If a source is powered down zero its outputs

Since otherwise you get remnants when you toggle power

Author: baconpaul

src/dsp/op_source.h

@@ -123,6 +123,8 @@ struct alignas(16) OpSource : public EnvelopeSupport<Patch::SourceNode>,
         rmAssigned = false;
     }
 
+    void clearOutputs() { memset(output, 0, sizeof(output)); }
+
     void snapActive() { active = activeV > 0.5; }
 
     float baseFrequency{0};

src/synth/voice.cpp

@@ -87,6 +87,7 @@ void Voice::renderBlock()
     {
         if (!src[i].active)
         {
+            src[i].clearOutputs();
             continue;
         }
         src[i].zeroInputs();