diff --git a/src/engine/dispatch.h b/src/engine/dispatch.h
index b4394f608..5a1c2db64 100644
--- a/src/engine/dispatch.h
+++ b/src/engine/dispatch.h
@@ -319,6 +319,18 @@ class DivDispatch {
      */
     virtual int getPortaFloor(int ch);
 
+    /**
+     * get the required amplification level of this dispatch's output.
+     * @return the amplification level.
+     */
+    virtual float getPostAmp();
+
+    /**
+     * check whether DC offset correction is required.
+     * @return truth.
+     */
+    virtual bool getDCOffRequired();
+
     /**
      * get a description of a dispatch-specific effect.
      * @param effect the effect.
diff --git a/src/engine/dispatchContainer.cpp b/src/engine/dispatchContainer.cpp
index ba72a6957..c89a0fa06 100644
--- a/src/engine/dispatchContainer.cpp
+++ b/src/engine/dispatchContainer.cpp
@@ -79,6 +79,11 @@ void DivDispatchContainer::flush(size_t count) {
 }
 
 void DivDispatchContainer::fillBuf(size_t runtotal, size_t offset, size_t size) {
+  if (dcOffCompensation && runtotal>0) {
+    dcOffCompensation=false;
+    prevSample[0]=bbIn[0][0];
+    if (dispatch->isStereo()) prevSample[1]=bbIn[1][0];
+  }
   if (lowQuality) {
     for (size_t i=0; i<runtotal; i++) {
       temp[0]=bbIn[0][i];
@@ -126,6 +131,9 @@ void DivDispatchContainer::clear() {
   temp[1]=0;
   prevSample[0]=0;
   prevSample[1]=0;
+  if (dispatch->getDCOffRequired()) {
+    dcOffCompensation=true;
+  }
   // run for one cycle to determine DC offset
   // TODO: SAA1099 doesn't like that
   /*dispatch->acquire(bbIn[0],bbIn[1],0,1);
diff --git a/src/engine/engine.h b/src/engine/engine.h
index 68ec0ce5b..c359da253 100644
--- a/src/engine/engine.h
+++ b/src/engine/engine.h
@@ -154,7 +154,7 @@ struct DivDispatchContainer {
   int temp[2], prevSample[2];
   short* bbIn[2];
   short* bbOut[2];
-  bool lowQuality;
+  bool lowQuality, dcOffCompensation;
 
   void setRates(double gotRate);
   void setQuality(bool lowQual);
@@ -172,7 +172,8 @@ struct DivDispatchContainer {
     prevSample{0,0},
     bbIn{NULL,NULL},
     bbOut{NULL,NULL},
-    lowQuality(false) {}
+    lowQuality(false),
+    dcOffCompensation(false) {}
 };
 
 class DivEngine {
diff --git a/src/engine/platform/abstract.cpp b/src/engine/platform/abstract.cpp
index 7b6115aef..b860f6808 100644
--- a/src/engine/platform/abstract.cpp
+++ b/src/engine/platform/abstract.cpp
@@ -74,6 +74,14 @@ int DivDispatch::getPortaFloor(int ch) {
   return 0x00;
 }
 
+float DivDispatch::getPostAmp() {
+  return 1.0f;
+}
+
+bool DivDispatch::getDCOffRequired() {
+  return false;
+}
+
 const char* DivDispatch::getEffectName(unsigned char effect) {
   return NULL;
 }
diff --git a/src/engine/platform/ay.cpp b/src/engine/platform/ay.cpp
index b798cba4e..e174e345b 100644
--- a/src/engine/platform/ay.cpp
+++ b/src/engine/platform/ay.cpp
@@ -497,6 +497,10 @@ void DivPlatformAY8910::flushWrites() {
   while (!writes.empty()) writes.pop();
 }
 
+bool DivPlatformAY8910::getDCOffRequired() {
+  return true;
+}
+
 void DivPlatformAY8910::reset() {
   while (!writes.empty()) writes.pop();
   ay->device_reset();
diff --git a/src/engine/platform/ay.h b/src/engine/platform/ay.h
index 82b647f2d..b1a3ea127 100644
--- a/src/engine/platform/ay.h
+++ b/src/engine/platform/ay.h
@@ -95,6 +95,7 @@ class DivPlatformAY8910: public DivDispatch {
     void setFlags(unsigned int flags);
     bool isStereo();
     bool keyOffAffectsArp(int ch);
+    bool getDCOffRequired();
     void notifyInsDeletion(void* ins);
     void poke(unsigned int addr, unsigned short val);
     void poke(std::vector<DivRegWrite>& wlist);
diff --git a/src/engine/platform/mmc5.cpp b/src/engine/platform/mmc5.cpp
index 3ccf95499..102d6a2e9 100644
--- a/src/engine/platform/mmc5.cpp
+++ b/src/engine/platform/mmc5.cpp
@@ -89,7 +89,6 @@ void DivPlatformMMC5::acquire(short* bufL, short* bufR, size_t start, size_t len
     if (!isMuted[2]) {
       sample+=mmc5->pcm.output*2;
     }
-    sample=(sample-128)<<6;
     if (sample>32767) sample=32767;
     if (sample<-32768) sample=-32768;
     bufL[i]=sample;
@@ -336,6 +335,10 @@ int DivPlatformMMC5::getRegisterPoolSize() {
   return 32;
 }
 
