2, T3, T4, (T1, T2, T3, T4)](stream, s1, s2, s3, s4, (_, v1, v2, v3, v4) => (v1, v2, v3, v4))
+    val combinator = (arr: JsArray[Any]) => (arr(1).asInstanceOf[T1], arr(2).asInstanceOf[T2], arr(3).asInstanceOf[T3], arr(4).asInstanceOf[T4])
+    val sampledSignals = JsArray[Signal[Any]](s1.toObservable, s2.toObservable, s3.toObservable, s4.toObservable)
+    new SampleCombineStreamN[Any, (T1, T2, T3, T4)](
+      stream, sampledSignals, combinator
+    )
   }
 
   // --
@@ -143,20 +173,27 @@ class CombinableStream[A](val stream: EventStream[A]) extends AnyVal {
   )(
     combinator: (A, T1, T2, T3, T4, T5) => Out
   ): EventStream[Out] = {
-    new CombineStream6(stream, s1, s2, s3, s4, s5, combinator)
+    StaticStreamCombineOps.combineWithFn(stream, s1, s2, s3, s4, s5)(combinator)
   }
 
   def withCurrentValueOf[T1, T2, T3, T4, T5](
     s1: SignalSource[T1], s2: SignalSource[T2], s3: SignalSource[T3], s4: SignalSource[T4], s5: SignalSource[T5]
   )(implicit c: Composition[A, (T1, T2, T3, T4, T5)]): EventStream[c.Composed] = {
-    val combinator = (a: A, v1: T1, v2: T2, v3: T3, v4: T4, v5: T5) => c.compose(a, (v1, v2, v3, v4, v5))
-    new SampleCombineStream6(stream, s1, s2, s3, s4, s5, combinator)
+    val combinator = (arr: JsArray[Any]) => c.compose(arr(0).asInstanceOf[A], (arr(1).asInstanceOf[T1], arr(2).asInstanceOf[T2], arr(3).asInstanceOf[T3], arr(4).asInstanceOf[T4], arr(5).asInstanceOf[T5]))
+    val sampledSignals = JsArray[Signal[Any]](s1.toObservable, s2.toObservable, s3.toObservable, s4.toObservable, s5.toObservable)
+    new SampleCombineStreamN(
+      stream, sampledSignals, combinator
+    )
   }
 
   def sample[T1, T2, T3, T4, T5](
     s1: SignalSource[T1], s2: SignalSource[T2], s3: SignalSource[T3], s4: SignalSource[T4], s5: SignalSource[T5]
   ): EventStream[(T1, T2, T3, T4, T5)] = {
-    new SampleCombineStream6[A, T1, T2, T3, T4, T5, (T1, T2, T3, T4, T5)](stream, s1, s2, s3, s4, s5, (_, v1, v2, v3, v4, v5) => (v1, v2, v3, v4, v5))
+    val combinator = (arr: JsArray[Any]) => (arr(1).asInstanceOf[T1], arr(2).asInstanceOf[T2], arr(3).asInstanceOf[T3], arr(4).asInstanceOf[T4], arr(5).asInstanceOf[T5])
+    val sampledSignals = JsArray[Signal[Any]](s1.toObservable, s2.toObservable, s3.toObservable, s4.toObservable, s5.toObservable)
+    new SampleCombineStreamN[Any, (T1, T2, T3, T4, T5)](
+      stream, sampledSignals, combinator
+    )
   }
 
   // --
@@ -173,20 +210,27 @@ class CombinableStream[A](val stream: EventStream[A]) extends AnyVal {
   )(
     combinator: (A, T1, T2, T3, T4, T5, T6) => Out
   ): EventStream[Out] = {
-    new CombineStream7(stream, s1, s2, s3, s4, s5, s6, combinator)
+    StaticStreamCombineOps.combineWithFn(stream, s1, s2, s3, s4, s5, s6)(combinator)
   }
 
   def withCurrentValueOf[T1, T2, T3, T4, T5, T6](
     s1: SignalSource[T1], s2: SignalSource[T2], s3: SignalSource[T3], s4: SignalSource[T4], s5: SignalSource[T5], s6: SignalSource[T6]
   )(implicit c: Composition[A, (T1, T2, T3, T4, T5, T6)]): EventStream[c.Composed] = {
-    val combinator = (a: A, v1: T1, v2: T2, v3: T3, v4: T4, v5: T5, v6: T6) => c.compose(a, (v1, v2, v3, v4, v5, v6))
-    new SampleCombineStream7(stream, s1, s2, s3, s4, s5, s6, combinator)
+    val combinator = (arr: JsArray[Any]) => c.compose(arr(0).asInstanceOf[A], (arr(1).asInstanceOf[T1], arr(2).asInstanceOf[T2], arr(3).asInstanceOf[T3], arr(4).asInstanceOf[T4], arr(5).asInstanceOf[T5], arr(6).asInstanceOf[T6]))
+    val sampledSignals = JsArray[Signal[Any]](s1.toObservable, s2.toObservable, s3.toObservable, s4.toObservable, s5.toObservable, s6.toObservable)
+    new SampleCombineStreamN(
+      stream, sampledSignals, combinator
+    )
   }
 
   def sample[T1, T2, T3, T4, T5, T6](
     s1: SignalSource[T1], s2: SignalSource[T2], s3: SignalSource[T3], s4: SignalSource[T4], s5: SignalSource[T5], s6: SignalSource[T6]
   ): EventStream[(T1, T2, T3, T4, T5, T6)] = {
-    new SampleCombineStream7[A, T1, T2, T3, T4, T5, T6, (T1, T2, T3, T4, T5, T6)](stream, s1, s2, s3, s4, s5, s6, (_, v1, v2, v3, v4, v5, v6) => (v1, v2, v3, v4, v5, v6))
+    val combinator = (arr: JsArray[Any]) => (arr(1).asInstanceOf[T1], arr(2).asInstanceOf[T2], arr(3).asInstanceOf[T3], arr(4).asInstanceOf[T4], arr(5).asInstanceOf[T5], arr(6).asInstanceOf[T6])
+    val sampledSignals = JsArray[Signal[Any]](s1.toObservable, s2.toObservable, s3.toObservable, s4.toObservable, s5.toObservable, s6.toObservable)
+    new SampleCombineStreamN[Any, (T1, T2, T3, T4, T5, T6)](
+      stream, sampledSignals, combinator
+    )
   }
 
   // --
@@ -203,20 +247,27 @@ class CombinableStream[A](val stream: EventStream[A]) extends AnyVal {
   )(
     combinator: (A, T1, T2, T3, T4, T5, T6, T7) => Out
   ): EventStream[Out] = {
-    new CombineStream8(stream, s1, s2, s3, s4, s5, s6, s7, combinator)
+    StaticStreamCombineOps.combineWithFn(stream, s1, s2, s3, s4, s5, s6, s7)(combinator)
   }
 
   def withCurrentValueOf[T1, T2, T3, T4, T5, T6, T7](
     s1: SignalSource[T1], s2: SignalSource[T2], s3: SignalSource[T3], s4: SignalSource[T4], s5: SignalSource[T5], s6: SignalSource[T6], s7: SignalSource[T7]
   )(implicit c: Composition[A, (T1, T2, T3, T4, T5, T6, T7)]): EventStream[c.Composed] = {
-    val combinator = (a: A, v1: T1, v2: T2, v3: T3, v4: T4, v5: T5, v6: T6, v7: T7) => c.compose(a, (v1, v2, v3, v4, v5, v6, v7))
-    new SampleCombineStream8(stream, s1, s2, s3, s4, s5, s6, s7, combinator)
+    val combinator = (arr: JsArray[Any]) => c.compose(arr(0).asInstanceOf[A], (arr(1).asInstanceOf[T1], arr(2).asInstanceOf[T2], arr(3).asInstanceOf[T3], arr(4).asInstanceOf[T4], arr(5).asInstanceOf[T5], arr(6).asInstanceOf[T6], arr(7).asInstanceOf[T7]))
+    val sampledSignals = JsArray[Signal[Any]](s1.toObservable, s2.toObservable, s3.toObservable, s4.toObservable, s5.toObservable, s6.toObservable, s7.toObservable)
+    new SampleCombineStreamN(
+      stream, sampledSignals, combinator
+    )
   }
 
   def sample[T1, T2, T3, T4, T5, T6, T7](
     s1: SignalSource[T1], s2: SignalSource[T2], s3: SignalSource[T3], s4: SignalSource[T4], s5: SignalSource[T5], s6: SignalSource[T6], s7: SignalSource[T7]
   ): EventStream[(T1, T2, T3, T4, T5, T6, T7)] = {
-    new SampleCombineStream8[A, T1, T2, T3, T4, T5, T6, T7, (T1, T2, T3, T4, T5, T6, T7)](stream, s1, s2, s3, s4, s5, s6, s7, (_, v1, v2, v3, v4, v5, v6, v7) => (v1, v2, v3, v4, v5, v6, v7))
+    val combinator = (arr: JsArray[Any]) => (arr(1).asInstanceOf[T1], arr(2).asInstanceOf[T2], arr(3).asInstanceOf[T3], arr(4).asInstanceOf[T4], arr(5).asInstanceOf[T5], arr(6).asInstanceOf[T6], arr(7).asInstanceOf[T7])
+    val sampledSignals = JsArray[Signal[Any]](s1.toObservable, s2.toObservable, s3.toObservable, s4.toObservable, s5.toObservable, s6.toObservable, s7.toObservable)
+    new SampleCombineStreamN[Any, (T1, T2, T3, T4, T5, T6, T7)](
+      stream, sampledSignals, combinator
+    )
   }
 
