diff --git a/src/engine/dispatchContainer.cpp b/src/engine/dispatchContainer.cpp
index 54768f373..684984aba 100644
--- a/src/engine/dispatchContainer.cpp
+++ b/src/engine/dispatchContainer.cpp
@@ -620,11 +620,6 @@ void DivDispatchContainer::init(DivSystem sys, DivEngine* eng, int chanCount, do
       break;
     case DIV_SYSTEM_SWAN:
       dispatch=new DivPlatformSwan;
-      if (isRender) {
-        ((DivPlatformSwan*)dispatch)->setCoreQuality(eng->getConfInt("swanQualityRender",3));
-      } else {
-        ((DivPlatformSwan*)dispatch)->setCoreQuality(eng->getConfInt("swanQuality",3));
-      }
       break;
     case DIV_SYSTEM_T6W28:
       dispatch=new DivPlatformT6W28;
diff --git a/src/engine/platform/sound/swan.cpp b/src/engine/platform/sound/swan.cpp
index 685fefe94..405198a2b 100644
--- a/src/engine/platform/sound/swan.cpp
+++ b/src/engine/platform/sound/swan.cpp
@@ -49,18 +49,23 @@
    }
 
 
-#define SYNCSAMPLE(wt)	/* \
+#define SYNCSAMPLE(wt)	\
    {	\
-    int32_t left = sample_cache[ch][0], right = sample_cache[ch][1];	\
-    WaveSynth.offset_inline(wt, left - last_val[ch][0], sbuf[0]);	\
-    WaveSynth.offset_inline(wt, right - last_val[ch][1], sbuf[1]);	\
-    last_val[ch][0] = left;	\
-    last_val[ch][1] = right;	\
-   } */
+    int32_t left = sample_cache[ch][0] << 5, right = sample_cache[ch][1] << 5;	\
+    if (left!=last_val[ch][0]) { \
+      blip_add_delta(sbuf[0], wt, left - last_val[ch][0]);	\
+      last_val[ch][0] = left;	\
+    } \
+    if (right!=last_val[ch][1]) { \
+      blip_add_delta(sbuf[1], wt, right - last_val[ch][1]);	\
+      last_val[ch][1] = right;	\
+    } \
+    oscBuf[ch]->putSample(wt,(left+right)<<1); \
+   }
 
 #define SYNCSAMPLE_NOISE(wt) SYNCSAMPLE(wt)
 
-void WSwan::SoundUpdate(uint32_t v30mz_timestamp)
+void WSwan::SoundUpdate(void)
 {
  int32_t run_time;
 
@@ -68,9 +73,6 @@ void WSwan::SoundUpdate(uint32_t v30mz_timestamp)
  //printf("%02x %02x\n", control, noise_control);
  run_time = v30mz_timestamp - last_ts;
 
- for(int y = 0; y < 2; y++)
-  sbuf[y] = 0;
-
  for(unsigned int ch = 0; ch < 4; ch++)
  {
   // Channel is disabled?
@@ -85,6 +87,7 @@ void WSwan::SoundUpdate(uint32_t v30mz_timestamp)
   else if(ch == 2 && (control & 0x40) && sweep_value) // Sweep
   {
    uint32_t tmp_pt = 2048 - period[ch];
+   uint32_t meow_timestamp = v30mz_timestamp - run_time;
    uint32_t tmp_run_time = run_time;
 
    while(tmp_run_time)
@@ -106,6 +109,7 @@ void WSwan::SoundUpdate(uint32_t v30mz_timestamp)
      }
     }
 
+    meow_timestamp += sub_run_time;
     if(tmp_pt > 4)
     {
      period_counter[ch] -= sub_run_time;
@@ -114,6 +118,7 @@ void WSwan::SoundUpdate(uint32_t v30mz_timestamp)
       sample_pos[ch] = (sample_pos[ch] + 1) & 0x1F;
 