+float DivPlatformMMC5::getPostAmp() {
+  return 64.0f;
+}
+
 void DivPlatformMMC5::reset() {
   for (int i=0; i<3; i++) {
     chan[i]=DivPlatformMMC5::Channel();
diff --git a/src/engine/platform/mmc5.h b/src/engine/platform/mmc5.h
index a29ffc7d4..6b364d5ad 100644
--- a/src/engine/platform/mmc5.h
+++ b/src/engine/platform/mmc5.h
@@ -74,6 +74,7 @@ class DivPlatformMMC5: public DivDispatch {
     void tick();
     void muteChannel(int ch, bool mute);
     bool keyOffAffectsArp(int ch);
+    float getPostAmp();
     void setFlags(unsigned int flags);
     void notifyInsDeletion(void* ins);
     void poke(unsigned int addr, unsigned short val);
diff --git a/src/engine/platform/nes.cpp b/src/engine/platform/nes.cpp
index f61ed4fb6..9dbf55543 100644
--- a/src/engine/platform/nes.cpp
+++ b/src/engine/platform/nes.cpp
@@ -80,7 +80,14 @@ void DivPlatformNES::acquire(short* bufL, short* bufR, size_t start, size_t len)
         DivSample* s=parent->getSample(dacSample);
         if (s->samples>0) {
           if (!isMuted[4]) {
-            rWrite(0x4011,((unsigned char)s->data8[dacPos]+0x80)>>1);
+            unsigned char next=((unsigned char)s->data8[dacPos]+0x80)>>1;
+            if (dacAntiClickOn && dacAntiClick<next) {
+              dacAntiClick+=8;
+              rWrite(0x4011,dacAntiClick);
+            } else {
+              dacAntiClickOn=false;
+              rWrite(0x4011,next);
+            }
           }
           if (++dacPos>=s->samples) {
             if (s->loopStart>=0 && s->loopStart<(int)s->samples) {
@@ -101,7 +108,7 @@ void DivPlatformNES::acquire(short* bufL, short* bufR, size_t start, size_t len)
     if (nes->apu.clocked) {
       nes->apu.clocked=false;
     }
-    int sample=(pulse_output(nes)+tnd_output(nes)-128)<<7;
+    int sample=(pulse_output(nes)+tnd_output(nes));
     if (sample>32767) sample=32767;
     if (sample<-32768) sample=-32768;
     bufL[i]=sample;
@@ -454,6 +461,10 @@ int DivPlatformNES::getRegisterPoolSize() {
   return 32;
 }
 
+float DivPlatformNES::getPostAmp() {
+  return 128.0f;
+}
+
 void DivPlatformNES::reset() {
   for (int i=0; i<5; i++) {
     chan[i]=DivPlatformNES::Channel();
@@ -476,6 +487,9 @@ void DivPlatformNES::reset() {
   rWrite(0x4015,0x1f);
   rWrite(0x4001,chan[0].sweep);
   rWrite(0x4005,chan[1].sweep);
+
+  dacAntiClickOn=true;
+  dacAntiClick=0;
 }
 
 bool DivPlatformNES::keyOffAffectsArp(int ch) {
diff --git a/src/engine/platform/nes.h b/src/engine/platform/nes.h
index c1b699bcf..1dbb4411b 100644
--- a/src/engine/platform/nes.h
+++ b/src/engine/platform/nes.h
@@ -54,10 +54,11 @@ class DivPlatformNES: public DivDispatch {
   Channel chan[5];
   bool isMuted[5];
   int dacPeriod, dacRate;
-  unsigned int dacPos;
+  unsigned int dacPos, dacAntiClick;
   int dacSample;
   unsigned char sampleBank;
   unsigned char apuType;
+  bool dacAntiClickOn;
   struct NESAPU* nes;
   unsigned char regPool[128];
 
@@ -74,6 +75,7 @@ class DivPlatformNES: public DivDispatch {
     void tick();
     void muteChannel(int ch, bool mute);
     bool keyOffAffectsArp(int ch);
+    float getPostAmp();
     void setFlags(unsigned int flags);
     void notifyInsDeletion(void* ins);
     void poke(unsigned int addr, unsigned short val);
diff --git a/src/engine/platform/saa.cpp b/src/engine/platform/saa.cpp
index 0bafaf157..49adf5b13 100644
--- a/src/engine/platform/saa.cpp
+++ b/src/engine/platform/saa.cpp
@@ -414,6 +414,16 @@ void DivPlatformSAA1099::reset() {
 
   extMode=false;
 
