diff --git a/plugin/chorus.cpp b/plugin/chorus.cpp
index d181c6c..06b4f92 100644
--- a/plugin/chorus.cpp
+++ b/plugin/chorus.cpp
@@ -29,8 +29,8 @@ Chorus::Chorus() {
     lfoPhase = 1;
     lfoSpeed = 6.283 * 10.7 / sampleRate;  // plainly silly value to show if it hasn't been set
 
-    gainTC = 1 - exp(-6.283 * 10 / sampleRate);  // 1/10th of a second declick
-    bbdTC = 1 - exp(-6.283 * 30 / sampleRate);   // hpf into BBD at 159Hz
+    gainTC = 1 - exp(-M_PI * 10 / sampleRate);  // 1/10th of a second declick
+    bbdTC = 1 - exp(-M_PI * 60 / sampleRate);   // hpf into BBD 
 
     // not quite Butterworth but you'd never hear the difference
     // these are calculated from the real-world component values
@@ -127,11 +127,11 @@ void Chorus::setHpf(uint8_t mode) {
     // k = 1-exp(-2pi * Fc * sampleRate)
     switch (mode) {
         case 0x00:
-            hpCut = 1 - exp(-6.283 * 720 / sampleRate);
+            hpCut = 1 - exp(-M_PI * 720 / sampleRate);
             hpGain = -1;
             break;
         case 0x08:
-            hpCut = 1 - exp(-6.283 * 225 / sampleRate);
+            hpCut = 1 - exp(-M_PI * 225 / sampleRate);
             hpGain = -1;
             break;
         case 0x10:
@@ -139,7 +139,7 @@ void Chorus::setHpf(uint8_t mode) {
             hpGain = 0;
             break;
         case 0x18:
-            hpCut = 1 - exp(-6.283 * 85 / sampleRate);
+            hpCut = 1 - exp(-M_PI * 85 / sampleRate);
             hpGain = 1.707;
             break;
     }
@@ -154,11 +154,11 @@ void Chorus::setChorus(uint8_t mode) {
             break;
         case 0x40:
             gain = 1.2;
-            lfoSpeed = 6.283 * 0.525 / sampleRate / 2;
+            lfoSpeed = M_PI * 0.525 / sampleRate;
             break;
         case 0x00:
             gain = 1.2;
-            lfoSpeed = 6.283 * 0.85 / sampleRate / 2;
+            lfoSpeed = M_PI * 0.85 / sampleRate;
             break;
     }
 }
diff --git a/plugin/module.cpp b/plugin/module.cpp
index c174ec9..6f55c87 100644
--- a/plugin/module.cpp
+++ b/plugin/module.cpp
@@ -25,9 +25,9 @@
 
 Module::Module() {
     // cutoff frequencies for various RC networks
-    vcaTC = 1 - exp(-6.283 * 159 / sampleRate);  // VCA and VCF 10k/0.1u time constant
-    subTC = 1 - exp(-6.283 * 15 / sampleRate);   // Main VCA and Sub Level 1k + 10u time constant
-    pwmTC = 1 - exp(-6.283 * 40 / sampleRate);   // integrator with 100k/0.047u time constant
+    vcaTC = 1 - exp(-M_PI * 159 / sampleRate);  // VCA and VCF 10k/0.1u time constant
+    subTC = 1 - exp(-M_PI * 15 / sampleRate);   // Main VCA and Sub Level 1k + 10u time constant
+    pwmTC = 1 - exp(-M_PI * 40 / sampleRate);   // integrator with 100k/0.047u time constant
 
     vcaBuf = new float[bufferSize];
     subBuf = new float[bufferSize];
@@ -104,12 +104,12 @@ void Module::run(Voice* voices, uint32_t blockSize) {
     // originally I had 0.28, 0.36, 0.4
     // measurement suggests that saw and square are around 100mV each with sub 160mV
 
-    square = (patchRam.switch1 & 0x08) ? 0.3 : 0;
-    saw = (patchRam.switch1 & 0x10) ? .3 : 0;
-    sub = (patchRam.sub / 127.0f) * 0.48;
+    square = (patchRam.switch1 & 0x08) ? 1 : 0;
+    saw = (patchRam.switch1 & 0x10) ? 1 : 0;
+    sub = (patchRam.sub / 127.0f) * 1.6;
 
     res = patchRam.vcfReso / 127.0;
-    noise = (patchRam.noise / 127.0) * 0.4;
+    noise = (patchRam.noise / 127.0);
 
     // FIXME the exp in these is expensive, don't call it all the time
     chorus->setChorus(patchRam.switch1 & 0x60);
@@ -183,7 +183,7 @@ void Module::run(Voice* voices, uint32_t blockSize) {
         v->omega = px / (sampleRate * 8.0f);  // FIXME recalculate table using proper scaler
 
         // per voice we need to calculate the key follow amount and envelope amount
-        v->vcfCut = vcfBase + (((v->env * patchRam.vcfEnv)>>7) * ((patchRam.switch1 & 0x02) ? -1 : 1));
+        v->vcfCut = vcfBase + (((v->env * patchRam.vcfEnv)>>7) * ((patchRam.switch2 & 0x02) ? -1 : 1));
 
         v->vcfCut += (int)((v->note - 36) * (patchRam.vcfKey << 1) * 0.375);
 
diff --git a/plugin/voice.cpp b/plugin/voice.cpp
index 92ecf8f..918cd46 100644
--- a/plugin/voice.cpp
+++ b/plugin/voice.cpp
@@ -72,7 +72,7 @@ void Voice::run(Module* m, float* buffer, uint32_t framePos, uint32_t samples) {
 
     float r = 5 * m->res;
 
-    float amp = vcaEnv / 4096.0f;
+    float amp = vcaEnv / 16384.0f;
 
     for (uint32_t i = 0; i < samples; i++) {
         out = delay;