   // --
@@ -233,20 +284,27 @@ class CombinableStream[A](val stream: EventStream[A]) extends AnyVal {
   )(
     combinator: (A, T1, T2, T3, T4, T5, T6, T7, T8) => Out
   ): EventStream[Out] = {
-    new CombineStream9(stream, s1, s2, s3, s4, s5, s6, s7, s8, combinator)
+    StaticStreamCombineOps.combineWithFn(stream, s1, s2, s3, s4, s5, s6, s7, s8)(combinator)
   }
 
   def withCurrentValueOf[T1, T2, T3, T4, T5, T6, T7, T8](
     s1: SignalSource[T1], s2: SignalSource[T2], s3: SignalSource[T3], s4: SignalSource[T4], s5: SignalSource[T5], s6: SignalSource[T6], s7: SignalSource[T7], s8: SignalSource[T8]
   )(implicit c: Composition[A, (T1, T2, T3, T4, T5, T6, T7, T8)]): EventStream[c.Composed] = {
-    val combinator = (a: A, v1: T1, v2: T2, v3: T3, v4: T4, v5: T5, v6: T6, v7: T7, v8: T8) => c.compose(a, (v1, v2, v3, v4, v5, v6, v7, v8))
-    new SampleCombineStream9(stream, s1, s2, s3, s4, s5, s6, s7, s8, combinator)
+    val combinator = (arr: JsArray[Any]) => c.compose(arr(0).asInstanceOf[A], (arr(1).asInstanceOf[T1], arr(2).asInstanceOf[T2], arr(3).asInstanceOf[T3], arr(4).asInstanceOf[T4], arr(5).asInstanceOf[T5], arr(6).asInstanceOf[T6], arr(7).asInstanceOf[T7], arr(8).asInstanceOf[T8]))
+    val sampledSignals = JsArray[Signal[Any]](s1.toObservable, s2.toObservable, s3.toObservable, s4.toObservable, s5.toObservable, s6.toObservable, s7.toObservable, s8.toObservable)
+    new SampleCombineStreamN(
+      stream, sampledSignals, combinator
+    )
   }
 
   def sample[T1, T2, T3, T4, T5, T6, T7, T8](
     s1: SignalSource[T1], s2: SignalSource[T2], s3: SignalSource[T3], s4: SignalSource[T4], s5: SignalSource[T5], s6: SignalSource[T6], s7: SignalSource[T7], s8: SignalSource[T8]
   ): EventStream[(T1, T2, T3, T4, T5, T6, T7, T8)] = {
-    new SampleCombineStream9[A, T1, T2, T3, T4, T5, T6, T7, T8, (T1, T2, T3, T4, T5, T6, T7, T8)](stream, s1, s2, s3, s4, s5, s6, s7, s8, (_, v1, v2, v3, v4, v5, v6, v7, v8) => (v1, v2, v3, v4, v5, v6, v7, v8))
+    val combinator = (arr: JsArray[Any]) => (arr(1).asInstanceOf[T1], arr(2).asInstanceOf[T2], arr(3).asInstanceOf[T3], arr(4).asInstanceOf[T4], arr(5).asInstanceOf[T5], arr(6).asInstanceOf[T6], arr(7).asInstanceOf[T7], arr(8).asInstanceOf[T8])
+    val sampledSignals = JsArray[Signal[Any]](s1.toObservable, s2.toObservable, s3.toObservable, s4.toObservable, s5.toObservable, s6.toObservable, s7.toObservable, s8.toObservable)
+    new SampleCombineStreamN[Any, (T1, T2, T3, T4, T5, T6, T7, T8)](
+      stream, sampledSignals, combinator
+    )
   }
 