       MK_SAMPLE_CACHE;
+      SYNCSAMPLE(meow_timestamp + period_counter[ch]);
       period_counter[ch] += tmp_pt;
      }
     }
@@ -162,8 +167,6 @@ void WSwan::SoundUpdate(uint32_t v30mz_timestamp)
     }
    }
   }
-  sbuf[0] += sample_cache[ch][0];
-  sbuf[1] += sample_cache[ch][1];
  }
 
  if(HVoiceCtrl & 0x80)
@@ -181,21 +184,25 @@ void WSwan::SoundUpdate(uint32_t v30mz_timestamp)
   sample >>= 5;
 
   int32_t left, right;
-  left  = (HVoiceChanCtrl & 0x40) ? sample : 0;
-  right = (HVoiceChanCtrl & 0x20) ? sample : 0;
+  left  = (HVoiceChanCtrl & 0x40) ? (sample << 5) : 0;
+  right = (HVoiceChanCtrl & 0x20) ? (sample << 5) : 0;
 
-  // WaveSynth.offset_inline(v30mz_timestamp, left - last_hv_val[0], sbuf[0]);
-  // WaveSynth.offset_inline(v30mz_timestamp, right - last_hv_val[1], sbuf[1]);
-  // last_hv_val[0] = left;
-  // last_hv_val[1] = right;
-  sbuf[0] += left;
-  sbuf[1] += right;
+  if (left!=last_hv_val[0]) {
+    blip_add_delta(sbuf[0], v30mz_timestamp, left - last_hv_val[0]);
+    last_hv_val[0] = left;
+  }
+  if (right!=last_hv_val[1]) {
+    blip_add_delta(sbuf[1], v30mz_timestamp, right - last_hv_val[1]);
+    last_hv_val[1] = right;
+  }
  }
  last_ts = v30mz_timestamp;
 }
 
 void WSwan::SoundWrite(uint32_t A, uint8_t V)
 {
+ SoundUpdate();
+
  if(A >= 0x80 && A <= 0x87)
  {
   int ch = (A - 0x80) >> 1;
@@ -262,10 +269,13 @@ void WSwan::SoundWrite(uint32_t A, uint8_t V)
   case 0x95: HyperVoice = V; break; // Pick a port, any port?!
   //default: printf("%04x:%02x\n", A, V); break;
  }
+ SoundUpdate();
 }
 
 uint8_t WSwan::SoundRead(uint32_t A)
 {
+ SoundUpdate();
+
  if(A >= 0x80 && A <= 0x87)
  {
   int ch = (A - 0x80) >> 1;
@@ -303,22 +313,8 @@ int32_t WSwan::SoundFlush(int16_t *SoundBuf, const int32_t MaxSoundFrames)
 {
 	int32_t FrameCount = 0;
 
-	if(SoundBuf)
-	{
-	 for(int y = 0; y < 2; y++)
-	 {
-	  // sbuf[y]->end_frame(v30mz_timestamp);
-	  // FrameCount = sbuf[y]->read_samples(SoundBuf + y, MaxSoundFrames, true);
-	  int32_t left = sbuf[0];
-	  int32_t right = sbuf[1];
-	  if (left >= 0x400) left = 0x3FF;
-	  else if (left < -0x400) left = -0x400;
-	  if (right >= 0x400) left = 0x3FF;
-	  else if (right < -0x400) left = -0x400;
-	  SoundBuf[0] = (int16_t)left << 5;
-	  SoundBuf[1] = (int16_t)right << 5;
-	 }
-	}
+	SoundUpdate();
+
 
 	last_ts = 0;
 
@@ -326,51 +322,11 @@ int32_t WSwan::SoundFlush(int16_t *SoundBuf, const int32_t MaxSoundFrames)
 }
 
