diff --git a/MicroMDAEPiano.ino b/MicroMDAEPiano.ino
index d4fe8bc..96c46d3 100644
--- a/MicroMDAEPiano.ino
+++ b/MicroMDAEPiano.ino
@@ -227,22 +227,22 @@ void setup()
   Serial.print(audio_block_time_us);
   Serial.println(F("ms)"));
 
-  /*
-    if (!modchorus_r.begin(r_delayline, CHORUS_DELAY_LENGTH)) {
-      Serial.println(F("AudioEffectModulatedDelay - right channel begin failed"));
-      while (1);
-    }
-    if (!modchorus_l.begin(l_delayline, CHORUS_DELAY_LENGTH)) {
-      Serial.println(F("AudioEffectModulatedDelay - left channel begin failed"));
-      while (1);
-    }
+  if (!modchorus_r.begin(r_delayline, CHORUS_DELAY_LENGTH)) {
+    Serial.println(F("AudioEffectModulatedDelay - right channel begin failed"));
+    while (1);
+  }
+  if (!modchorus_l.begin(l_delayline, CHORUS_DELAY_LENGTH)) {
+    Serial.println(F("AudioEffectModulatedDelay - left channel begin failed"));
+    while (1);
+  }
 
-    // chorus modulation fixed
-    modulator.begin(CHORUS_WAVEFORM);
-    modulator.amplitude(0.1);
-    modulator.frequency(1.0);
-    modulator.phase(0);
-  */
+  // chorus modulation fixed
+  modulator.begin(CHORUS_WAVEFORM);
+  modulator.amplitude(1.0);
+  modulator.frequency(1.0);
+  modulator.phase(0);
+  modulator.offset(0.0);
+  
   // internal mixing of original signal(0), reverb(1) and chorus(2)
   mixer_r.gain(0, 1.0);
   mixer_l.gain(0, 1.0);
diff --git a/config.h b/config.h
index c171b99..a6718a9 100644
--- a/config.h
+++ b/config.h
@@ -62,7 +62,7 @@
 #define USE_XFADE_DATA 1
 // CHORUS parameters
 #define INTERPOLATION_WINDOW_SIZE 7 // For chorus, only odd numbers,please!
-#define INTERPOLATE LAGRANGE // LINEAR QUADRATIC COSINE CUBIC LAGRANGE 
+#define INTERPOLATE QUADRATIC // LINEAR QUADRATIC COSINE CUBIC LAGRANGE 
 #define CHORUS_WAVEFORM WAVEFORM_TRIANGLE // WAVEFORM_SINE WAVEFORM_SAWTOOTH WAVEFORM_SAWTOOTH_REVERSE WAVEFORM_SQUARE WAVEFORM_TRIANGLE
 #define CHORUS_DELAY_LENGTH (16*AUDIO_BLOCK_SAMPLES)
 
diff --git a/effect_modulated_chorus.cpp b/effect_modulated_chorus.cpp
index 8059488..1a2c03b 100644
--- a/effect_modulated_chorus.cpp
+++ b/effect_modulated_chorus.cpp
@@ -58,7 +58,7 @@ boolean AudioEffectModulatedDelay::begin(short *delayline, int d_length)
   _delay_length = d_length;
   _delay_length_half = d_length / 2;
 
-  memset(_delayline, 0, sizeof(short)*_delay_length);
+  memset(_delayline, 0, sizeof(int16_t)*_delay_length);
 
   return (true);
 }
@@ -69,8 +69,8 @@ void AudioEffectModulatedDelay::update(void)
   audio_block_t *block;
   audio_block_t *modulation;
 
-  short *bp;
-  short *mp;
+  int16_t *bp;
+  int16_t *mp;
   float mod_idx;
 
   if (_delayline == NULL)
@@ -83,24 +83,24 @@ void AudioEffectModulatedDelay::update(void)
   block = receiveWritable(0);
   modulation = receiveReadOnly(1);
 
-  if (block && modulation)
-  {
 #ifdef INTERPOLATE
-    int8_t j;
-    float x[INTERPOLATION_WINDOW_SIZE];
-    float y[INTERPOLATION_WINDOW_SIZE];
-    modulation_interpolate.valuelenXY(INTERPOLATION_WINDOW_SIZE);
-    modulation_interpolate.valueX(x);
-    modulation_interpolate.valueY(y);
-
-    for (j = 0; j < INTERPOLATION_WINDOW_SIZE; j++)
-      x[j] = j;
+  int8_t j;
+  float x[INTERPOLATION_WINDOW_SIZE];
+  float y[INTERPOLATION_WINDOW_SIZE];
+  modulation_interpolate.valuelenXY(INTERPOLATION_WINDOW_SIZE);
+  modulation_interpolate.valueX(x);
+  modulation_interpolate.valueY(y);
+
+  for (j = 0; j < INTERPOLATION_WINDOW_SIZE; j++)
+    x[j] = float(j);
 #endif
 
-    bp = block->data;
-    mp = modulation->data;
+  bp = block->data;
+  mp = modulation->data;
 
-    for (int i = 0; i < AUDIO_BLOCK_SAMPLES; i++)
+  if (block && modulation)
+  {
+    for (uint16_t i = 0; i < AUDIO_BLOCK_SAMPLES; i++)
     {
       // write data into circular buffer
       if (_circ_idx >= _delay_length)
@@ -117,15 +117,17 @@ void AudioEffectModulatedDelay::update(void)
 #ifdef INTERPOLATE
       // get x/y values around mod_idx
       uint16_t i_mod_idx = int(mod_idx + 0.5);
+      uint8_t c = 0;
       for (j = INTERPOLATION_WINDOW_SIZE / -2; j <= INTERPOLATION_WINDOW_SIZE / 2; j++)
       {
         int16_t ji_mod_idx = i_mod_idx + j;
         if (ji_mod_idx > _delay_length)
-          y[j] = _delayline[ji_mod_idx - _delay_length - 1];
+          y[c] = float(_delayline[ji_mod_idx - _delay_length - 1]);
         else if (ji_mod_idx < 0)
-          y[j] = _delayline[_delay_length + j + 1];
+          y[c] = float(_delayline[_delay_length + j + 1]);
         else
-          y[j] = _delayline[ji_mod_idx];
+          y[c] = float(_delayline[ji_mod_idx]);
+        c++; // ;-)
       }
 
       modulation_interpolate.valueI(mod_idx);
@@ -155,8 +157,12 @@ void AudioEffectModulatedDelay::update(void)
     }
   }
 
-  // transmit the block
-  transmit(block, 0);
-  release(block);
-  release(modulation);
+  if (block)
+  {
+    transmit(block, 0);
+    release(block);
+  }
+
+  if (modulation)
+    release(modulation);
 }
diff --git a/effect_modulated_chorus.h b/effect_modulated_chorus.h
index 6c26759..445d9fd 100644
--- a/effect_modulated_chorus.h
+++ b/effect_modulated_chorus.h
@@ -50,10 +50,10 @@ class AudioEffectModulatedDelay :
   private:
     audio_block_t *inputQueueArray[2];
 
-    short *_delayline;
-    short _circ_idx;
-    int _delay_length;
-    int _delay_length_half;
+    int16_t *_delayline;
+    int16_t _circ_idx;
+    uint16_t _delay_length;
+    uint16_t _delay_length_half;
 };
 
 #endif