   // --
diff --git a/src/main/scala/com/raquo/airstream/combine/generated/CombineSignals.scala b/src/main/scala/com/raquo/airstream/combine/generated/CombineSignals.scala
deleted file mode 100644
index d87f9a2a..00000000
--- a/src/main/scala/com/raquo/airstream/combine/generated/CombineSignals.scala
+++ /dev/null
@@ -1,170 +0,0 @@
-package com.raquo.airstream.combine.generated
-
-import com.raquo.airstream.combine.CombineSignalN
-import com.raquo.airstream.core.Source.SignalSource
-
-// #Warning do not edit this file directly, it is generated by GenerateCombineSignals.scala
-
-// These are implementations of CombineSignalN used for Signal's `combine` and `combineWith` methods
-
-/** @param combinator Must not throw! */
-class CombineSignal2[T1, T2, Out](
-  parent1: SignalSource[T1],
-  parent2: SignalSource[T2],
-  combinator: (T1, T2) => Out
-) extends CombineSignalN[Any, Out](
-  parents = parent1.toObservable :: parent2.toObservable :: Nil,
-  combinator = seq => combinator(
-    seq(0).asInstanceOf[T1],
-    seq(1).asInstanceOf[T2],
-  )
-)
-
-/** @param combinator Must not throw! */
-class CombineSignal3[T1, T2, T3, Out](
-  parent1: SignalSource[T1],
-  parent2: SignalSource[T2],
-  parent3: SignalSource[T3],
-  combinator: (T1, T2, T3) => Out
-) extends CombineSignalN[Any, Out](
-  parents = parent1.toObservable :: parent2.toObservable :: parent3.toObservable :: Nil,
-  combinator = seq => combinator(
-    seq(0).asInstanceOf[T1],
-    seq(1).asInstanceOf[T2],
-    seq(2).asInstanceOf[T3],
-  )
-)
-
-/** @param combinator Must not throw! */
-class CombineSignal4[T1, T2, T3, T4, Out](
-  parent1: SignalSource[T1],
-  parent2: SignalSource[T2],
-  parent3: SignalSource[T3],
-  parent4: SignalSource[T4],
-  combinator: (T1, T2, T3, T4) => Out
-) extends CombineSignalN[Any, Out](
-  parents = parent1.toObservable :: parent2.toObservable :: parent3.toObservable :: parent4.toObservable :: Nil,
-  combinator = seq => combinator(
-    seq(0).asInstanceOf[T1],
-    seq(1).asInstanceOf[T2],
-    seq(2).asInstanceOf[T3],
-    seq(3).asInstanceOf[T4],
-  )
-)
-
-/** @param combinator Must not throw! */
-class CombineSignal5[T1, T2, T3, T4, T5, Out](
-  parent1: SignalSource[T1],
-  parent2: SignalSource[T2],
-  parent3: SignalSource[T3],
-  parent4: SignalSource[T4],
-  parent5: SignalSource[T5],
-  combinator: (T1, T2, T3, T4, T5) => Out
-) extends CombineSignalN[Any, Out](
-  parents = parent1.toObservable :: parent2.toObservable :: parent3.toObservable :: parent4.toObservable :: parent5.toObservable :: Nil,
-  combinator = seq => combinator(
-    seq(0).asInstanceOf[T1],
-    seq(1).asInstanceOf[T2],
-    seq(2).asInstanceOf[T3],
-    seq(3).asInstanceOf[T4],
-    seq(4).asInstanceOf[T5],
-  )
-)
-
-/** @param combinator Must not throw! */
-class CombineSignal6[T1, T2, T3, T4, T5, T6, Out](
-  parent1: SignalSource[T1],
-  parent2: SignalSource[T2],
-  parent3: SignalSource[T3],
-  parent4: SignalSource[T4],
-  parent5: SignalSource[T5],
-  parent6: SignalSource[T6],
-  combinator: (T1, T2, T3, T4, T5, T6) => Out
-) extends CombineSignalN[Any, Out](
-  parents = parent1.toObservable :: parent2.toObservable :: parent3.toObservable :: parent4.toObservable :: parent5.toObservable :: parent6.toObservable :: Nil,
-  combinator = seq => combinator(
-    seq(0).asInstanceOf[T1],
-    seq(1).asInstanceOf[T2],
-    seq(2).asInstanceOf[T3],
-    seq(3).asInstanceOf[T4],
-    seq(4).asInstanceOf[T5],
-    seq(5).asInstanceOf[T6],
-  )
-)
-
-/** @param combinator Must not throw! */
-class CombineSignal7[T1, T2, T3, T4, T5, T6, T7, Out](
-  parent1: SignalSource[T1],
-  parent2: SignalSource[T2],
-  parent3: SignalSource[T3],
-  parent4: SignalSource[T4],
-  parent5: SignalSource[T5],
-  parent6: SignalSource[T6],
-  parent7: SignalSource[T7],
-  combinator: (T1, T2, T3, T4, T5, T6, T7) => Out
-) extends CombineSignalN[Any, Out](
-  parents = parent1.toObservable :: parent2.toObservable :: parent3.toObservable :: parent4.toObservable :: parent5.toObservable :: parent6.toObservable :: parent7.toObservable :: Nil,
-  combinator = seq => combinator(
-    seq(0).asInstanceOf[T1],
-    seq(1).asInstanceOf[T2],
-    seq(2).asInstanceOf[T3],
-    seq(3).asInstanceOf[T4],
-    seq(4).asInstanceOf[T5],
-    seq(5).asInstanceOf[T6],
-    seq(6).asInstanceOf[T7],
-  )
-)
-
-/** @param combinator Must not throw! */
-class CombineSignal8[T1, T2, T3, T4, T5, T6, T7, T8, Out](
-  parent1: SignalSource[T1],
-  parent2: SignalSource[T2],
-  parent3: SignalSource[T3],
-  parent4: SignalSource[T4],
-  parent5: SignalSource[T5],
-  parent6: SignalSource[T6],
-  parent7: SignalSource[T7],
-  parent8: SignalSource[T8],
-  combinator: (T1, T2, T3, T4, T5, T6, T7, T8) => Out
-) extends CombineSignalN[Any, Out](
-  parents = parent1.toObservable :: parent2.toObservable :: parent3.toObservable :: parent4.toObservable :: parent5.toObservable :: parent6.toObservable :: parent7.toObservable :: parent8.toObservable :: Nil,
-  combinator = seq => combinator(
-    seq(0).asInstanceOf[T1],
-    seq(1).asInstanceOf[T2],
-    seq(2).asInstanceOf[T3],
-    seq(3).asInstanceOf[T4],
-    seq(4).asInstanceOf[T5],
-    seq(5).asInstanceOf[T6],
-    seq(6).asInstanceOf[T7],
-    seq(7).asInstanceOf[T8],
-  )
-)
-
-/** @param combinator Must not throw! */
-class CombineSignal9[T1, T2, T3, T4, T5, T6, T7, T8, T9, Out](
-  parent1: SignalSource[T1],
-  parent2: SignalSource[T2],
-  parent3: SignalSource[T3],
-  parent4: SignalSource[T4],
-  parent5: SignalSource[T5],
-  parent6: SignalSource[T6],
-  parent7: SignalSource[T7],
-  parent8: SignalSource[T8],
-  parent9: SignalSource[T9],
-  combinator: (T1, T2, T3, T4, T5, T6, T7, T8, T9) => Out
-) extends CombineSignalN[Any, Out](
-  parents = parent1.toObservable :: parent2.toObservable :: parent3.toObservable :: parent4.toObservable :: parent5.toObservable :: parent6.toObservable :: parent7.toObservable :: parent8.toObservable :: parent9.toObservable :: Nil,
-  combinator = seq => combinator(
-    seq(0).asInstanceOf[T1],
-    seq(1).asInstanceOf[T2],
-    seq(2).asInstanceOf[T3],
-    seq(3).asInstanceOf[T4],
-    seq(4).asInstanceOf[T5],
-    seq(5).asInstanceOf[T6],
-    seq(6).asInstanceOf[T7],
-    seq(7).asInstanceOf[T8],
-    seq(8).asInstanceOf[T9],
-  )
-)
-
-
diff --git a/src/main/scala/com/raquo/airstream/combine/generated/CombineStreams.scala b/src/main/scala/com/raquo/airstream/combine/generated/CombineStreams.scala
deleted file mode 100644
index 1d7485a6..00000000
--- a/src/main/scala/com/raquo/airstream/combine/generated/CombineStreams.scala
+++ /dev/null
@@ -1,169 +0,0 @@
-package com.raquo.airstream.combine.generated
-
-import com.raquo.airstream.combine.CombineStreamN
-import com.raquo.airstream.core.Source.EventSource
-
-// #Warning do not edit this file directly, it is generated by GenerateCombineStreams.scala
-
-// These are implementations of CombineStreamN used for EventStream's `combine` and `combineWith` methods
-
-/** @param combinator Must not throw! */
-class CombineStream2[T1, T2, Out](
-  parent1: EventSource[T1],
-  parent2: EventSource[T2],
-  combinator: (T1, T2) => Out
-) extends CombineStreamN[Any, Out](
-  parents = parent1.toObservable :: parent2.toObservable :: Nil,
-  combinator = seq => combinator(
-    seq(0).asInstanceOf[T1],
-    seq(1).asInstanceOf[T2],
-  )
-)
-
-/** @param combinator Must not throw! */
-class CombineStream3[T1, T2, T3, Out](
-  parent1: EventSource[T1],
-  parent2: EventSource[T2],
-  parent3: EventSource[T3],
-  combinator: (T1, T2, T3) => Out
-) extends CombineStreamN[Any, Out](
-  parents = parent1.toObservable :: parent2.toObservable :: parent3.toObservable :: Nil,
-  combinator = seq => combinator(
-    seq(0).asInstanceOf[T1],
-    seq(1).asInstanceOf[T2],
-    seq(2).asInstanceOf[T3],
-  )
-)
-
-/** @param combinator Must not throw! */
-class CombineStream4[T1, T2, T3, T4, Out](
-  parent1: EventSource[T1],
-  parent2: EventSource[T2],
-  parent3: EventSource[T3],
-  parent4: EventSource[T4],
-  combinator: (T1, T2, T3, T4) => Out
-) extends CombineStreamN[Any, Out](
-  parents = parent1.toObservable :: parent2.toObservable :: parent3.toObservable :: parent4.toObservable :: Nil,
-  combinator = seq => combinator(
-    seq(0).asInstanceOf[T1],
-    seq(1).asInstanceOf[T2],
-    seq(2).asInstanceOf[T3],
-    seq(3).asInstanceOf[T4],
-  )
-)
-
-/** @param combinator Must not throw! */
-class CombineStream5[T1, T2, T3, T4, T5, Out](
-  parent1: EventSource[T1],
-  parent2: EventSource[T2],
-  parent3: EventSource[T3],
-  parent4: EventSource[T4],
-  parent5: EventSource[T5],
-  combinator: (T1, T2, T3, T4, T5) => Out
-) extends CombineStreamN[Any, Out](
-  parents = parent1.toObservable :: parent2.toObservable :: parent3.toObservable :: parent4.toObservable :: parent5.toObservable :: Nil,
-  combinator = seq => combinator(
-    seq(0).asInstanceOf[T1],
-    seq(1).asInstanceOf[T2],
-    seq(2).asInstanceOf[T3],
-    seq(3).asInstanceOf[T4],
-    seq(4).asInstanceOf[T5],
-  )
-)
-
-/** @param combinator Must not throw! */
-class CombineStream6[T1, T2, T3, T4, T5, T6, Out](