 // Call before wsRAM is updated
-// void WSwan::SoundCheckRAMWrite(uint32_t A)
-// {
-//  if((A >> 6) == SampleRAMPos)
-//   SoundUpdate();
-// }
-
-// static void RedoVolume(void)
-// {
-//  WaveSynth.volume(2.5);
-// }
-
-// void WSwan::SoundInit(void)
-// {
-//  for(int i = 0; i < 2; i++)
-//  {
-//   sbuf[i] = new Blip_Buffer();
-
-//   sbuf[i]->set_sample_rate(0 ? 0 : 44100, 60);
-//   sbuf[i]->clock_rate((long)(3072000));
-//   sbuf[i]->bass_freq(20);
-//  }
-
-//  RedoVolume();
-// }
-
-// void WSwan::SoundKill(void)
-// {
-//  for(int i = 0; i < 2; i++)
-//  {
-//   if(sbuf[i])
-//   {
-//    delete sbuf[i];
-//    sbuf[i] = NULL;
-//   }
-//  }
-
-// }
-
-// bool WSwan::SetSoundRate(uint32_t rate)
-// {
-//  for(int i = 0; i < 2; i++)
-//   sbuf[i]->set_sample_rate(rate?rate:44100, 60);
-
-//  return(true);
-// }
+void WSwan::SoundCheckRAMWrite(uint32_t A)
+{
+ if((A >> 6) == SampleRAMPos)
+  SoundUpdate();
+}
 
 void WSwan::SoundReset(void)
 {
@@ -394,7 +350,7 @@ void WSwan::SoundReset(void)
  nreg = 0;
 
  memset(sample_cache, 0, sizeof(sample_cache));
- // memset(last_val, 0, sizeof(last_val));
+ memset(last_val, 0, sizeof(last_val));
  last_v_val = 0;
 
  HyperVoice = 0;
@@ -402,8 +358,6 @@ void WSwan::SoundReset(void)
  HVoiceCtrl = 0;
  HVoiceChanCtrl = 0;
 
- for(int y = 0; y < 2; y++)
-  // sbuf[y]->clear();
-  sbuf[y] = 0;
  last_ts = 0;
+ v30mz_timestamp = 0;
 }
diff --git a/src/engine/platform/sound/swan.h b/src/engine/platform/sound/swan.h
index bd421a74c..32fb37a82 100644
--- a/src/engine/platform/sound/swan.h
+++ b/src/engine/platform/sound/swan.h
@@ -23,32 +23,29 @@
 #define __WSWAN_SOUND_H
 
 #include <stdint.h>
+#include "blip_buf.h"
+#include "../../dispatch.h"
 
 class WSwan
 {
 public:
  int32_t SoundFlush(int16_t *SoundBuf, const int32_t MaxSoundFrames);
 
- // void SoundInit(void);
- // void SoundKill(void);
- // void SetSoundMultiplier(double multiplier);
- // bool SetSoundRate(uint32_t rate);
-
  void SoundWrite(uint32_t, uint8_t);
  uint8_t SoundRead(uint32_t);
  void SoundReset(void);
- // void SoundCheckRAMWrite(uint32_t A);
+ void SoundCheckRAMWrite(uint32_t A);
 
- void SoundUpdate(uint32_t);
+ void SoundUpdate();
  void RAMWrite(uint32_t, uint8_t);
  
  int32_t sample_cache[4][2];
 
-private:
  // Blip_Synth<blip_good_quality, 4096> WaveSynth;
 
  // Blip_Buffer *sbuf[2] = { NULL };
- int32_t sbuf[2];
+ blip_buffer_t* sbuf[2];
+ DivDispatchOscBuffer* oscBuf[4];
 
  uint16_t period[4];
  uint8_t volume[4]; // left volume in upper 4 bits, right in lower 4 bits
@@ -70,10 +67,11 @@ private:
  uint8_t HVoiceCtrl, HVoiceChanCtrl;
 
  int32_t period_counter[4];
- // int32_t last_val[4][2]; // Last outputted value, l&r
+ int32_t last_val[4][2]; // Last outputted value, l&r
  uint8_t sample_pos[4];
  uint16_t nreg;
  uint32_t last_ts;
+ uint32_t v30mz_timestamp;
 
  uint8_t wsRAM[64];
 };
diff --git a/src/engine/platform/swan.cpp b/src/engine/platform/swan.cpp
index 338f8fd0b..a7ef3ae06 100644
--- a/src/engine/platform/swan.cpp
+++ b/src/engine/platform/swan.cpp
@@ -53,16 +53,36 @@ const char** DivPlatformSwan::getRegisterSheet() {
   return regCheatSheetWS;
 }
 
