diff --git a/src/engine/platform/fmshared_OPN.h b/src/engine/platform/fmshared_OPN.h
index 610e6160..e24b9cb3 100644
--- a/src/engine/platform/fmshared_OPN.h
+++ b/src/engine/platform/fmshared_OPN.h
@@ -146,6 +146,8 @@ class DivPlatformOPN: public DivPlatformFMBase {
         pan(3) {}
     };
 
+    const int extChanOffs, psgChanOffs, adpcmAChanOffs, adpcmBChanOffs, chanNum;
+
     double fmFreqBase;
     unsigned int fmDivBase;
     unsigned int ayDiv;
@@ -157,8 +159,13 @@ class DivPlatformOPN: public DivPlatformFMBase {
 
     friend void putDispatchChip(void*,int);
     friend void putDispatchChan(void*,int,int);
-    DivPlatformOPN(double f=9440540.0, unsigned int d=72, unsigned int a=32, bool isExtSys=false, unsigned char cc=255):
+    DivPlatformOPN(int ext, int psg, int adpcmA, int adpcmB, int chanCount, double f=9440540.0, unsigned int d=72, unsigned int a=32, bool isExtSys=false, unsigned char cc=255):
       DivPlatformFMBase(),
+      extChanOffs(ext),
+      psgChanOffs(psg),
+      adpcmAChanOffs(adpcmA),
+      adpcmBChanOffs(adpcmB),
+      chanNum(chanCount),
       fmFreqBase(f),
       fmDivBase(d),
       ayDiv(a),
diff --git a/src/engine/platform/genesis.h b/src/engine/platform/genesis.h
index 1b017922..2a7b2c8d 100644
--- a/src/engine/platform/genesis.h
+++ b/src/engine/platform/genesis.h
@@ -126,7 +126,7 @@ class DivPlatformGenesis: public DivPlatformOPN {
     int init(DivEngine* parent, int channels, int sugRate, const DivConfig& flags);
     void quit();
     DivPlatformGenesis():
-      DivPlatformOPN(9440540.0, 72, 32, false, 7) {}
+      DivPlatformOPN(2, 6, 6, 6, 6, 9440540.0, 72, 32, false, 7) {}
     ~DivPlatformGenesis();
 };
 #endif
diff --git a/src/engine/platform/ym2203.h b/src/engine/platform/ym2203.h
index 2a3f292f..0e0da7e4 100644
--- a/src/engine/platform/ym2203.h
+++ b/src/engine/platform/ym2203.h
@@ -77,7 +77,7 @@ class DivPlatformYM2203: public DivPlatformOPN {
     int init(DivEngine* parent, int channels, int sugRate, const DivConfig& flags);
     void quit();
     DivPlatformYM2203():
-      DivPlatformOPN(4720270.0, 36, 16),
+      DivPlatformOPN(2, 3, 6, 6, 6, 4720270.0, 36, 16),
       prescale(0x2d) {}
     ~DivPlatformYM2203();
 };
diff --git a/src/engine/platform/ym2608.h b/src/engine/platform/ym2608.h
index f6dfc21a..d1100ce9 100644
--- a/src/engine/platform/ym2608.h
+++ b/src/engine/platform/ym2608.h
@@ -97,7 +97,7 @@ class DivPlatformYM2608: public DivPlatformOPN {
     int init(DivEngine* parent, int channels, int sugRate, const DivConfig& flags);
     void quit();
     DivPlatformYM2608():
-      DivPlatformOPN(9440540.0, 72, 32),
+      DivPlatformOPN(2, 6, 9, 15, 16, 9440540.0, 72, 32),
       prescale(0x2d) {}
     ~DivPlatformYM2608();
 };
diff --git a/src/engine/platform/ym2610.cpp b/src/engine/platform/ym2610.cpp
index 5aa13499..2a3b00ac 100644
--- a/src/engine/platform/ym2610.cpp
+++ b/src/engine/platform/ym2610.cpp
@@ -1275,7 +1275,7 @@ bool DivPlatformYM2610::keyOffAffectsArp(int ch) {
 }
 
 void DivPlatformYM2610::notifyInsChange(int ins) {
-  for (int i=0; i<chanNum; i++) {
+  for (int i=0; i<16; i++) {
     if (chan[i].ins==ins) {
       chan[i].insChanged=true;
     }
diff --git a/src/engine/platform/ym2610.h b/src/engine/platform/ym2610.h
index 084a150c..b07819f0 100644
--- a/src/engine/platform/ym2610.h
+++ b/src/engine/platform/ym2610.h
@@ -22,7 +22,7 @@
 