-  parent1: EventSource[T1],
-  parent2: EventSource[T2],
-  parent3: EventSource[T3],
-  parent4: EventSource[T4],
-  parent5: EventSource[T5],
-  parent6: EventSource[T6],
-  combinator: (T1, T2, T3, T4, T5, T6) => Out
-) extends CombineStreamN[Any, Out](
-  parents = parent1.toObservable :: parent2.toObservable :: parent3.toObservable :: parent4.toObservable :: parent5.toObservable :: parent6.toObservable :: Nil,
-  combinator = seq => combinator(
-    seq(0).asInstanceOf[T1],
-    seq(1).asInstanceOf[T2],
-    seq(2).asInstanceOf[T3],
-    seq(3).asInstanceOf[T4],
-    seq(4).asInstanceOf[T5],
-    seq(5).asInstanceOf[T6],
-  )
-)
-
-/** @param combinator Must not throw! */
-class CombineStream7[T1, T2, T3, T4, T5, T6, T7, Out](
-  parent1: EventSource[T1],
-  parent2: EventSource[T2],
-  parent3: EventSource[T3],
-  parent4: EventSource[T4],
-  parent5: EventSource[T5],
-  parent6: EventSource[T6],
-  parent7: EventSource[T7],
-  combinator: (T1, T2, T3, T4, T5, T6, T7) => Out
-) extends CombineStreamN[Any, Out](
-  parents = parent1.toObservable :: parent2.toObservable :: parent3.toObservable :: parent4.toObservable :: parent5.toObservable :: parent6.toObservable :: parent7.toObservable :: Nil,
-  combinator = seq => combinator(
-    seq(0).asInstanceOf[T1],
-    seq(1).asInstanceOf[T2],
-    seq(2).asInstanceOf[T3],
-    seq(3).asInstanceOf[T4],
-    seq(4).asInstanceOf[T5],
-    seq(5).asInstanceOf[T6],
-    seq(6).asInstanceOf[T7],
-  )
-)
-
-/** @param combinator Must not throw! */
-class CombineStream8[T1, T2, T3, T4, T5, T6, T7, T8, Out](
-  parent1: EventSource[T1],
-  parent2: EventSource[T2],
-  parent3: EventSource[T3],
-  parent4: EventSource[T4],
-  parent5: EventSource[T5],
-  parent6: EventSource[T6],
-  parent7: EventSource[T7],
-  parent8: EventSource[T8],
-  combinator: (T1, T2, T3, T4, T5, T6, T7, T8) => Out
-) extends CombineStreamN[Any, Out](
-  parents = parent1.toObservable :: parent2.toObservable :: parent3.toObservable :: parent4.toObservable :: parent5.toObservable :: parent6.toObservable :: parent7.toObservable :: parent8.toObservable :: Nil,
-  combinator = seq => combinator(
-    seq(0).asInstanceOf[T1],
-    seq(1).asInstanceOf[T2],
-    seq(2).asInstanceOf[T3],
-    seq(3).asInstanceOf[T4],
-    seq(4).asInstanceOf[T5],
-    seq(5).asInstanceOf[T6],
-    seq(6).asInstanceOf[T7],
-    seq(7).asInstanceOf[T8],
-  )
-)
-
-/** @param combinator Must not throw! */
-class CombineStream9[T1, T2, T3, T4, T5, T6, T7, T8, T9, Out](
-  parent1: EventSource[T1],
-  parent2: EventSource[T2],
-  parent3: EventSource[T3],
-  parent4: EventSource[T4],
-  parent5: EventSource[T5],
-  parent6: EventSource[T6],
-  parent7: EventSource[T7],
-  parent8: EventSource[T8],
-  parent9: EventSource[T9],
-  combinator: (T1, T2, T3, T4, T5, T6, T7, T8, T9) => Out
-) extends CombineStreamN[Any, Out](
-  parents = parent1.toObservable :: parent2.toObservable :: parent3.toObservable :: parent4.toObservable :: parent5.toObservable :: parent6.toObservable :: parent7.toObservable :: parent8.toObservable :: parent9.toObservable :: Nil,
-  combinator = seq => combinator(
-    seq(0).asInstanceOf[T1],
-    seq(1).asInstanceOf[T2],
-    seq(2).asInstanceOf[T3],
-    seq(3).asInstanceOf[T4],
-    seq(4).asInstanceOf[T5],
-    seq(5).asInstanceOf[T6],
-    seq(6).asInstanceOf[T7],
-    seq(7).asInstanceOf[T8],
-    seq(8).asInstanceOf[T9],
-  )
-)
-
diff --git a/src/main/scala/com/raquo/airstream/combine/generated/SampleCombineSignals.scala b/src/main/scala/com/raquo/airstream/combine/generated/SampleCombineSignals.scala
deleted file mode 100644
index 1b3640d0..00000000
--- a/src/main/scala/com/raquo/airstream/combine/generated/SampleCombineSignals.scala
+++ /dev/null
@@ -1,179 +0,0 @@
-package com.raquo.airstream.combine.generated
-
-import com.raquo.airstream.combine.SampleCombineSignalN
-import com.raquo.airstream.core.Signal
-import com.raquo.airstream.core.Source.SignalSource
-
-// #Warning do not edit this file directly, it is generated by GenerateSampleCombineSignals.scala
-
-// These are implementations of SampleCombineSignalN used for Signal's `withCurrentValueOf` and `sample` methods
-
-/** @param combinator Must not throw! */
-class SampleCombineSignal2[T0, T1, Out](
-  samplingSignal: Signal[T0],
-  sampledSignal1: SignalSource[T1],
-  combinator: (T0, T1) => Out
-) extends SampleCombineSignalN[Any, Out](
-  samplingSignal = samplingSignal,
-  sampledSignals = sampledSignal1.toObservable :: Nil,
-  combinator = seq => combinator(
-    seq(0).asInstanceOf[T0],
-    seq(1).asInstanceOf[T1],
-  )
-)
-
-/** @param combinator Must not throw! */
-class SampleCombineSignal3[T0, T1, T2, Out](
-  samplingSignal: Signal[T0],
-  sampledSignal1: SignalSource[T1],
-  sampledSignal2: SignalSource[T2],
-  combinator: (T0, T1, T2) => Out
-) extends SampleCombineSignalN[Any, Out](
-  samplingSignal = samplingSignal,
-  sampledSignals = sampledSignal1.toObservable :: sampledSignal2.toObservable :: Nil,
-  combinator = seq => combinator(
-    seq(0).asInstanceOf[T0],
-    seq(1).asInstanceOf[T1],
-    seq(2).asInstanceOf[T2],
-  )
-)
-
-/** @param combinator Must not throw! */
-class SampleCombineSignal4[T0, T1, T2, T3, Out](
-  samplingSignal: Signal[T0],
-  sampledSignal1: SignalSource[T1],
-  sampledSignal2: SignalSource[T2],
-  sampledSignal3: SignalSource[T3],
-  combinator: (T0, T1, T2, T3) => Out
-) extends SampleCombineSignalN[Any, Out](
-  samplingSignal = samplingSignal,
-  sampledSignals = sampledSignal1.toObservable :: sampledSignal2.toObservable :: sampledSignal3.toObservable :: Nil,
-  combinator = seq => combinator(
-    seq(0).asInstanceOf[T0],
-    seq(1).asInstanceOf[T1],
-    seq(2).asInstanceOf[T2],
-    seq(3).asInstanceOf[T3],
-  )
-)
-
-/** @param combinator Must not throw! */
-class SampleCombineSignal5[T0, T1, T2, T3, T4, Out](
-  samplingSignal: Signal[T0],
-  sampledSignal1: SignalSource[T1],
-  sampledSignal2: SignalSource[T2],
-  sampledSignal3: SignalSource[T3],
-  sampledSignal4: SignalSource[T4],
-  combinator: (T0, T1, T2, T3, T4) => Out
-) extends SampleCombineSignalN[Any, Out](
-  samplingSignal = samplingSignal,
-  sampledSignals = sampledSignal1.toObservable :: sampledSignal2.toObservable :: sampledSignal3.toObservable :: sampledSignal4.toObservable :: Nil,
-  combinator = seq => combinator(
-    seq(0).asInstanceOf[T0],
-    seq(1).asInstanceOf[T1],
-    seq(2).asInstanceOf[T2],
-    seq(3).asInstanceOf[T3],
-    seq(4).asInstanceOf[T4],
-  )
-)
-
-/** @param combinator Must not throw! */
-class SampleCombineSignal6[T0, T1, T2, T3, T4, T5, Out](
-  samplingSignal: Signal[T0],
-  sampledSignal1: SignalSource[T1],
-  sampledSignal2: SignalSource[T2],
-  sampledSignal3: SignalSource[T3],
-  sampledSignal4: SignalSource[T4],
-  sampledSignal5: SignalSource[T5],
-  combinator: (T0, T1, T2, T3, T4, T5) => Out
-) extends SampleCombineSignalN[Any, Out](
-  samplingSignal = samplingSignal,
-  sampledSignals = sampledSignal1.toObservable :: sampledSignal2.toObservable :: sampledSignal3.toObservable :: sampledSignal4.toObservable :: sampledSignal5.toObservable :: Nil,
-  combinator = seq => combinator(
-    seq(0).asInstanceOf[T0],
-    seq(1).asInstanceOf[T1],
-    seq(2).asInstanceOf[T2],
-    seq(3).asInstanceOf[T3],
-    seq(4).asInstanceOf[T4],
-    seq(5).asInstanceOf[T5],
-  )
-)
-
-/** @param combinator Must not throw! */
-class SampleCombineSignal7[T0, T1, T2, T3, T4, T5, T6, Out](
-  samplingSignal: Signal[T0],
-  sampledSignal1: SignalSource[T1],
-  sampledSignal2: SignalSource[T2],
-  sampledSignal3: SignalSource[T3],
-  sampledSignal4: SignalSource[T4],
-  sampledSignal5: SignalSource[T5],
-  sampledSignal6: SignalSource[T6],
-  combinator: (T0, T1, T2, T3, T4, T5, T6) => Out
-) extends SampleCombineSignalN[Any, Out](
-  samplingSignal = samplingSignal,
-  sampledSignals = sampledSignal1.toObservable :: sampledSignal2.toObservable :: sampledSignal3.toObservable :: sampledSignal4.toObservable :: sampledSignal5.toObservable :: sampledSignal6.toObservable :: Nil,
-  combinator = seq => combinator(
-    seq(0).asInstanceOf[T0],
-    seq(1).asInstanceOf[T1],
-    seq(2).asInstanceOf[T2],
-    seq(3).asInstanceOf[T3],
-    seq(4).asInstanceOf[T4],
-    seq(5).asInstanceOf[T5],
-    seq(6).asInstanceOf[T6],
-  )
-)
-
-/** @param combinator Must not throw! */
-class SampleCombineSignal8[T0, T1, T2, T3, T4, T5, T6, T7, Out](
-  samplingSignal: Signal[T0],
-  sampledSignal1: SignalSource[T1],
-  sampledSignal2: SignalSource[T2],
-  sampledSignal3: SignalSource[T3],
-  sampledSignal4: SignalSource[T4],
-  sampledSignal5: SignalSource[T5],
-  sampledSignal6: SignalSource[T6],
-  sampledSignal7: SignalSource[T7],
-  combinator: (T0, T1, T2, T3, T4, T5, T6, T7) => Out
-) extends SampleCombineSignalN[Any, Out](
-  samplingSignal = samplingSignal,
-  sampledSignals = sampledSignal1.toObservable :: sampledSignal2.toObservable :: sampledSignal3.toObservable :: sampledSignal4.toObservable :: sampledSignal5.toObservable :: sampledSignal6.toObservable :: sampledSignal7.toObservable :: Nil,
