diff --git a/tracker/derived.go b/tracker/derived.go
index 9884347..457ce0e 100644
--- a/tracker/derived.go
+++ b/tracker/derived.go
@@ -14,11 +14,12 @@ type (
 	}
 
 	Wire struct {
-		From    int
-		FromSet bool
-		To      Point
-		ToSet   bool
-		Hint    string
+		From      int
+		FromSet   bool
+		To        Point
+		ToSet     bool
+		Hint      string
+		Highlight bool
 	}
 
 	RailError struct {
@@ -68,6 +69,7 @@ func (m *Model) Wires(yield func(wire Wire) bool) {
 		return
 	}
 	for _, wire := range m.derived.patch[i].wires {
+		wire.Highlight = (wire.FromSet && m.d.UnitIndex == wire.From) || (wire.ToSet && m.d.UnitIndex == wire.To.Y && m.d.ParamIndex == wire.To.X)
 		if !yield(wire) {
 			return
 		}
@@ -258,7 +260,7 @@ func (m *Model) updateRails() {
 			m.derived.patch[i].rails[u] = Rail{
 				PassThrough: len(scratch),
 				StackUse:    stackUse,
-				Send:        unit.Type == "send",
+				Send:        !unit.Disabled && unit.Type == "send",
 			}
 			maxWidth = max(maxWidth, len(scratch)+max(len(stackUse.Inputs), stackUse.NumOutputs))
 			for range stackUse.NumOutputs {
@@ -308,7 +310,7 @@ func (m *Model) updateWires() {
 	}
 	for i, instr := range m.d.Song.Patch {
 		for u, unit := range instr.Units {
-			if unit.Type != "send" {
+			if unit.Disabled || unit.Type != "send" {
 				continue
 			}
 			tI, tU, err := m.d.Song.Patch.FindUnit(unit.Parameters["target"])
diff --git a/tracker/gioui/knob.go b/tracker/gioui/knob.go
index 9014d0b..c847268 100644
--- a/tracker/gioui/knob.go
+++ b/tracker/gioui/knob.go
@@ -82,12 +82,13 @@ type (
 	}
 
 	SwitchWidget struct {
-		Theme  *Theme
-		Value  tracker.Parameter
-		State  *KnobState
-		Style  *SwitchStyle
-		Hint   string
-		Scroll bool
+		Theme    *Theme
+		Value    tracker.Parameter
+		State    *KnobState
+		Style    *SwitchStyle
+		Hint     string
+		Scroll   bool
+		Disabled bool
 	}
 )
 
@@ -141,8 +142,8 @@ func (s *KnobState) update(gtx C, param tracker.Parameter, scroll bool) {
 
 // Knob
 
-func Knob(v tracker.Parameter, th *Theme, state *KnobState, hint string, scroll bool) KnobWidget {
-	return KnobWidget{
+func Knob(v tracker.Parameter, th *Theme, state *KnobState, hint string, scroll, disabled bool) KnobWidget {
+	ret := KnobWidget{
 		Theme:  th,
 		Value:  v,
 		State:  state,
@@ -150,6 +151,10 @@ func Knob(v tracker.Parameter, th *Theme, state *KnobState, hint string, scroll
 		Hint:   hint,
 		Scroll: scroll,
 	}
+	if disabled {
+		ret.Style = &th.DisabledKnob
+	}
+	return ret
 }
 
 func (k *KnobWidget) Layout(gtx C) D {
@@ -248,14 +253,15 @@ func (k *KnobWidget) strokeIndicator(gtx C, amount float32) {
 
 // Switch
 
-func Switch(v tracker.Parameter, th *Theme, state *KnobState, hint string, scroll bool) SwitchWidget {
+func Switch(v tracker.Parameter, th *Theme, state *KnobState, hint string, scroll, disabled bool) SwitchWidget {
 	return SwitchWidget{
-		Theme:  th,
-		Value:  v,
-		State:  state,
-		Style:  &th.Switch,
-		Hint:   hint,
-		Scroll: scroll,
+		Theme:    th,
+		Value:    v,
+		State:    state,
+		Style:    &th.Switch,
+		Hint:     hint,
+		Scroll:   scroll,
+		Disabled: disabled,
 	}
 }
 