-void DivPlatformSwan::acquire(short** buf, size_t len) {
+void DivPlatformSwan::acquireDirect(blip_buffer_t** bb, size_t len) {
   for (int i=0; i<4; i++) {
     oscBuf[i]->begin(len);
+    ws->oscBuf[i]=oscBuf[i];
   }
 
+  ws->sbuf[0]=bb[0];
+  ws->sbuf[1]=bb[1];
+
   for (size_t h=0; h<len; h++) {
+    ws->v30mz_timestamp=h;
+    // heuristic
+    int pcmAdvance=1;
+    if (writes.empty()) {
+      if (!pcm || dacSample==-1) {
+        break;
+      } else {
+        pcmAdvance=len-h;
+        if (dacRate>0) {
+          int remainTime=(rate-dacPeriod+dacRate-1)/dacRate;
+          if (remainTime<pcmAdvance) pcmAdvance=remainTime;
+          if (remainTime<1) pcmAdvance=1;
+        }
+      }
+    }
+
     // PCM part
     if (pcm && dacSample!=-1) {
-      dacPeriod+=dacRate;
-      while (dacPeriod>rate) {
+      dacPeriod+=dacRate*pcmAdvance;
+      while (dacPeriod>=rate) {
         DivSample* s=parent->getSample(dacSample);
         if (s->samples<=0 || dacPos>=s->samples) {
           dacSample=-1;
@@ -78,25 +98,27 @@ void DivPlatformSwan::acquire(short** buf, size_t len) {
         dacPeriod-=rate;
       }
     }
+
+    h+=pcmAdvance-1;
   
     // the rest
     while (!writes.empty()) {
       QueuedWrite w=writes.front();
       regPool[w.addr]=w.val;
-      if (w.addr<0x40) ws->SoundWrite(w.addr|0x80,w.val);
-      else ws->RAMWrite(w.addr&0x3f,w.val);
+      if (w.addr<0x40) {
+        ws->SoundWrite(w.addr|0x80,w.val);
+      } else {
+        ws->SoundCheckRAMWrite(w.addr&0x3f);
+        ws->RAMWrite(w.addr&0x3f,w.val);
+      }
       writes.pop();
     }
-    int16_t samp[2]{0, 0};
-    ws->SoundUpdate(coreQuality);
-    ws->SoundFlush(samp,1);
-    buf[0][h]=samp[0];
-    buf[1][h]=samp[1];
-    for (int i=0; i<4; i++) {
-      oscBuf[i]->putSample(h,(ws->sample_cache[i][0]+ws->sample_cache[i][1])<<6);
-    }
   }
 
+  ws->v30mz_timestamp=len;
+  ws->SoundUpdate();
+  ws->SoundFlush(NULL,0);
+
   for (int i=0; i<4; i++) {
     oscBuf[i]->end(len);
   }
@@ -587,6 +609,10 @@ int DivPlatformSwan::getOutputCount() {
   return 2;
 }
 
+bool DivPlatformSwan::hasAcquireDirect() {
+  return true;
+}
+
 void DivPlatformSwan::notifyWaveChange(int wave) {
   for (int i=0; i<4; i++) {
     if (chan[i].wave==wave) {
@@ -613,38 +639,12 @@ void DivPlatformSwan::poke(std::vector<DivRegWrite>& wlist) {
 void DivPlatformSwan::setFlags(const DivConfig& flags) {
   chipClock=3072000;
   CHECK_CUSTOM_CLOCK;
-  rate=chipClock/coreQuality;
+  rate=chipClock;
   for (int i=0; i<4; i++) {
     oscBuf[i]->setRate(rate);
   }
 }
 
