diff --git a/include/app/Knob.hpp b/include/app/Knob.hpp
index a56e4122..5e2f3746 100644
--- a/include/app/Knob.hpp
+++ b/include/app/Knob.hpp
@@ -15,6 +15,7 @@ struct Knob : ParamWidget {
 	/** Multiplier for mouse movement to adjust knob value */
 	float speed = 1.0;
 
+	void onButton(event::Button &e) override;
 	void onDragStart(event::DragStart &e) override;
 	void onDragEnd(event::DragEnd &e) override;
 	void onDragMove(event::DragMove &e) override;
diff --git a/include/app/ParamWidget.hpp b/include/app/ParamWidget.hpp
index b9a6138f..382c6d04 100644
--- a/include/app/ParamWidget.hpp
+++ b/include/app/ParamWidget.hpp
@@ -9,12 +9,14 @@ namespace rack {
 
 struct ParamWidget : OpaqueWidget {
 	Quantity *quantity = NULL;
+	float dirtyValue = NAN;
 
 	~ParamWidget() {
 		if (quantity)
 			delete quantity;
 	}
 
+	void step() override;
 	/** For legacy patch loading */
 	void fromJson(json_t *rootJ);
 	void onButton(event::Button &e) override;
diff --git a/include/app/SVGSwitch.hpp b/include/app/SVGSwitch.hpp
index d87fdd10..8252b14f 100644
--- a/include/app/SVGSwitch.hpp
+++ b/include/app/SVGSwitch.hpp
@@ -15,6 +15,7 @@ struct SVGSwitch : virtual ParamWidget, FramebufferWidget {
 	SVGWidget *sw;
 
 	SVGSwitch();
+	void step() override;
 	/** Adds an SVG file to represent the next switch position */
 	void addFrame(std::shared_ptr<SVG> svg);
 	void onChange(event::Change &e) override;
diff --git a/src/app/Knob.cpp b/src/app/Knob.cpp
index 030c772a..7f9fcff3 100644
--- a/src/app/Knob.cpp
+++ b/src/app/Knob.cpp
@@ -4,6 +4,15 @@
 namespace rack {
 
 
+void Knob::onButton(event::Button &e) {
+	float r = box.size.x / 2;
+	math::Vec c = box.size.div(2);
+	float dist = e.pos.minus(c).norm();
+	if (dist <= r) {
+		ParamWidget::onButton(e);
+	}
+}
+
 void Knob::onDragStart(event::DragStart &e) {
 	context()->window->cursorLock();
 }
@@ -28,9 +37,6 @@ void Knob::onDragMove(event::DragMove &e) {
 		if (context()->window->isModPressed())
 			delta /= 16.f;
 		quantity->moveValue(delta);
-
-		event::Change eChange;
-		onChange(eChange);
 	}
 }
 
diff --git a/src/app/ParamWidget.cpp b/src/app/ParamWidget.cpp
index 2b59175f..cf1dbb04 100644
--- a/src/app/ParamWidget.cpp
+++ b/src/app/ParamWidget.cpp
@@ -5,6 +5,20 @@
 namespace rack {
 
 
+void ParamWidget::step() {
+	if (quantity) {
+		float value = quantity->getValue();
+		// Trigger change event when quantity value changes
+		if (value != dirtyValue) {
+			dirtyValue = value;
+			event::Change eChange;
+			onChange(eChange);
+		}
+	}
+
+	OpaqueWidget::step();
+}
+
 void ParamWidget::fromJson(json_t *rootJ) {
 	json_t *valueJ = json_object_get(rootJ, "value");
 	if (valueJ) {
@@ -20,7 +34,6 @@ void ParamWidget::onButton(event::Button &e) {
 			quantity->reset();
 		// Here's another way of doing it, but either works.
 		// dynamic_cast<ParamQuantity*>(quantity)->getParam()->reset();
-		return;
 	}
 
 	OpaqueWidget::onButton(e);
diff --git a/src/app/SVGKnob.cpp b/src/app/SVGKnob.cpp
index 04655a41..cd63f951 100644
--- a/src/app/SVGKnob.cpp
+++ b/src/app/SVGKnob.cpp
@@ -26,8 +26,13 @@ void SVGKnob::setSVG(std::shared_ptr<SVG> svg) {
 }
 
 void SVGKnob::step() {
-	// Re-transform TransformWidget if dirty
-	if (dirty && quantity) {
+	Knob::step();
+	FramebufferWidget::step();
+}
+
+void SVGKnob::onChange(event::Change &e) {
+	// Re-transform the TransformWidget
+	if (quantity) {
 		float angle;
 		if (quantity->isBounded()) {
 			angle = math::rescale(quantity->getScaledValue(), 0.f, 1.f, minAngle, maxAngle);
@@ -42,12 +47,8 @@ void SVGKnob::step() {
 		tw->translate(center);
 		tw->rotate(angle);
 		tw->translate(center.neg());
+		dirty = true;
 	}
-	FramebufferWidget::step();
-}
-
-void SVGKnob::onChange(event::Change &e) {
-	dirty = true;
 	Knob::onChange(e);
 }
 
diff --git a/src/app/SVGSlider.cpp b/src/app/SVGSlider.cpp
index c5210aa7..e135b319 100644
--- a/src/app/SVGSlider.cpp
+++ b/src/app/SVGSlider.cpp
@@ -23,18 +23,19 @@ void SVGSlider::setSVGs(std::shared_ptr<SVG> backgroundSVG, std::shared_ptr<SVG>
 }
 