-  combinator = seq => combinator(
-    seq(0).asInstanceOf[T0],
-    seq(1).asInstanceOf[T1],
-    seq(2).asInstanceOf[T2],
-    seq(3).asInstanceOf[T3],
-    seq(4).asInstanceOf[T4],
-    seq(5).asInstanceOf[T5],
-    seq(6).asInstanceOf[T6],
-    seq(7).asInstanceOf[T7],
-  )
-)
-
-/** @param combinator Must not throw! */
-class SampleCombineSignal9[T0, T1, T2, T3, T4, T5, T6, T7, T8, Out](
-  samplingSignal: Signal[T0],
-  sampledSignal1: SignalSource[T1],
-  sampledSignal2: SignalSource[T2],
-  sampledSignal3: SignalSource[T3],
-  sampledSignal4: SignalSource[T4],
-  sampledSignal5: SignalSource[T5],
-  sampledSignal6: SignalSource[T6],
-  sampledSignal7: SignalSource[T7],
-  sampledSignal8: SignalSource[T8],
-  combinator: (T0, T1, T2, T3, T4, T5, T6, T7, T8) => Out
-) extends SampleCombineSignalN[Any, Out](
-  samplingSignal = samplingSignal,
-  sampledSignals = sampledSignal1.toObservable :: sampledSignal2.toObservable :: sampledSignal3.toObservable :: sampledSignal4.toObservable :: sampledSignal5.toObservable :: sampledSignal6.toObservable :: sampledSignal7.toObservable :: sampledSignal8.toObservable :: Nil,
-  combinator = seq => combinator(
-    seq(0).asInstanceOf[T0],
-    seq(1).asInstanceOf[T1],
-    seq(2).asInstanceOf[T2],
-    seq(3).asInstanceOf[T3],
-    seq(4).asInstanceOf[T4],
-    seq(5).asInstanceOf[T5],
-    seq(6).asInstanceOf[T6],
-    seq(7).asInstanceOf[T7],
-    seq(8).asInstanceOf[T8],
-  )
-)
-
-
diff --git a/src/main/scala/com/raquo/airstream/combine/generated/SampleCombineStreams.scala b/src/main/scala/com/raquo/airstream/combine/generated/SampleCombineStreams.scala
deleted file mode 100644
index 8d28239b..00000000
--- a/src/main/scala/com/raquo/airstream/combine/generated/SampleCombineStreams.scala
+++ /dev/null
@@ -1,179 +0,0 @@
-package com.raquo.airstream.combine.generated
-
-import com.raquo.airstream.combine.SampleCombineStreamN
-import com.raquo.airstream.core.EventStream
-import com.raquo.airstream.core.Source.SignalSource
-
-// #Warning do not edit this file directly, it is generated by GenerateSampleCombineStreams.scala
-
-// These are implementations of SampleCombineStreamN used for EventStream's `withCurrentValueOf` and `sample` methods
-
-/** @param combinator Must not throw! */
-class SampleCombineStream2[T0, T1, Out](
-  samplingStream: EventStream[T0],
-  sampledSignal1: SignalSource[T1],
-  combinator: (T0, T1) => Out
-) extends SampleCombineStreamN[Any, Out](
-  samplingStream = samplingStream,
-  sampledSignals = sampledSignal1.toObservable :: Nil,
-  combinator = seq => combinator(
-    seq(0).asInstanceOf[T0],
-    seq(1).asInstanceOf[T1],
-  )
-)
-
-/** @param combinator Must not throw! */
-class SampleCombineStream3[T0, T1, T2, Out](
-  samplingStream: EventStream[T0],
-  sampledSignal1: SignalSource[T1],
-  sampledSignal2: SignalSource[T2],
-  combinator: (T0, T1, T2) => Out
-) extends SampleCombineStreamN[Any, Out](
-  samplingStream = samplingStream,
-  sampledSignals = sampledSignal1.toObservable :: sampledSignal2.toObservable :: Nil,
-  combinator = seq => combinator(
-    seq(0).asInstanceOf[T0],
-    seq(1).asInstanceOf[T1],
-    seq(2).asInstanceOf[T2],
-  )
-)
-
-/** @param combinator Must not throw! */
-class SampleCombineStream4[T0, T1, T2, T3, Out](
-  samplingStream: EventStream[T0],
-  sampledSignal1: SignalSource[T1],
-  sampledSignal2: SignalSource[T2],
-  sampledSignal3: SignalSource[T3],
-  combinator: (T0, T1, T2, T3) => Out
-) extends SampleCombineStreamN[Any, Out](
-  samplingStream = samplingStream,
-  sampledSignals = sampledSignal1.toObservable :: sampledSignal2.toObservable :: sampledSignal3.toObservable :: Nil,
-  combinator = seq => combinator(
-    seq(0).asInstanceOf[T0],
-    seq(1).asInstanceOf[T1],
-    seq(2).asInstanceOf[T2],
-    seq(3).asInstanceOf[T3],
-  )
-)
-
-/** @param combinator Must not throw! */
-class SampleCombineStream5[T0, T1, T2, T3, T4, Out](
-  samplingStream: EventStream[T0],
-  sampledSignal1: SignalSource[T1],
-  sampledSignal2: SignalSource[T2],
-  sampledSignal3: SignalSource[T3],
-  sampledSignal4: SignalSource[T4],
-  combinator: (T0, T1, T2, T3, T4) => Out
-) extends SampleCombineStreamN[Any, Out](
-  samplingStream = samplingStream,
-  sampledSignals = sampledSignal1.toObservable :: sampledSignal2.toObservable :: sampledSignal3.toObservable :: sampledSignal4.toObservable :: Nil,
-  combinator = seq => combinator(
-    seq(0).asInstanceOf[T0],
-    seq(1).asInstanceOf[T1],
-    seq(2).asInstanceOf[T2],
-    seq(3).asInstanceOf[T3],
-    seq(4).asInstanceOf[T4],
-  )
-)
-
-/** @param combinator Must not throw! */
-class SampleCombineStream6[T0, T1, T2, T3, T4, T5, Out](
-  samplingStream: EventStream[T0],
-  sampledSignal1: SignalSource[T1],
-  sampledSignal2: SignalSource[T2],
-  sampledSignal3: SignalSource[T3],
-  sampledSignal4: SignalSource[T4],
-  sampledSignal5: SignalSource[T5],
-  combinator: (T0, T1, T2, T3, T4, T5) => Out
-) extends SampleCombineStreamN[Any, Out](
-  samplingStream = samplingStream,
-  sampledSignals = sampledSignal1.toObservable :: sampledSignal2.toObservable :: sampledSignal3.toObservable :: sampledSignal4.toObservable :: sampledSignal5.toObservable :: Nil,
-  combinator = seq => combinator(
-    seq(0).asInstanceOf[T0],
-    seq(1).asInstanceOf[T1],
-    seq(2).asInstanceOf[T2],
-    seq(3).asInstanceOf[T3],
-    seq(4).asInstanceOf[T4],
-    seq(5).asInstanceOf[T5],
-  )
-)
-
-/** @param combinator Must not throw! */
-class SampleCombineStream7[T0, T1, T2, T3, T4, T5, T6, Out](
-  samplingStream: EventStream[T0],
-  sampledSignal1: SignalSource[T1],
-  sampledSignal2: SignalSource[T2],
-  sampledSignal3: SignalSource[T3],
-  sampledSignal4: SignalSource[T4],
-  sampledSignal5: SignalSource[T5],
-  sampledSignal6: SignalSource[T6],
-  combinator: (T0, T1, T2, T3, T4, T5, T6) => Out
-) extends SampleCombineStreamN[Any, Out](
-  samplingStream = samplingStream,
-  sampledSignals = sampledSignal1.toObservable :: sampledSignal2.toObservable :: sampledSignal3.toObservable :: sampledSignal4.toObservable :: sampledSignal5.toObservable :: sampledSignal6.toObservable :: Nil,
-  combinator = seq => combinator(
-    seq(0).asInstanceOf[T0],
-    seq(1).asInstanceOf[T1],
-    seq(2).asInstanceOf[T2],
-    seq(3).asInstanceOf[T3],
-    seq(4).asInstanceOf[T4],
-    seq(5).asInstanceOf[T5],
-    seq(6).asInstanceOf[T6],
-  )
-)
-
-/** @param combinator Must not throw! */
-class SampleCombineStream8[T0, T1, T2, T3, T4, T5, T6, T7, Out](
-  samplingStream: EventStream[T0],
-  sampledSignal1: SignalSource[T1],
-  sampledSignal2: SignalSource[T2],
-  sampledSignal3: SignalSource[T3],
-  sampledSignal4: SignalSource[T4],
-  sampledSignal5: SignalSource[T5],
-  sampledSignal6: SignalSource[T6],
-  sampledSignal7: SignalSource[T7],
-  combinator: (T0, T1, T2, T3, T4, T5, T6, T7) => Out
-) extends SampleCombineStreamN[Any, Out](
-  samplingStream = samplingStream,
-  sampledSignals = sampledSignal1.toObservable :: sampledSignal2.toObservable :: sampledSignal3.toObservable :: sampledSignal4.toObservable :: sampledSignal5.toObservable :: sampledSignal6.toObservable :: sampledSignal7.toObservable :: Nil,
-  combinator = seq => combinator(
-    seq(0).asInstanceOf[T0],
-    seq(1).asInstanceOf[T1],
-    seq(2).asInstanceOf[T2],
-    seq(3).asInstanceOf[T3],
-    seq(4).asInstanceOf[T4],
-    seq(5).asInstanceOf[T5],
-    seq(6).asInstanceOf[T6],
-    seq(7).asInstanceOf[T7],
-  )
-)
-
-/** @param combinator Must not throw! */
-class SampleCombineStream9[T0, T1, T2, T3, T4, T5, T6, T7, T8, Out](
-  samplingStream: EventStream[T0],
-  sampledSignal1: SignalSource[T1],
-  sampledSignal2: SignalSource[T2],
-  sampledSignal3: SignalSource[T3],
-  sampledSignal4: SignalSource[T4],
-  sampledSignal5: SignalSource[T5],
-  sampledSignal6: SignalSource[T6],
-  sampledSignal7: SignalSource[T7],
-  sampledSignal8: SignalSource[T8],
-  combinator: (T0, T1, T2, T3, T4, T5, T6, T7, T8) => Out
-) extends SampleCombineStreamN[Any, Out](
-  samplingStream = samplingStream,
-  sampledSignals = sampledSignal1.toObservable :: sampledSignal2.toObservable :: sampledSignal3.toObservable :: sampledSignal4.toObservable :: sampledSignal5.toObservable :: sampledSignal6.toObservable :: sampledSignal7.toObservable :: sampledSignal8.toObservable :: Nil,
-  combinator = seq => combinator(
-    seq(0).asInstanceOf[T0],
-    seq(1).asInstanceOf[T1],
-    seq(2).asInstanceOf[T2],
-    seq(3).asInstanceOf[T3],
-    seq(4).asInstanceOf[T4],
-    seq(5).asInstanceOf[T5],
-    seq(6).asInstanceOf[T6],
-    seq(7).asInstanceOf[T7],
-    seq(8).asInstanceOf[T8],
-  )
-)
-
-
diff --git a/src/main/scala/com/raquo/airstream/combine/generated/StaticSignalCombineOps.scala b/src/main/scala/com/raquo/airstream/combine/generated/StaticSignalCombineOps.scala
index 921fff21..ec02347f 100644
--- a/src/main/scala/com/raquo/airstream/combine/generated/StaticSignalCombineOps.scala
+++ b/src/main/scala/com/raquo/airstream/combine/generated/StaticSignalCombineOps.scala
@@ -1,7 +1,9 @@
 package com.raquo.airstream.combine.generated
 