-void DivPlatformSwan::setCoreQuality(unsigned char q) {
-  switch (q) {
-    case 0:
-      coreQuality=96;
-      break;
-    case 1:
-      coreQuality=64;
-      break;
-    case 2:
-      coreQuality=32;
-      break;
-    case 3:
-      coreQuality=16;
-      break;
-    case 4:
-      coreQuality=4;
-      break;
-    case 5:
-      coreQuality=1;
-      break;
-    default:
-      coreQuality=16;
-      break;
-  }
-}
-
 int DivPlatformSwan::init(DivEngine* p, int channels, int sugRate, const DivConfig& flags) {
   parent=p;
   dumpWrites=false;
diff --git a/src/engine/platform/swan.h b/src/engine/platform/swan.h
index f65702d37..095b338aa 100644
--- a/src/engine/platform/swan.h
+++ b/src/engine/platform/swan.h
@@ -53,13 +53,12 @@ class DivPlatformSwan: public DivDispatch {
   };
   FixedQueue<QueuedWrite,256> writes;
   FixedQueue<DivRegWrite,2048> postDACWrites;
-  int coreQuality;
   WSwan* ws;
   void updateWave(int ch);
   friend void putDispatchChip(void*,int);
   friend void putDispatchChan(void*,int,int);
   public:
-    void acquire(short** buf, size_t len);
+    void acquireDirect(blip_buffer_t** bb, size_t len);
     int dispatch(DivCommand c);
     void* getChanState(int chan);
     DivMacroInt* getChanMacroInt(int ch);
@@ -76,10 +75,10 @@ class DivPlatformSwan: public DivDispatch {
     void notifyWaveChange(int wave);
     void notifyInsDeletion(void* ins);
     int getOutputCount();
+    bool hasAcquireDirect();
     void poke(unsigned int addr, unsigned short val);
     void poke(std::vector<DivRegWrite>& wlist);
     const char** getRegisterSheet();
-    void setCoreQuality(unsigned char q);
     int init(DivEngine* parent, int channels, int sugRate, const DivConfig& flags);
     void quit();
     ~DivPlatformSwan();
diff --git a/src/gui/gui.h b/src/gui/gui.h
index ae6c36b28..a4f9a4e25 100644
--- a/src/gui/gui.h
+++ b/src/gui/gui.h
@@ -1802,7 +1802,6 @@ class FurnaceGUI {
     int pnQuality;
     int saaQuality;
     int smQuality;
-    int swanQuality;
     int arcadeCoreRender;
     int ym2612CoreRender;
     int snCoreRender;
@@ -1826,7 +1825,6 @@ class FurnaceGUI {
     int pnQualityRender;
     int saaQualityRender;
     int smQualityRender;
-    int swanQualityRender;
     int pcSpeakerOutMethod;
     String yrw801Path;
     String tg100Path;
@@ -2061,7 +2059,6 @@ class FurnaceGUI {
       pnQuality(3),
       saaQuality(3),
       smQuality(3),
-      swanQuality(3),
       arcadeCoreRender(1),
       ym2612CoreRender(0),
       snCoreRender(0),
@@ -2085,7 +2082,6 @@ class FurnaceGUI {
       pnQualityRender(3),
       saaQualityRender(3),
       smQualityRender(3),
-      swanQualityRender(3),
       pcSpeakerOutMethod(0),
       yrw801Path(""),
       tg100Path(""),
diff --git a/src/gui/settings.cpp b/src/gui/settings.cpp
index 598845e21..a4efbfd14 100644
--- a/src/gui/settings.cpp
+++ b/src/gui/settings.cpp
@@ -2127,7 +2127,6 @@ void FurnaceGUI::drawSettings() {
           CORE_QUALITY("SAA1099",saaQuality,saaQualityRender);
           CORE_QUALITY("SID (dSID)",dsidQuality,dsidQualityRender);
           CORE_QUALITY("SM8521",smQuality,smQualityRender);
-          CORE_QUALITY("WonderSwan",swanQuality,swanQualityRender);
 