@@ -266,13 +272,13 @@ func (s *SwitchWidget) Layout(gtx C) D {
 	var fg, bg color.NRGBA
 	o := 0
 	switch {
-	case s.Value.Value() < 0:
-		fg = s.Style.Neg.Fg
-		bg = s.Style.Neg.Bg
-	case s.Value.Value() == 0:
+	case s.Disabled || s.Value.Value() == 0:
 		fg = s.Style.Neutral.Fg
 		bg = s.Style.Neutral.Bg
 		o = gtx.Dp(s.Style.Outline)
+	case s.Value.Value() < 0:
+		fg = s.Style.Neg.Fg
+		bg = s.Style.Neg.Bg
 	case s.Value.Value() > 0:
 		fg = s.Style.Pos.Fg
 		bg = s.Style.Pos.Bg
diff --git a/tracker/gioui/theme.go b/tracker/gioui/theme.go
index cdaabda..9f8a21e 100644
--- a/tracker/gioui/theme.go
+++ b/tracker/gioui/theme.go
@@ -85,15 +85,16 @@ type Theme struct {
 		}
 	}
 	UnitEditor struct {
-		Name        LabelStyle
-		Chooser     LabelStyle
-		Hint        LabelStyle
-		WireColor   color.NRGBA
-		WireHint    LabelStyle
-		Width       unit.Dp
-		Height      unit.Dp
-		RackComment LabelStyle
-		UnitList    struct {
+		Name          LabelStyle
+		Chooser       LabelStyle
+		Hint          LabelStyle
+		WireColor     color.NRGBA
+		WireHint      LabelStyle
+		WireHighlight color.NRGBA
+		Width         unit.Dp
+		Height        unit.Dp
+		RackComment   LabelStyle
+		UnitList      struct {
 			LabelWidth unit.Dp
 			Name       LabelStyle
 			Disabled   LabelStyle
@@ -112,12 +113,13 @@ type Theme struct {
 		Menu   PopupStyle
 		Dialog PopupStyle
 	}
-	Split      SplitStyle
-	ScrollBar  ScrollBarStyle
-	Knob       KnobStyle
-	Switch     SwitchStyle
-	SignalRail SignalRailStyle
-	Port       PortStyle
+	Split        SplitStyle
+	ScrollBar    ScrollBarStyle
+	Knob         KnobStyle
+	DisabledKnob KnobStyle
+	Switch       SwitchStyle
+	SignalRail   SignalRailStyle
+	Port         PortStyle
 
 	// iconCache is used to cache the icons created from iconvg data
 	iconCache map[*byte]*widget.Icon
diff --git a/tracker/gioui/theme.yml b/tracker/gioui/theme.yml
index f9c4bf3..4c89fdc 100644
--- a/tracker/gioui/theme.yml
+++ b/tracker/gioui/theme.yml
@@ -211,6 +211,7 @@ uniteditor:
   name:
     { textsize: 12, alignment: 2, color: *highemphasis, shadowcolor: *black }
   wirecolor: *secondarycolor
+  wirehighlight: *white
   wirehint: { textsize: 12, color: *disabled, shadowcolor: *black }
   width: 60
   height: 70
@@ -230,6 +231,14 @@ knob:
   pos: { color: *primarycolor, bg: { r: 51, g: 36, b: 54, a: 255 } }
   neg: { color: *secondarycolor, bg: { r: 32, g: 55, b: 58, a: 255 } }
   indicator: { color: *white, width: 2, innerdiam: 24, outerdiam: 36 }
+disabledknob:
+  diameter: 36
+  value: { textsize: 12, color: { r: 147, g: 143, b: 153, a: 255 }}
+  strokewidth: 4
+  bg: { r: 40, g: 40, b: 40, a: 255 }
+  pos: { color: { r: 147, g: 143, b: 153, a: 255 }, bg: { r: 54, g: 52, b: 59, a: 255 } }
+  neg: { color: { r: 147, g: 143, b: 153, a: 255 }, bg: { r: 54, g: 52, b: 59, a: 255 } }
+  indicator: { color: { r: 147, g: 143, b: 153, a: 255 }, width: 2, innerdiam: 24, outerdiam: 36 }
 signalrail:
   color: *secondarycolor
   signalwidth: 10
diff --git a/tracker/gioui/unit_editor.go b/tracker/gioui/unit_editor.go
index 276e4e9..7e3f73f 100644
--- a/tracker/gioui/unit_editor.go
+++ b/tracker/gioui/unit_editor.go
@@ -3,6 +3,7 @@ package gioui
 import (
 	"bytes"
 	"image"
+	"image/color"
 	"io"
 	"math"
 	"time"
@@ -247,7 +248,7 @@ func (pe *UnitEditor) layoutRack(gtx C) D {
 		}
 
