diff --git a/src/engine/platform/sound/swan.c b/src/engine/platform/sound/swan.c
index 5fce1cc6c..838bd69b2 100644
--- a/src/engine/platform/sound/swan.c
+++ b/src/engine/platform/sound/swan.c
@@ -127,12 +127,15 @@ void swan_sound_out(swan_sound_t *snd, uint16_t port, uint8_t value) {
 }
 
 static void swan_sound_subtick(swan_sound_t *snd, uint32_t cycles) {
+    // TODO: Do period counters update when a channel is inactive?
     for (int ch = 0; ch < 4; ch++) {
-        snd->period_counter[ch] += cycles;
-        uint32_t step = 2048 - snd->frequency[ch];
-        while (snd->period_counter[ch] >= step) {
-            snd->sample_index[ch] = (snd->sample_index[ch] + 1) & 0x1F;
-            snd->period_counter[ch] -= step;
+        if (snd->ch_ctrl & (1 << ch)) {
+            snd->period_counter[ch] += cycles;
+            uint32_t step = 2048 - snd->frequency[ch];
+            while (snd->period_counter[ch] >= step) {
+                snd->sample_index[ch] = (snd->sample_index[ch] + 1) & 0x1F;
+                snd->period_counter[ch] -= step;
+            }
         }
     }
 
diff --git a/src/engine/platform/swan.cpp b/src/engine/platform/swan.cpp
index 9a0c2acfc..698afb1bc 100644
--- a/src/engine/platform/swan.cpp
+++ b/src/engine/platform/swan.cpp
@@ -107,8 +107,12 @@ void DivPlatformSwan::acquire(short** buf, size_t len) {
       }
     }
 
-    buf[0][h] = ws.output_left;
-    buf[1][h] = ws.output_right;
+    if (stereo) {
+      buf[0][h] = ws.output_left;
+      buf[1][h] = ws.output_right;  
+    } else {
+      buf[0][h] = ((int)ws.output_speaker - 0x80) << 8;  
+    }
   }
 
   for (int i=0; i<4; i++) {
@@ -597,7 +601,7 @@ void DivPlatformSwan::reset() {
 }
 
 int DivPlatformSwan::getOutputCount() {
-  return 2;
+  return stereo?2:1;
 }
 
 void DivPlatformSwan::notifyWaveChange(int wave) {
@@ -627,6 +631,7 @@ void DivPlatformSwan::setFlags(const DivConfig& flags) {
   chipClock=3072000;
   CHECK_CUSTOM_CLOCK;
   rate=chipClock/128;
+  stereo=flags.getBool("stereo",false);
   for (int i=0; i<4; i++) {
     oscBuf[i]->setRate(rate);
   }
diff --git a/src/engine/platform/swan.h b/src/engine/platform/swan.h
index d4de0f061..31ef96faa 100644
--- a/src/engine/platform/swan.h
+++ b/src/engine/platform/swan.h
@@ -38,6 +38,7 @@ class DivPlatformSwan: public DivDispatch {
   Channel chan[4];
   DivDispatchOscBuffer* oscBuf[4];
   bool isMuted[4];
+  bool stereo=true;
   bool pcm, sweep, furnaceDac, setPos;
   unsigned char sampleBank, noise;
   int dacPeriod, dacRate;
diff --git a/src/gui/sysConf.cpp b/src/gui/sysConf.cpp
index fbea92ddc..60286da16 100644
--- a/src/gui/sysConf.cpp
+++ b/src/gui/sysConf.cpp
@@ -2664,7 +2664,19 @@ bool FurnaceGUI::drawSysConf(int chan, int sysPos, DivSystem type, DivConfig& fl
       }
       break;
     }
-    case DIV_SYSTEM_SWAN:
+    case DIV_SYSTEM_SWAN: {
+      bool stereo=flags.getBool("stereo",true);
+      if (ImGui::Checkbox(_("Headphone output##_SWAN_STEREO"),&stereo)) {
+        altered=true;
+      }
+
+      if (altered) {
+        e->lockSave([&]() {
+          flags.set("stereo",stereo);
+        });
+      }
+      break;
+    }
     case DIV_SYSTEM_BUBSYS_WSG:
     case DIV_SYSTEM_PET:
     case DIV_SYSTEM_GA20: