diff --git a/game-ctrl/buttons.c b/game-ctrl/buttons.c
index fbbdb08..b52a99d 100644
--- a/game-ctrl/buttons.c
+++ b/game-ctrl/buttons.c
@@ -84,27 +84,22 @@ void buttonsExec(void *handle) {
 
   if (buttonsMoveLeftPressed()) {
     stoneMoveLeft();
-    soundCtrl(SOUND_MOTION);
     buttonPressed = 1;
   }
   if (buttonsMoveRightPressed()) {
     stoneMoveRight();
-    soundCtrl(SOUND_MOTION);
     buttonPressed = 1;
   }
   if (buttonsRotateLeftPressed()) {
     stoneRotateLeft();
-    soundCtrl(SOUND_MOTION);
     buttonPressed = 1;
   }
   if (buttonsRotateRightPressed()) {
     stoneRotateRight();
-    soundCtrl(SOUND_MOTION);
     buttonPressed = 1;
   }
   if (buttonsMoveDownPressed()) {
     stoneMoveDown();
-    soundCtrl(SOUND_MOTION);
     buttonPressed = 1;
   }
 
diff --git a/game-ctrl/config.c b/game-ctrl/config.c
index 37bd0dd..a5e69b2 100644
--- a/game-ctrl/config.c
+++ b/game-ctrl/config.c
@@ -7,9 +7,11 @@
 #include "eeprom.h"
 #include "display.h"
 #include "shapes.h"
+#include "sound.h"
 
 
 static bool configChanged = false;
+static bool muted = false;
 
 static void configHandleFlash() {
   uint8_t color = eepromReadFlashColor();
@@ -50,7 +52,26 @@ static void configHandleBrightness() {
   }
 }
 
-void (*configHandler[])(void) = { configHandleFlash, configHandleResetHighScore, configHandleBrightness };
+static void configHandleAmplitude() {
+  displaySetValue(eepromReadAmplitude());
+  if (muted) {
+    muted = false;
+    soundCtrl(SOUND_START);
+    soundCtrl(SOUND_UNMUTE);
+  }
+
+  if (buttonsConfig2Pressed()) {
+    configChanged = true;
+    uint8_t amplitude = eepromReadAmplitude() + 1;
+    if (amplitude > 15) {
+      amplitude = 0;
+    }
+    eepromSetAmplitude(amplitude);
+    soundCtrl(SOUND_COMMAND + SOUND_SUBCMD_AMPLITUDE + amplitude);
+  }
+}
+
+void (*configHandler[])(void) = { configHandleFlash, configHandleResetHighScore, configHandleBrightness,configHandleAmplitude };
 
 
 void configExec(void *handle) {
@@ -62,7 +83,14 @@ void configExec(void *handle) {
 
     miniCanvasClear();
     canvasClear();
-    miniCanvasSetPixel(configState, 0, _red);
+    if (! muted) {
+      muted = true;
+      soundCtrl(SOUND_MUTE);
+    }
+
+    uint8_t row = configState / 3;
+    uint8_t column = configState % 3;
+    miniCanvasSetPixel(column, row, _red);
   }
 
   if (buttonsConfig1Pressed()) {
diff --git a/game-ctrl/eeprom.c b/game-ctrl/eeprom.c
index d8a42b6..87be004 100644
--- a/game-ctrl/eeprom.c
+++ b/game-ctrl/eeprom.c
@@ -4,7 +4,7 @@
 #include "spi.h"
 
 
-#define MAGIC 0xb001
+#define MAGIC 0xb002
 #define HIGHSCORE_ADDR 0x00
 #define DUMMY 0x00
 #define CMD_READ  0b00000011
@@ -18,6 +18,7 @@ typedef struct {
   uint16_t highScore;
   uint8_t flashColor;
   uint8_t brightness;
+  uint8_t amplitude;
 } t_configBlock;
 
 typedef union {
@@ -93,3 +94,11 @@ void eepromSetBrightness(uint8_t v) {
   buf.v.brightness = v;
 }
 
+uint8_t eepromReadAmplitude() {
+  return buf.v.amplitude;
+}
+
+void eepromSetAmplitude(uint8_t v) {
+  buf.v.amplitude = v;
+}
+
diff --git a/game-ctrl/eeprom.h b/game-ctrl/eeprom.h
index dde1b9e..aa8f8e2 100644
--- a/game-ctrl/eeprom.h
+++ b/game-ctrl/eeprom.h
@@ -5,13 +5,15 @@
 
 
 void eepromInit();
+void eepromCommit();
 uint16_t eepromReadHighScore();
 void eepromSetHighScore(uint16_t v);
 uint8_t eepromReadFlashColor();
 void eepromSetFlashColor(uint8_t v);
 uint8_t eepromReadBrightness();
 void eepromSetBrightness(uint8_t v);
-void eepromCommit();
+uint8_t eepromReadAmplitude();
+void eepromSetAmplitude(uint8_t v);
 