 		param := t.Model.Params().Item(point)
-		paramStyle := t.ParamStyle(param, t.Theme, pe.Parameters[y][x], pe.paramTable.Table.Cursor() == point)
+		paramStyle := t.ParamStyle(param, t.Theme, pe.Parameters[y][x], pe.paramTable.Table.Cursor() == point, t.Units().Item(y).Disabled)
 		paramStyle.Layout(gtx)
 		comment := t.Units().Item(y).Comment
 		if comment != "" && x == t.Model.Params().RowWidth(y) {
@@ -281,13 +282,17 @@ func (pe *UnitEditor) drawSignals(gtx C, rowTitleWidth int) {
 	defer clip.Rect(image.Rectangle{Max: gtx.Constraints.Max}).Push(gtx.Ops).Pop()
 	defer op.Offset(image.Pt(-colP.Offset, -rowP.Offset)).Push(gtx.Ops).Pop()
 	for wire := range t.Wires {
+		clr := t.Theme.UnitEditor.WireColor
+		if wire.Highlight {
+			clr = t.Theme.UnitEditor.WireHighlight
+		}
 		switch {
 		case wire.FromSet && !wire.ToSet:
 			pe.drawRemoteSendSignal(gtx, wire, colP.First, rowP.First)
 		case !wire.FromSet && wire.ToSet:
-			pe.drawRemoteReceiveSignal(gtx, wire, colP.First, rowP.First)
+			pe.drawRemoteReceiveSignal(gtx, wire, colP.First, rowP.First, clr)
 		case wire.FromSet && wire.ToSet:
-			pe.drawSignal(gtx, wire, colP.First, rowP.First)
+			pe.drawSignal(gtx, wire, colP.First, rowP.First, clr)
 		}
 	}
 }
@@ -309,7 +314,7 @@ func (pe *UnitEditor) drawRemoteSendSignal(gtx C, wire tracker.Wire, col, row in
 	Label(t.Theme, &t.Theme.UnitEditor.WireHint, wire.Hint).Layout(gtx)
 }
 
-func (pe *UnitEditor) drawRemoteReceiveSignal(gtx C, wire tracker.Wire, col, row int) {
+func (pe *UnitEditor) drawRemoteReceiveSignal(gtx C, wire tracker.Wire, col, row int, clr color.NRGBA) {
 	ex := wire.To.X - col
 	ey := wire.To.Y - row
 	t := TrackerFromContext(gtx)
@@ -328,7 +333,7 @@ func (pe *UnitEditor) drawRemoteReceiveSignal(gtx C, wire tracker.Wire, col, row
 	path.Begin(gtx.Ops)
 	path.MoveTo(from)
 	path.CubeTo(c1, c2, to)
-	paint.FillShape(gtx.Ops, t.Theme.UnitEditor.WireColor,
+	paint.FillShape(gtx.Ops, clr,
 		clip.Stroke{
 			Path:  path.End(),
 			Width: float32(gtx.Dp(t.Theme.SignalRail.LineWidth)),
@@ -337,7 +342,7 @@ func (pe *UnitEditor) drawRemoteReceiveSignal(gtx C, wire tracker.Wire, col, row
 	Label(t.Theme, &t.Theme.UnitEditor.WireHint, wire.Hint).Layout(gtx)
 }
 