+import com.raquo.airstream.combine.CombineSignalN
 import com.raquo.airstream.core.Signal
 import com.raquo.airstream.core.Source.SignalSource
+import com.raquo.ew.JsArray
 
 // #Warning do not edit this file directly, it is generated by GenerateStaticSignalCombineOps.scala
 
@@ -22,7 +24,13 @@ object StaticSignalCombineOps {
   )(
     combinator: (T1, T2) => Out
   ): Signal[Out] = {
-    new CombineSignal2(s1, s2, combinator)
+    new CombineSignalN[Any, Out](
+      parents = JsArray(s1.toObservable, s2.toObservable),
+      combinator = arr => combinator(
+        arr(0).asInstanceOf[T1],
+        arr(1).asInstanceOf[T2],
+      )
+    )
   }
 
   // --
@@ -39,7 +47,14 @@ object StaticSignalCombineOps {
   )(
     combinator: (T1, T2, T3) => Out
   ): Signal[Out] = {
-    new CombineSignal3(s1, s2, s3, combinator)
+    new CombineSignalN[Any, Out](
+      parents = JsArray(s1.toObservable, s2.toObservable, s3.toObservable),
+      combinator = arr => combinator(
+        arr(0).asInstanceOf[T1],
+        arr(1).asInstanceOf[T2],
+        arr(2).asInstanceOf[T3],
+      )
+    )
   }
 
   // --
@@ -56,7 +71,15 @@ object StaticSignalCombineOps {
   )(
     combinator: (T1, T2, T3, T4) => Out
   ): Signal[Out] = {
-    new CombineSignal4(s1, s2, s3, s4, combinator)
+    new CombineSignalN[Any, Out](
+      parents = JsArray(s1.toObservable, s2.toObservable, s3.toObservable, s4.toObservable),
+      combinator = arr => combinator(
+        arr(0).asInstanceOf[T1],
+        arr(1).asInstanceOf[T2],
+        arr(2).asInstanceOf[T3],
+        arr(3).asInstanceOf[T4],
+      )
+    )
   }
 
   // --
@@ -73,7 +96,16 @@ object StaticSignalCombineOps {
   )(
     combinator: (T1, T2, T3, T4, T5) => Out
   ): Signal[Out] = {
-    new CombineSignal5(s1, s2, s3, s4, s5, combinator)
+    new CombineSignalN[Any, Out](
+      parents = JsArray(s1.toObservable, s2.toObservable, s3.toObservable, s4.toObservable, s5.toObservable),
+      combinator = arr => combinator(
+        arr(0).asInstanceOf[T1],
+        arr(1).asInstanceOf[T2],
+        arr(2).asInstanceOf[T3],
+        arr(3).asInstanceOf[T4],
+        arr(4).asInstanceOf[T5],
+      )
+    )
   }
 
   // --
@@ -90,7 +122,17 @@ object StaticSignalCombineOps {
   )(
     combinator: (T1, T2, T3, T4, T5, T6) => Out
   ): Signal[Out] = {
-    new CombineSignal6(s1, s2, s3, s4, s5, s6, combinator)
+    new CombineSignalN[Any, Out](
+      parents = JsArray(s1.toObservable, s2.toObservable, s3.toObservable, s4.toObservable, s5.toObservable, s6.toObservable),
+      combinator = arr => combinator(
+        arr(0).asInstanceOf[T1],
+        arr(1).asInstanceOf[T2],
+        arr(2).asInstanceOf[T3],
+        arr(3).asInstanceOf[T4],
+        arr(4).asInstanceOf[T5],
+        arr(5).asInstanceOf[T6],
+      )
+    )
   }
 
   // --
@@ -107,7 +149,18 @@ object StaticSignalCombineOps {
   )(
     combinator: (T1, T2, T3, T4, T5, T6, T7) => Out
   ): Signal[Out] = {
-    new CombineSignal7(s1, s2, s3, s4, s5, s6, s7, combinator)
+    new CombineSignalN[Any, Out](
+      parents = JsArray(s1.toObservable, s2.toObservable, s3.toObservable, s4.toObservable, s5.toObservable, s6.toObservable, s7.toObservable),
+      combinator = arr => combinator(
+        arr(0).asInstanceOf[T1],
+        arr(1).asInstanceOf[T2],
+        arr(2).asInstanceOf[T3],
+        arr(3).asInstanceOf[T4],
+        arr(4).asInstanceOf[T5],
+        arr(5).asInstanceOf[T6],
+        arr(6).asInstanceOf[T7],
+      )
+    )
   }
 
   // --
@@ -124,7 +177,19 @@ object StaticSignalCombineOps {
   )(
     combinator: (T1, T2, T3, T4, T5, T6, T7, T8) => Out
   ): Signal[Out] = {
-    new CombineSignal8(s1, s2, s3, s4, s5, s6, s7, s8, combinator)
+    new CombineSignalN[Any, Out](
+      parents = JsArray(s1.toObservable, s2.toObservable, s3.toObservable, s4.toObservable, s5.toObservable, s6.toObservable, s7.toObservable, s8.toObservable),
+      combinator = arr => combinator(
+        arr(0).asInstanceOf[T1],
+        arr(1).asInstanceOf[T2],
+        arr(2).asInstanceOf[T3],
+        arr(3).asInstanceOf[T4],
+        arr(4).asInstanceOf[T5],
+        arr(5).asInstanceOf[T6],
+        arr(6).asInstanceOf[T7],
+        arr(7).asInstanceOf[T8],
+      )
+    )
   }
 
   // --
@@ -141,7 +206,20 @@ object StaticSignalCombineOps {
   )(
     combinator: (T1, T2, T3, T4, T5, T6, T7, T8, T9) => Out
   ): Signal[Out] = {
-    new CombineSignal9(s1, s2, s3, s4, s5, s6, s7, s8, s9, combinator)
+    new CombineSignalN[Any, Out](
+      parents = JsArray(s1.toObservable, s2.toObservable, s3.toObservable, s4.toObservable, s5.toObservable, s6.toObservable, s7.toObservable, s8.toObservable, s9.toObservable),
+      combinator = arr => combinator(
+        arr(0).asInstanceOf[T1],
+        arr(1).asInstanceOf[T2],
+        arr(2).asInstanceOf[T3],
+        arr(3).asInstanceOf[T4],
+        arr(4).asInstanceOf[T5],
+        arr(5).asInstanceOf[T6],
+        arr(6).asInstanceOf[T7],
+        arr(7).asInstanceOf[T8],
+        arr(8).asInstanceOf[T9],
+      )
+    )
   }
 
   // --
diff --git a/src/main/scala/com/raquo/airstream/combine/generated/StaticStreamCombineOps.scala b/src/main/scala/com/raquo/airstream/combine/generated/StaticStreamCombineOps.scala
index 97d19639..3553f67e 100644
--- a/src/main/scala/com/raquo/airstream/combine/generated/StaticStreamCombineOps.scala
+++ b/src/main/scala/com/raquo/airstream/combine/generated/StaticStreamCombineOps.scala
@@ -1,7 +1,9 @@
 package com.raquo.airstream.combine.generated
 
+import com.raquo.airstream.combine.CombineStreamN
 import com.raquo.airstream.core.EventStream
 import com.raquo.airstream.core.Source.EventSource
+import com.raquo.ew.JsArray
 