           ImGui::EndTable();
         }
@@ -5135,7 +5134,6 @@ void FurnaceGUI::readConfig(DivConfig& conf, FurnaceGUISettingGroups groups) {
     settings.pnQuality=conf.getInt("pnQuality",3);
     settings.saaQuality=conf.getInt("saaQuality",3);
     settings.smQuality=conf.getInt("smQuality",3);
-    settings.swanQuality=conf.getInt("swanQuality",3);
 
     settings.arcadeCoreRender=conf.getInt("arcadeCoreRender",1);
     settings.ym2612CoreRender=conf.getInt("ym2612CoreRender",0);
@@ -5161,7 +5159,6 @@ void FurnaceGUI::readConfig(DivConfig& conf, FurnaceGUISettingGroups groups) {
     settings.pnQualityRender=conf.getInt("pnQualityRender",3);
     settings.saaQualityRender=conf.getInt("saaQualityRender",3);
     settings.smQualityRender=conf.getInt("smQualityRender",3);
-    settings.swanQualityRender=conf.getInt("swanQualityRender",3);
 
     settings.pcSpeakerOutMethod=conf.getInt("pcSpeakerOutMethod",0);
 
@@ -5203,7 +5200,6 @@ void FurnaceGUI::readConfig(DivConfig& conf, FurnaceGUISettingGroups groups) {
   clampSetting(settings.pnQuality,0,5);
   clampSetting(settings.saaQuality,0,5);
   clampSetting(settings.smQuality,0,5);
-  clampSetting(settings.swanQuality,0,5);
   clampSetting(settings.arcadeCoreRender,0,1);
   clampSetting(settings.ym2612CoreRender,0,2);
   clampSetting(settings.snCoreRender,0,1);
@@ -5227,7 +5223,6 @@ void FurnaceGUI::readConfig(DivConfig& conf, FurnaceGUISettingGroups groups) {
   clampSetting(settings.pnQualityRender,0,5);
   clampSetting(settings.saaQualityRender,0,5);
   clampSetting(settings.smQualityRender,0,5);
-  clampSetting(settings.swanQualityRender,0,5);
   clampSetting(settings.pcSpeakerOutMethod,0,4);
   clampSetting(settings.mainFont,0,6);
   clampSetting(settings.patFont,0,6);
@@ -5725,7 +5720,6 @@ void FurnaceGUI::writeConfig(DivConfig& conf, FurnaceGUISettingGroups groups) {
     conf.set("pnQuality",settings.pnQuality);
     conf.set("saaQuality",settings.saaQuality);
     conf.set("smQuality",settings.smQuality);
-    conf.set("swanQuality",settings.swanQuality);
 
     conf.set("arcadeCoreRender",settings.arcadeCoreRender);
     conf.set("ym2612CoreRender",settings.ym2612CoreRender);
@@ -5751,7 +5745,6 @@ void FurnaceGUI::writeConfig(DivConfig& conf, FurnaceGUISettingGroups groups) {
     conf.set("pnQualityRender",settings.pnQualityRender);
     conf.set("saaQualityRender",settings.saaQualityRender);
     conf.set("smQualityRender",settings.smQualityRender);
-    conf.set("swanQualityRender",settings.swanQualityRender);
 
     conf.set("pcSpeakerOutMethod",settings.pcSpeakerOutMethod);
 
@@ -5811,7 +5804,6 @@ void FurnaceGUI::commitSettings() {
     settings.pnQuality!=e->getConfInt("pnQuality",3) ||
     settings.saaQuality!=e->getConfInt("saaQuality",3) ||
     settings.smQuality!=e->getConfInt("smQuality",3) ||
-    settings.swanQuality!=e->getConfInt("swanQuality",3) ||
     settings.audioQuality!=e->getConfInt("audioQuality",0) ||
     settings.audioHiPass!=e->getConfInt("audioHiPass",1)
   );