 void SVGSlider::step() {
-	if (dirty && quantity) {
+	Knob::step();
+	FramebufferWidget::step();
+}
+
+void SVGSlider::onChange(event::Change &e) {
+	if (quantity) {
 		// Interpolate handle position
 		float v = quantity->getScaledValue();
 		handle->box.pos = math::Vec(
 			math::rescale(v, 0.f, 1.f, minHandlePos.x, maxHandlePos.x),
 			math::rescale(v, 0.f, 1.f, minHandlePos.y, maxHandlePos.y));
+		dirty = true;
 	}
-	FramebufferWidget::step();
-}
-
-void SVGSlider::onChange(event::Change &e) {
-	dirty = true;
 	ParamWidget::onChange(e);
 }
 
diff --git a/src/app/SVGSwitch.cpp b/src/app/SVGSwitch.cpp
index e682dfd5..549bca95 100644
--- a/src/app/SVGSwitch.cpp
+++ b/src/app/SVGSwitch.cpp
@@ -9,6 +9,11 @@ SVGSwitch::SVGSwitch() {
 	addChild(sw);
 }
 
+void SVGSwitch::step() {
+	ParamWidget::step();
+	FramebufferWidget::step();
+}
+
 void SVGSwitch::addFrame(std::shared_ptr<SVG> svg) {
 	frames.push_back(svg);
 	// If this is our first frame, automatically set SVG and size
diff --git a/src/app/WireWidget.cpp b/src/app/WireWidget.cpp
index d04cd560..c279a87a 100644
--- a/src/app/WireWidget.cpp
+++ b/src/app/WireWidget.cpp
@@ -31,7 +31,7 @@ static void drawPlug(NVGcontext *vg, math::Vec pos, NVGcolor color) {
 	nvgFill(vg);
 }
 
-static void drawWire(NVGcontext *vg, math::Vec pos1, math::Vec pos2, NVGcolor color, float width, float tension, float opacity) {
+static void drawWire(NVGcontext *vg, math::Vec pos1, math::Vec pos2, NVGcolor color, float thickness, float tension, float opacity) {
 	NVGcolor colorShadow = nvgRGBAf(0, 0, 0, 0.10);
 	NVGcolor colorOutline = nvgLerpRGBA(color, nvgRGBf(0.0, 0.0, 0.0), 0.5);
 
@@ -54,7 +54,7 @@ static void drawWire(NVGcontext *vg, math::Vec pos1, math::Vec pos2, NVGcolor co
 		nvgMoveTo(vg, pos1.x, pos1.y);
 		nvgQuadTo(vg, pos4.x, pos4.y, pos2.x, pos2.y);
 		nvgStrokeColor(vg, colorShadow);
-		nvgStrokeWidth(vg, width);
+		nvgStrokeWidth(vg, thickness);
 		nvgStroke(vg);
 
 		// Wire outline
@@ -62,12 +62,12 @@ static void drawWire(NVGcontext *vg, math::Vec pos1, math::Vec pos2, NVGcolor co
 		nvgMoveTo(vg, pos1.x, pos1.y);
 		nvgQuadTo(vg, pos3.x, pos3.y, pos2.x, pos2.y);
 		nvgStrokeColor(vg, colorOutline);
-		nvgStrokeWidth(vg, width);
+		nvgStrokeWidth(vg, thickness);
 		nvgStroke(vg);
 
 		// Wire solid
 		nvgStrokeColor(vg, color);
-		nvgStrokeWidth(vg, width - 2);
+		nvgStrokeWidth(vg, thickness - 2);
 		nvgStroke(vg);
 
 		nvgRestore(vg);
@@ -179,17 +179,17 @@ void WireWidget::draw(NVGcontext *vg) {
 			opacity = 1.0;
 	}
 
-	float width = 5;
+	float thickness = 5;
 	if (wire && wire->outputModule) {
 		Output *output = &wire->outputModule->outputs[wire->outputId];
 		if (output->numChannels != 1) {
-			width = 8;
+			thickness = 8;
 		}
 	}
 
 	math::Vec outputPos = getOutputPos();
 	math::Vec inputPos = getInputPos();
-	drawWire(vg, outputPos, inputPos, color, width, tension, opacity);
+	drawWire(vg, outputPos, inputPos, color, thickness, tension, opacity);
 }
 
 void WireWidget::drawPlugs(NVGcontext *vg) {
diff --git a/src/engine/Module.cpp b/src/engine/Module.cpp
index 3f705aef..80004d84 100644
--- a/src/engine/Module.cpp
+++ b/src/engine/Module.cpp
@@ -21,9 +21,6 @@ void Module::setup(int numParams, int numInputs, int numOutputs, int numLights)
 json_t *Module::toJson() {
 	json_t *rootJ = json_object();
 
-	// id
-	json_object_set_new(rootJ, "id", json_integer(id));
-
 	// params
 	json_t *paramsJ = json_array();
 	for (Param &param : params) {
@@ -42,11 +39,6 @@ json_t *Module::toJson() {
 }
 
 void Module::fromJson(json_t *rootJ) {
-	// id
-	json_t *idJ = json_object_get(rootJ, "id");
-	if (idJ)
-		id = json_integer_value(idJ);
-
 	// params
 	json_t *paramsJ = json_object_get(rootJ, "params");
 	size_t i;