 // #Warning do not edit this file directly, it is generated by GenerateStaticStreamCombineOps.scala
 
@@ -22,7 +24,13 @@ object StaticStreamCombineOps {
   )(
     combinator: (T1, T2) => Out
   ): EventStream[Out] = {
-    new CombineStream2(s1, s2, combinator)
+    new CombineStreamN[Any, Out](
+      parentStreams = JsArray(s1.toObservable, s2.toObservable),
+      combinator = arr => combinator(
+        arr(0).asInstanceOf[T1],
+        arr(1).asInstanceOf[T2],
+      )
+    )
   }
 
   // --
@@ -39,7 +47,14 @@ object StaticStreamCombineOps {
   )(
     combinator: (T1, T2, T3) => Out
   ): EventStream[Out] = {
-    new CombineStream3(s1, s2, s3, combinator)
+    new CombineStreamN[Any, Out](
+      parentStreams = JsArray(s1.toObservable, s2.toObservable, s3.toObservable),
+      combinator = arr => combinator(
+        arr(0).asInstanceOf[T1],
+        arr(1).asInstanceOf[T2],
+        arr(2).asInstanceOf[T3],
+      )
+    )
   }
 
   // --
@@ -56,7 +71,15 @@ object StaticStreamCombineOps {
   )(
     combinator: (T1, T2, T3, T4) => Out
   ): EventStream[Out] = {
-    new CombineStream4(s1, s2, s3, s4, combinator)
+    new CombineStreamN[Any, Out](
+      parentStreams = JsArray(s1.toObservable, s2.toObservable, s3.toObservable, s4.toObservable),
+      combinator = arr => combinator(
+        arr(0).asInstanceOf[T1],
+        arr(1).asInstanceOf[T2],
+        arr(2).asInstanceOf[T3],
+        arr(3).asInstanceOf[T4],
+      )
+    )
   }
 
   // --
@@ -73,7 +96,16 @@ object StaticStreamCombineOps {
   )(
     combinator: (T1, T2, T3, T4, T5) => Out
   ): EventStream[Out] = {
-    new CombineStream5(s1, s2, s3, s4, s5, combinator)
+    new CombineStreamN[Any, Out](
+      parentStreams = JsArray(s1.toObservable, s2.toObservable, s3.toObservable, s4.toObservable, s5.toObservable),
+      combinator = arr => combinator(
+        arr(0).asInstanceOf[T1],
+        arr(1).asInstanceOf[T2],
+        arr(2).asInstanceOf[T3],
+        arr(3).asInstanceOf[T4],
+        arr(4).asInstanceOf[T5],
+      )
+    )
   }
 
   // --
@@ -90,7 +122,17 @@ object StaticStreamCombineOps {
   )(
     combinator: (T1, T2, T3, T4, T5, T6) => Out
   ): EventStream[Out] = {
-    new CombineStream6(s1, s2, s3, s4, s5, s6, combinator)
+    new CombineStreamN[Any, Out](
+      parentStreams = JsArray(s1.toObservable, s2.toObservable, s3.toObservable, s4.toObservable, s5.toObservable, s6.toObservable),
+      combinator = arr => combinator(
+        arr(0).asInstanceOf[T1],
+        arr(1).asInstanceOf[T2],
+        arr(2).asInstanceOf[T3],
+        arr(3).asInstanceOf[T4],
+        arr(4).asInstanceOf[T5],
+        arr(5).asInstanceOf[T6],
+      )
+    )
   }
 
   // --
@@ -107,7 +149,18 @@ object StaticStreamCombineOps {
   )(
     combinator: (T1, T2, T3, T4, T5, T6, T7) => Out
   ): EventStream[Out] = {
-    new CombineStream7(s1, s2, s3, s4, s5, s6, s7, combinator)
+    new CombineStreamN[Any, Out](
+      parentStreams = JsArray(s1.toObservable, s2.toObservable, s3.toObservable, s4.toObservable, s5.toObservable, s6.toObservable, s7.toObservable),
+      combinator = arr => combinator(
+        arr(0).asInstanceOf[T1],
+        arr(1).asInstanceOf[T2],
+        arr(2).asInstanceOf[T3],
+        arr(3).asInstanceOf[T4],
+        arr(4).asInstanceOf[T5],
+        arr(5).asInstanceOf[T6],
+        arr(6).asInstanceOf[T7],
+      )
+    )
   }
 
   // --
@@ -124,7 +177,19 @@ object StaticStreamCombineOps {
   )(
     combinator: (T1, T2, T3, T4, T5, T6, T7, T8) => Out
   ): EventStream[Out] = {
-    new CombineStream8(s1, s2, s3, s4, s5, s6, s7, s8, combinator)
+    new CombineStreamN[Any, Out](
+      parentStreams = JsArray(s1.toObservable, s2.toObservable, s3.toObservable, s4.toObservable, s5.toObservable, s6.toObservable, s7.toObservable, s8.toObservable),
+      combinator = arr => combinator(
+        arr(0).asInstanceOf[T1],
+        arr(1).asInstanceOf[T2],
+        arr(2).asInstanceOf[T3],
+        arr(3).asInstanceOf[T4],
+        arr(4).asInstanceOf[T5],
+        arr(5).asInstanceOf[T6],
+        arr(6).asInstanceOf[T7],
+        arr(7).asInstanceOf[T8],
+      )
+    )
   }
 
   // --
@@ -141,7 +206,20 @@ object StaticStreamCombineOps {
   )(
     combinator: (T1, T2, T3, T4, T5, T6, T7, T8, T9) => Out
   ): EventStream[Out] = {
-    new CombineStream9(s1, s2, s3, s4, s5, s6, s7, s8, s9, combinator)
+    new CombineStreamN[Any, Out](
+      parentStreams = JsArray(s1.toObservable, s2.toObservable, s3.toObservable, s4.toObservable, s5.toObservable, s6.toObservable, s7.toObservable, s8.toObservable, s9.toObservable),
+      combinator = arr => combinator(
+        arr(0).asInstanceOf[T1],
+        arr(1).asInstanceOf[T2],
+        arr(2).asInstanceOf[T3],
+        arr(3).asInstanceOf[T4],
+        arr(4).asInstanceOf[T5],
+        arr(5).asInstanceOf[T6],
+        arr(6).asInstanceOf[T7],
+        arr(7).asInstanceOf[T8],
+        arr(8).asInstanceOf[T9],
+      )
+    )
   }
 
   // --
diff --git a/src/main/scala/com/raquo/airstream/common/MultiParentSignal.scala b/src/main/scala/com/raquo/airstream/common/MultiParentSignal.scala
index 78589ccd..25e4e1ea 100644
--- a/src/main/scala/com/raquo/airstream/common/MultiParentSignal.scala
+++ b/src/main/scala/com/raquo/airstream/common/MultiParentSignal.scala
@@ -4,35 +4,32 @@ import com.raquo.airstream.core.{Protected, Signal, WritableSignal}
 import com.raquo.ew.JsArray
 
 /** A simple signal that has multiple parents. */
-trait MultiParentSignal[+I, O] extends WritableSignal[O] {
+trait MultiParentSignal[I, O] extends WritableSignal[O] {
 
-  // #nc[perf] should this maybe be js.Array?
-  protected[this] val parents: Seq[Signal[I]]
+  /** This array is read-only, never update it. */
+  protected[this] val parents: JsArray[Signal[I]]
 
-  protected[this] lazy val _parentLastUpdateIds: JsArray[Int] = JsArray(parents.map(Protected.lastUpdateId): _*) // #nc inefficient
+  protected[this] lazy val _parentLastUpdateIds: JsArray[Int] = parents.map(Protected.lastUpdateId(_))
 
   override protected def onWillStart(): Unit = {
-    // #nc redundant loop eh? ugly af
-    parents.foreach(Protected.maybeWillStart)
-    val shouldPullFromParent = updateParentLastTrxIds()
+    parents.forEach(Protected.maybeWillStart(_))
+    val shouldPullFromParent = updateParentLastUpdateIds()
     if (shouldPullFromParent) {
       updateCurrentValueFromParent()
     }
   }
 
   /** @return Whether parent has emitted since last time we checked */
-  protected[this] def updateParentLastTrxIds(): Boolean = {
-    var ix = 0
+  protected[this] def updateParentLastUpdateIds(): Boolean = {
     var parentHasUpdated = false
-    while (ix < parents.size) {
-      val newLastTrxId = Protected.lastUpdateId(parents(ix))
-      val lastSeenParentTrxId = _parentLastUpdateIds(ix)
-      if (newLastTrxId != lastSeenParentTrxId) {
-        _parentLastUpdateIds.update(ix, newLastTrxId)
+    parents.forEachWithIndex { (parent, ix) => {
+      val newLastUpdateId = Protected.lastUpdateId(parent)
+      val lastSeenParentUpdateId = _parentLastUpdateIds(ix)
+      if (newLastUpdateId != lastSeenParentUpdateId) {
+        _parentLastUpdateIds.update(ix, newLastUpdateId)
         parentHasUpdated = true
       }
-      ix += 1
-    }
+    }}
     parentHasUpdated
   }
 
diff --git a/src/main/scala/com/raquo/airstream/common/MultiParentStream.scala b/src/main/scala/com/raquo/airstream/common/MultiParentStream.scala
index 94a1c289..c98b005c 100644
--- a/src/main/scala/com/raquo/airstream/common/MultiParentStream.scala
+++ b/src/main/scala/com/raquo/airstream/common/MultiParentStream.scala
@@ -1,14 +1,16 @@
 package com.raquo.airstream.common
 
 import com.raquo.airstream.core.{Observable, Protected, WritableStream}
+import com.raquo.ew.JsArray
 