-func (pe *UnitEditor) drawSignal(gtx C, wire tracker.Wire, col, row int) {
+func (pe *UnitEditor) drawSignal(gtx C, wire tracker.Wire, col, row int, clr color.NRGBA) {
 	sy := wire.From - row
 	ex := wire.To.X - col
 	ey := wire.To.Y - row
@@ -371,7 +376,7 @@ func (pe *UnitEditor) drawSignal(gtx C, wire tracker.Wire, col, row int) {
 	path.MoveTo(from)
 	path.CubeTo(from.Add(fromTan), p1.Sub(p1Tan), p1)
 	path.CubeTo(p1.Add(p1Tan), p2, to)
-	paint.FillShape(gtx.Ops, t.Theme.UnitEditor.WireColor,
+	paint.FillShape(gtx.Ops, clr,
 		clip.Stroke{
 			Path:  path.End(),
 			Width: float32(gtx.Dp(t.Theme.SignalRail.LineWidth)),
@@ -450,14 +455,16 @@ type ParameterStyle struct {
 	State     *ParameterState
 	Theme     *Theme
 	Focus     bool
+	Disabled  bool
 }
 
-func (t *Tracker) ParamStyle(Parameter tracker.Parameter, th *Theme, paramWidget *ParameterState, focus bool) ParameterStyle {
+func (t *Tracker) ParamStyle(Parameter tracker.Parameter, th *Theme, paramWidget *ParameterState, focus, disabled bool) ParameterStyle {
 	return ParameterStyle{
 		Theme:     th,
 		State:     paramWidget,
 		Parameter: Parameter,
 		Focus:     focus,
+		Disabled:  disabled,
 	}
 }
 
@@ -474,13 +481,19 @@ func (p ParameterStyle) Layout(gtx C) D {
 		}
 		switch p.Parameter.Type() {
 		case tracker.IntegerParameter:
-			k := Knob(p.Parameter, p.Theme, &p.State.knobState, p.Parameter.Hint().Label, p.Focus)
+			k := Knob(p.Parameter, p.Theme, &p.State.knobState, p.Parameter.Hint().Label, p.Focus, p.Disabled)
 			return k.Layout(gtx)
 		case tracker.BoolParameter:
-			s := Switch(p.Parameter, p.Theme, &p.State.knobState, p.Parameter.Hint().Label, p.Focus)
+			s := Switch(p.Parameter, p.Theme, &p.State.knobState, p.Parameter.Hint().Label, p.Focus, p.Disabled)
 			return s.Layout(gtx)
 		case tracker.IDParameter:
-			btn := ActionBtn(t.ChooseSendSource(p.Parameter.UnitID()), t.Theme, &p.State.clickable, "Set", p.Parameter.Hint().Label)
+			for p.State.clickable.Clicked(gtx) {
+				t.ChooseSendSource(p.Parameter.UnitID()).Do()
+			}
+			btn := Btn(t.Theme, &t.Theme.Button.Text, &p.State.clickable, "Set", p.Parameter.Hint().Label)
+			if p.Disabled {
+				btn.Style = &t.Theme.Button.Disabled
+			}
 			return btn.Layout(gtx)
 		}
 		if _, ok := p.Parameter.Port(); ok {
diff --git a/tracker/presets.go b/tracker/presets.go
index d3674a3..94e0be6 100644
--- a/tracker/presets.go
+++ b/tracker/presets.go
@@ -76,7 +76,7 @@ var defaultUnits = map[string]sointu.Unit{
 	"in":         {Type: "in", Parameters: map[string]int{"stereo": 1, "channel": 2}},
 	"speed":      {Type: "speed", Parameters: map[string]int{}},
 	"compressor": {Type: "compressor", Parameters: map[string]int{"stereo": 0, "attack": 64, "release": 64, "invgain": 64, "threshold": 64, "ratio": 64}},
-	"send":       {Type: "send", Parameters: map[string]int{"stereo": 0, "amount": 128, "voice": 0, "unit": 0, "port": 0, "sendpop": 1}},
+	"send":       {Type: "send", Parameters: map[string]int{"stereo": 0, "amount": 64, "voice": 0, "unit": 0, "port": 0, "sendpop": 1}},
 	"sync":       {Type: "sync", Parameters: map[string]int{}},
 }