+  rWrite(8,255);
+  rWrite(9,255);
+  rWrite(10,255);
+  rWrite(11,255);
+  rWrite(12,255);
+  rWrite(13,255);
+  rWrite(16,0x77);
+  rWrite(17,0x77);
+  rWrite(18,0x77);
+  rWrite(0x1c,2);
   rWrite(0x1c,1);
 }
 
diff --git a/src/engine/platform/sound/nes/apu.c b/src/engine/platform/sound/nes/apu.c
index 8d53e583c..9e177a780 100644
--- a/src/engine/platform/sound/nes/apu.c
+++ b/src/engine/platform/sound/nes/apu.c
@@ -213,7 +213,8 @@ void apu_turn_on(struct NESAPU* a, BYTE apu_type) {
 	a->S2.sweep.delay = 1;
 	a->S2.sweep.divider = 1;
 	a->TR.frequency = 1;
-	a->TR.sequencer = 0;
+  /* questo era 0 ma produce click nell'audio */
+	a->TR.sequencer = 7;
 	a->NS.frequency = 1;
 	a->NS.shift = 1;
 	a->DMC.frequency = 1;
diff --git a/src/engine/playback.cpp b/src/engine/playback.cpp
index 4a5cc6465..0118acc42 100644
--- a/src/engine/playback.cpp
+++ b/src/engine/playback.cpp
@@ -1863,6 +1863,8 @@ void DivEngine::nextBuf(float** in, float** out, int inChans, int outChans, unsi
   for (int i=0; i<song.systemLen; i++) {
     float volL=((float)song.systemVol[i]/64.0f)*((float)MIN(127,127-(int)song.systemPan[i])/127.0f)*song.masterVol;
     float volR=((float)song.systemVol[i]/64.0f)*((float)MIN(127,127+(int)song.systemPan[i])/127.0f)*song.masterVol;
+    volL*=disCont[i].dispatch->getPostAmp();
+    volR*=disCont[i].dispatch->getPostAmp();
     if (disCont[i].dispatch->isStereo()) {
       for (size_t j=0; j<size; j++) {
         out[0][j]+=((float)disCont[i].bbOut[0][j]/32768.0)*volL;
diff --git a/src/gui/osc.cpp b/src/gui/osc.cpp
index eb9a7b8c9..9a1c6affe 100644
--- a/src/gui/osc.cpp
+++ b/src/gui/osc.cpp
@@ -97,15 +97,20 @@ void FurnaceGUI::drawOsc() {
       minArea.y+size.y
     );
     ImRect rect=ImRect(minArea,maxArea);
+    ImRect inRect=rect;
+    inRect.Min.x+=dpiScale;
+    inRect.Min.y+=dpiScale;
+    inRect.Max.x-=dpiScale;
+    inRect.Max.y-=dpiScale;
     ImGuiStyle& style=ImGui::GetStyle();
     ImU32 color=ImGui::GetColorU32(isClipping?uiColors[GUI_COLOR_OSC_WAVE_PEAK]:uiColors[GUI_COLOR_OSC_WAVE]);
     ImU32 borderColor=ImGui::GetColorU32(uiColors[GUI_COLOR_OSC_BORDER]);
+    ImU32 refColor=ImGui::GetColorU32(uiColors[GUI_COLOR_OSC_REF]);
     ImGui::ItemSize(size,style.FramePadding.y);
     if (ImGui::ItemAdd(rect,ImGui::GetID("wsDisplay"))) {
       // https://github.com/ocornut/imgui/issues/3710
-      // TODO: improve
       const int v0 = dl->VtxBuffer.Size;
-      dl->AddRectFilled(rect.Min,rect.Max,0xffffffff,8.0f*dpiScale);
+      dl->AddRectFilled(inRect.Min,inRect.Max,0xffffffff,8.0f*dpiScale);
       const int v1 = dl->VtxBuffer.Size;
 
       for (int i=v0; i<v1; i++) {
@@ -137,9 +142,22 @@ void FurnaceGUI::drawOsc() {
         col0.z+=(col1.z-col0.z)*shadeY;
         col0.w+=(col1.w-col0.w)*shadeY;
 
+        ImVec4 conv=ImGui::ColorConvertU32ToFloat4(v->col);
+        col0.x*=conv.x;
+        col0.y*=conv.y;
+        col0.z*=conv.z;
+        col0.w*=conv.w;
+
         v->col=ImGui::ColorConvertFloat4ToU32(col0);
       }
 
+      dl->AddLine(
+        ImLerp(rect.Min,rect.Max,ImVec2(0.0f,0.5f)),
+        ImLerp(rect.Min,rect.Max,ImVec2(0.0f,0.5f)),
+        refColor,
+        dpiScale
+      );
+
       for (size_t i=0; i<512; i++) {
         float x=(float)i/512.0f;
         float y=oscValues[i]*oscZoom;
@@ -148,7 +166,7 @@ void FurnaceGUI::drawOsc() {
         waveform[i]=ImLerp(rect.Min,rect.Max,ImVec2(x,0.5f-y));
       }
       dl->AddPolyline(waveform,512,color,ImDrawFlags_None,dpiScale);
-      dl->AddRect(rect.Min,rect.Max,borderColor,8.0f*dpiScale,0,dpiScale);
+      dl->AddRect(rect.Min,rect.Max,borderColor,8.0f*dpiScale,0,2.0f*dpiScale);
     }
     if (ImGui::IsItemClicked(ImGuiMouseButton_Right)) {
       oscZoomSlider=!oscZoomSlider;