 /** A simple stream that has multiple parents. */
-trait MultiParentStream[+I, O] extends WritableStream[O] {
+trait MultiParentStream[I, O] extends WritableStream[O] {
 
-  protected[this] val parents: Seq[Observable[I]]
+  /** This array is read-only, never update it. */
+  protected[this] val parents: JsArray[Observable[I]]
 
   override protected def onWillStart(): Unit = {
-    parents.foreach(Protected.maybeWillStart)
+    parents.forEach(Protected.maybeWillStart(_))
   }
 
 }
diff --git a/src/main/scala/com/raquo/airstream/core/BaseObservable.scala b/src/main/scala/com/raquo/airstream/core/BaseObservable.scala
index e92e9096..6a421498 100644
--- a/src/main/scala/com/raquo/airstream/core/BaseObservable.scala
+++ b/src/main/scala/com/raquo/airstream/core/BaseObservable.scala
@@ -265,8 +265,6 @@ trait BaseObservable[+Self[+_] <: Observable[_], +A] extends Source[A] with Name
     }
   }
 
-  // #nc make onStart / onStop non-abstract
-
   /** This method is fired when this observable starts working (listening for parent events and/or firing its own events),
     * that is, when it gets its first Observer (internal or external).
     *
diff --git a/src/main/scala/com/raquo/airstream/core/EventStream.scala b/src/main/scala/com/raquo/airstream/core/EventStream.scala
index 8b042922..93e1cf54 100644
--- a/src/main/scala/com/raquo/airstream/core/EventStream.scala
+++ b/src/main/scala/com/raquo/airstream/core/EventStream.scala
@@ -12,6 +12,7 @@ import com.raquo.airstream.misc._
 import com.raquo.airstream.misc.generated._
 import com.raquo.airstream.split.{SplittableOneStream, SplittableOptionStream, SplittableStream}
 import com.raquo.airstream.timing._
+import com.raquo.ew.JsArray
 
 import scala.annotation.unused
 import scala.concurrent.{ExecutionContext, Future}
@@ -400,18 +401,18 @@ object EventStream {
   }
 
   def sequence[A](streams: Seq[EventStream[A]]): EventStream[Seq[A]] = {
-    new CombineStreamN[A, Seq[A]](streams, identity)
+    new CombineStreamN[A, Seq[A]](JsArray(streams: _*), _.asScalaJs.toSeq)
   }
 
   @inline def combineSeq[A](streams: Seq[EventStream[A]]): EventStream[Seq[A]] = sequence(streams)
 
   /** Returns a stream that emits events from all off the `streams`, interleaved. */
   def merge[A](streams: EventStream[A]*): EventStream[A] = {
-    new MergeStream[A](streams)
+    new MergeStream[A](JsArray(streams: _*))
   }
 
-  @inline def mergeSeq[A](streams: Seq[EventStream[A]]): EventStream[A] = {
-    merge(streams: _*) // @TODO[Performance] Does _* introduce any overhead in Scala.js?
+  def mergeSeq[A](streams: Seq[EventStream[A]]): EventStream[A] = {
+    new MergeStream[A](JsArray(streams: _*))
   }
 
   /** Provides methods on EventStream companion object: combine, combineWith */
diff --git a/src/main/scala/com/raquo/airstream/core/Protected.scala b/src/main/scala/com/raquo/airstream/core/Protected.scala
index 9b0f07da..0a3450a8 100644
--- a/src/main/scala/com/raquo/airstream/core/Protected.scala
+++ b/src/main/scala/com/raquo/airstream/core/Protected.scala
@@ -1,5 +1,7 @@
 package com.raquo.airstream.core
 
+import com.raquo.ew.JsArray
+
 import scala.annotation.{implicitNotFound, unused}
 import scala.util.Try
 
@@ -26,10 +28,39 @@ object Protected {
     BaseObservable.topoRank(observable)
   }
 
+  // Note: this implementation is not used in Airstream, and is provided
+  // only for third party developers who don't want to use JsArray.
   def maxTopoRank[O[+_] <: Observable[_]](observables: Iterable[BaseObservable[O, _]]): Int = {
     observables.foldLeft(0)((maxRank, parent) => Protected.topoRank(parent) max maxRank)
   }
 
+  @inline def maxTopoRank[O <: Observable[_]](
+    observables: JsArray[O]
+  ): Int = {
+    maxTopoRank(minRank = 0, observables)
+  }
+
+  def maxTopoRank[O <: Observable[_]](
+    observable: Observable[_],
+    observables: JsArray[O]
+  ): Int = {
+    maxTopoRank(minRank = Protected.topoRank(observable), observables)
+  }
+
+  def maxTopoRank[O <: Observable[_]](
+    minRank: Int,
+    observables: JsArray[O]
+  ): Int = {
+    var maxRank = minRank
+    observables.forEach { observable =>
+      val rank = Protected.topoRank(observable)
+      if (rank > maxRank) {
+        maxRank = rank
+      }
+    }
+    maxRank
+  }
+
   def lastUpdateId(signal: Signal[_])(implicit @unused ev: Protected): Int = signal.lastUpdateId
 
   @inline def tryNow[A](signal: Signal[A])(implicit @unused ev: Protected): Try[A] = signal.tryNow()
diff --git a/src/main/scala/com/raquo/airstream/core/Signal.scala b/src/main/scala/com/raquo/airstream/core/Signal.scala
index 2e669b72..8a7c7f35 100644
--- a/src/main/scala/com/raquo/airstream/core/Signal.scala
+++ b/src/main/scala/com/raquo/airstream/core/Signal.scala
@@ -8,11 +8,12 @@ import com.raquo.airstream.custom.{CustomSignalSource, CustomSource}
 import com.raquo.airstream.debug.{DebuggableSignal, Debugger, DebuggerSignal}
 import com.raquo.airstream.distinct.DistinctSignal
 import com.raquo.airstream.misc.generated._
-import com.raquo.airstream.misc.{StreamFromSignal, MapSignal, ScanLeftSignal}
+import com.raquo.airstream.misc.{MapSignal, ScanLeftSignal, StreamFromSignal}
 import com.raquo.airstream.ownership.Owner
 import com.raquo.airstream.split.{SplittableOneSignal, SplittableOptionSignal, SplittableSignal}
 import com.raquo.airstream.state.{ObservedSignal, OwnedSignal, Val}
 import com.raquo.airstream.timing.JsPromiseSignal
+import com.raquo.ew.JsArray
 
 import scala.annotation.unused
 import scala.concurrent.{ExecutionContext, Future}
@@ -214,7 +215,7 @@ object Signal {
   def sequence[A](
     signals: Seq[Signal[A]]
   ): Signal[Seq[A]] = {
-    new CombineSignalN[A, Seq[A]](signals, identity)
+    new CombineSignalN[A, Seq[A]](JsArray(signals: _*), _.asScalaJs.toSeq)
   }
 
   @inline def combineSeq[A](signals: Seq[Signal[A]]): Signal[Seq[A]] = sequence(signals)
diff --git a/src/main/scala/com/raquo/airstream/core/Source.scala b/src/main/scala/com/raquo/airstream/core/Source.scala
index d4420d7b..3a5faabf 100644
--- a/src/main/scala/com/raquo/airstream/core/Source.scala
+++ b/src/main/scala/com/raquo/airstream/core/Source.scala
@@ -27,7 +27,7 @@ object Source {
     override def toObservable: Signal[A]
   }
 
-  // #TODO[API] Disable integrations, see if anyone complains. These conversions are unfortunately not smooth enough to be implicit.
+  // #TODO[API] Disabled integrations, let's see if anyone complains. These conversions are unfortunately not smooth enough to be implicit.
 
   //implicit def futureToEventSource[A](future: Future[A]): EventSource[A] = EventStream.fromFuture(future)
   //
diff --git a/src/test/scala/com/raquo/airstream/flatten/SwitchSignalSpec.scala b/src/test/scala/com/raquo/airstream/flatten/SwitchSignalSpec.scala
index 1c5af21d..8a51e775 100644
--- a/src/test/scala/com/raquo/airstream/flatten/SwitchSignalSpec.scala
+++ b/src/test/scala/com/raquo/airstream/flatten/SwitchSignalSpec.scala
@@ -375,11 +375,6 @@ class SwitchSignalSpec extends UnitSpec {
         .flatMap { num =>
           if (num < 1000) {
             smallI += 1
-            // #TODO[API]: if this `intSignal.map("small: " + _)` signal was cached / reused instead, it would
-            //  result in duplicate events, which is not great, but kind of expected, because SwitchSignal
-            //  ensures that it emits an event every time that the parent emits, for consistency. But since
-            //  the inner signal is also the parent signal, this results in event duplication.
-            //  - See the isSameSignal logic in SwitchSignal
             intSignal.map("small: " + _).setDisplayName(s"small-$smallI") //.debugLogLifecycle()
           } else {
             bigI += 1