 #include "ym2610shared.h"
 
-class DivPlatformYM2610: public DivPlatformYM2610Base<14> {
+class DivPlatformYM2610: public DivPlatformYM2610Base {
   protected:
     const unsigned short chanOffs[4]={
       0x01, 0x02, 0x101, 0x102
@@ -60,7 +60,7 @@ class DivPlatformYM2610: public DivPlatformYM2610Base<14> {
     int init(DivEngine* parent, int channels, int sugRate, const DivConfig& flags);
     void quit();
     DivPlatformYM2610():
-      DivPlatformYM2610Base<14>(1,4,7,13) {}
+      DivPlatformYM2610Base(1,4,7,13,14) {}
     ~DivPlatformYM2610();
 };
 #endif
diff --git a/src/engine/platform/ym2610b.cpp b/src/engine/platform/ym2610b.cpp
index 00adbdd1..28c69353 100644
--- a/src/engine/platform/ym2610b.cpp
+++ b/src/engine/platform/ym2610b.cpp
@@ -1342,7 +1342,7 @@ bool DivPlatformYM2610B::keyOffAffectsArp(int ch) {
 }
 
 void DivPlatformYM2610B::notifyInsChange(int ins) {
-  for (int i=0; i<chanNum; i++) {
+  for (int i=0; i<16; i++) {
     if (chan[i].ins==ins) {
       chan[i].insChanged=true;
     }
diff --git a/src/engine/platform/ym2610b.h b/src/engine/platform/ym2610b.h
index 40b78927..26a5cdee 100644
--- a/src/engine/platform/ym2610b.h
+++ b/src/engine/platform/ym2610b.h
@@ -22,7 +22,7 @@
 
 #include "ym2610shared.h"
 
-class DivPlatformYM2610B: public DivPlatformYM2610Base<16> {
+class DivPlatformYM2610B: public DivPlatformYM2610Base {
   protected:
     const unsigned short chanOffs[6]={
       0x00, 0x01, 0x02, 0x100, 0x101, 0x102
@@ -56,7 +56,7 @@ class DivPlatformYM2610B: public DivPlatformYM2610Base<16> {
     int init(DivEngine* parent, int channels, int sugRate, const DivConfig& flags);
     void quit();
     DivPlatformYM2610B():
-      DivPlatformYM2610Base<16>(2,6,9,15) {}
+      DivPlatformYM2610Base(2,6,9,15,16) {}
     ~DivPlatformYM2610B();
 };
 #endif
diff --git a/src/engine/platform/ym2610shared.h b/src/engine/platform/ym2610shared.h
index 487412d5..79dde4ab 100644
--- a/src/engine/platform/ym2610shared.h
+++ b/src/engine/platform/ym2610shared.h
@@ -44,11 +44,11 @@ class DivYM2610Interface: public ymfm::ymfm_interface {
       sampleBank(0) {}
 };
 
-template<int ChanNum> class DivPlatformYM2610Base: public DivPlatformOPN {
+class DivPlatformYM2610Base: public DivPlatformOPN {
   protected:
-    OPNChannelStereo chan[ChanNum];
-    DivDispatchOscBuffer* oscBuf[ChanNum];
-    bool isMuted[ChanNum];
+    OPNChannelStereo chan[16];
+    DivDispatchOscBuffer* oscBuf[16];
+    bool isMuted[16];
 
     ymfm::ym2610b* fm;
     ymfm::ym2610b::output_data fmout;
@@ -72,9 +72,6 @@ template<int ChanNum> class DivPlatformYM2610Base: public DivPlatformOPN {
     unsigned char writeADPCMAOff, writeADPCMAOn;
     int globalADPCMAVolume;
 
-    const int extChanOffs, psgChanOffs, adpcmAChanOffs, adpcmBChanOffs;
-    const int chanNum=ChanNum;
-
     double NOTE_OPNB(int ch, int note) {
       if (ch>=adpcmBChanOffs) { // ADPCM
         return NOTE_ADPCMB(note);
@@ -221,7 +218,7 @@ template<int ChanNum> class DivPlatformYM2610Base: public DivPlatformOPN {
       CHECK_CUSTOM_CLOCK;
       noExtMacros=flags.getBool("noExtMacros",false);
       rate=chipClock/16;
-      for (int i=0; i<ChanNum; i++) {
+      for (int i=0; i<16; i++) {
         oscBuf[i]->rate=rate;
       }
     }
@@ -231,7 +228,7 @@ template<int ChanNum> class DivPlatformYM2610Base: public DivPlatformOPN {
       ayFlags.set("chipType",1);
       dumpWrites=false;
       skipRegisterWrites=false;
-      for (int i=0; i<ChanNum; i++) {
+      for (int i=0; i<16; i++) {
         isMuted[i]=false;
         oscBuf[i]=new DivDispatchOscBuffer;
       }
@@ -253,7 +250,7 @@ template<int ChanNum> class DivPlatformYM2610Base: public DivPlatformOPN {
     }
 
     void quit() {
-      for (int i=0; i<ChanNum; i++) {
+      for (int i=0; i<16; i++) {
         delete oscBuf[i];
       }
       ay->quit();
@@ -262,12 +259,8 @@ template<int ChanNum> class DivPlatformYM2610Base: public DivPlatformOPN {
       delete[] adpcmBMem;
     }
 
-    DivPlatformYM2610Base(int ext, int psg, int adpcmA, int adpcmB):
-      DivPlatformOPN(9440540.0, 72, 32),
-      extChanOffs(ext),
-      psgChanOffs(psg),
-      adpcmAChanOffs(adpcmA),
-      adpcmBChanOffs(adpcmB) {}
+    DivPlatformYM2610Base(int ext, int psg, int adpcmA, int adpcmB, int chanCount):
+      DivPlatformOPN(ext,psg,adpcmA,adpcmB,chanCount,9440540.0, 72, 32) {}
 };
 
 #endif
diff --git a/src/gui/debug.cpp b/src/gui/debug.cpp
index 3a9ff950..5a612382 100644
--- a/src/gui/debug.cpp
+++ b/src/gui/debug.cpp
@@ -65,7 +65,11 @@
   FM_CHIP_DEBUG; \
   ImGui::Text("- fmFreqBase: %.f",ch->fmFreqBase); \
   ImGui::Text("- fmDivBase: %d",ch->fmDivBase); \
-  ImGui::Text("- ayDiv: %d",ch->ayDiv);
+  ImGui::Text("- ayDiv: %d",ch->ayDiv); \
+  ImGui::Text("- extChanOffs: %d",ch->extChanOffs); \
+  ImGui::Text("- psgChanOffs: %d",ch->psgChanOffs); \
+  ImGui::Text("- adpcmAChanOffs: %d",ch->adpcmAChanOffs); \
+  ImGui::Text("- adpcmBChanOffs: %d",ch->adpcmBChanOffs); \
 
 #define COMMON_CHIP_DEBUG_BOOL \
   ImGui::TextColored(ch->skipRegisterWrites?colorOn:colorOff,">> SkipRegisterWrites"); \
@@ -97,11 +101,6 @@
   ImGui::Text("- writeADPCMAOff: %d",ch->writeADPCMAOff); \
   ImGui::Text("- writeADPCMAOn: %d",ch->writeADPCMAOn); \
   ImGui::Text("- globalADPCMAVolume: %d",ch->globalADPCMAVolume); \
-  ImGui::Text("- extChanOffs: %d",ch->extChanOffs); \
-  ImGui::Text("- psgChanOffs: %d",ch->psgChanOffs); \
-  ImGui::Text("- adpcmAChanOffs: %d",ch->adpcmAChanOffs); \
-  ImGui::Text("- adpcmBChanOffs: %d",ch->adpcmBChanOffs); \
-  ImGui::Text("- chanNum: %d",ch->chanNum); \
   FM_OPN_CHIP_DEBUG_BOOL; \
   ImGui::TextColored(ch->extMode?colorOn:colorOff,">> ExtMode");