 
 
diff --git a/game-ctrl/game.c b/game-ctrl/game.c
index eeb15ce..583c86a 100644
--- a/game-ctrl/game.c
+++ b/game-ctrl/game.c
@@ -24,13 +24,15 @@ static uint16_t delayFactor(uint16_t level) {
 }
 
 typedef enum { 
+  e_BootWait,
   e_Start, e_NewStone, e_Down, e_DownDelay, 
   e_ClearRowInit, e_ClearRowNext, e_ClearRowCheck, e_ClearRowFlash, e_ClearRowFlashDelay, e_ClearRowWipe,
   e_GameOver, e_GameOverFill, e_GameOverWipe, e_GameOverDelay 
 } state_t;
 
 void gameExec(void *handle) {
-  static state_t state = e_Start;
+  static state_t state = e_BootWait;
+  static uint16_t bootWaitTime = 2500 / GAME_CYCLE_TIME;
   static uint8_t gameOverDelay;
   static uint8_t rowIndex;
   static uint16_t proceedDelay;
@@ -46,6 +48,12 @@ void gameExec(void *handle) {
 #endif
 // --- engine begin -------------------------------------------------------
   switch (state) {
+    case e_BootWait:
+      bootWaitTime -= 1;
+      if (bootWaitTime == 0) {
+        state = e_Start;
+      }
+      break;
 // --- phase: game --------------------------------------------------------
     case e_Start:
       canvasClear();
diff --git a/game-ctrl/main.c b/game-ctrl/main.c
index ccde948..d1ee30a 100644
--- a/game-ctrl/main.c
+++ b/game-ctrl/main.c
@@ -14,6 +14,7 @@
 #include "display.h"
 #include "eeprom.h"
 #include "config.h"
+#include "sound.h"
 
 
 int main() {
@@ -34,6 +35,7 @@ int main() {
     displayInit();
     myRandInit();
     canvasInit();
+    soundInit();
     buttonsInit();
 
     if (isConfigMode()) {
diff --git a/game-ctrl/sound.c b/game-ctrl/sound.c
index 1cde5e0..94da718 100644
--- a/game-ctrl/sound.c
+++ b/game-ctrl/sound.c
@@ -1,10 +1,12 @@
 #include <stdint.h>
 #include "sound.h"
 #include "spi.h"
+#include "eeprom.h"
 
 
 
 void soundInit() {
+  soundCtrl(SOUND_COMMAND + SOUND_SUBCMD_AMPLITUDE + eepromReadAmplitude());
 }
 
 
diff --git a/sound-driver/Makefile b/sound-driver/Makefile
index ecdce2a..35b038d 100644
--- a/sound-driver/Makefile
+++ b/sound-driver/Makefile
@@ -12,7 +12,7 @@ ASFLAGS=$(COMMONFLAGS) -D__ASSEMBLER__
 
 LDFLAGS=-mmcu=$(MCU) -L $(TOOLCHAIN_PREFIX)/include
 
-$(ARTIFACT).elf:	main.o scheduler.o spi.o spi_init.o sequencer.o melody_tetris.o melody_tusch1.o psg.o mute.o melody_pling.o
+$(ARTIFACT).elf:	main.o scheduler.o spi.o spi_init.o sequencer.o melody_tetris.o melody_tusch1.o psg.o mute.o melody_pling.o config.o
 	$(CC) -o $@ $(LDFLAGS) $^
 	$(OBJDUMP) -D $(ARTIFACT).elf > $(ARTIFACT).txt
 
diff --git a/sound-driver/config.c b/sound-driver/config.c
new file mode 100644
index 0000000..3112bd6
--- /dev/null
+++ b/sound-driver/config.c
@@ -0,0 +1,19 @@
+#include <stdint.h>
+#include "config.h"
+
+
+typedef struct {
+  uint8_t amplitude;
+} config_t;
+
+config_t config;
+
+
+void configSetAmplitude(uint8_t v) {
+  config.amplitude = v;
+}
+
+uint8_t configGetAmplitude() {
+  return config.amplitude;
+}
+
diff --git a/sound-driver/config.h b/sound-driver/config.h
new file mode 100644
index 0000000..f3e4b95
--- /dev/null
+++ b/sound-driver/config.h
@@ -0,0 +1,11 @@
+#ifndef _CONFIG_H_
+#define _CONFIG_H_
+
+
+#include <stdint.h>
+
+void configSetAmplitude(uint8_t v);
+uint8_t configGetAmplitude();
+
+
+#endif // _CONFIG_H_
diff --git a/sound-driver/melody_pling.c b/sound-driver/melody_pling.c
index ea02f9b..ebb583e 100644
--- a/sound-driver/melody_pling.c
+++ b/sound-driver/melody_pling.c
@@ -1,8 +1,11 @@
 #include <stdbool.h>
+#include <sys/param.h>
 #include <stddef.h>
 #include "psg.h"
 #include "sequencer.h"
 #include "scheduler.h"
+#include "config.h"
+
 
 const t_tone plingVoice1[] = {
   { .octave = e_O_5,    .note = e_C,     .length = e_L_1_16,    .legato = false, .staccato = false },
@@ -18,13 +21,15 @@ const t_tone plingVoice1[] = {
 };
 
 t_melodies pling = {
-  .melodies = { { .amplitude = 12, .tones = plingVoice1 } },
+  .melodies = { { .tones = plingVoice1 } },
+  .amplitude = 12,
   .numOfMelodies = 1,
   .pace = 200,
   .chip = 1
 };
 
 void playPling() {
+  pling.amplitude = MIN((configGetAmplitude() + 4), 15);
   sequencerPlayMelodies(&pling);
 }
 
diff --git a/sound-driver/melody_tetris.c b/sound-driver/melody_tetris.c
index 75a7e3f..f06bff6 100644
--- a/sound-driver/melody_tetris.c
+++ b/sound-driver/melody_tetris.c
@@ -1,8 +1,10 @@
 #include <stdbool.h>
+#include <sys/param.h>
 #include <stddef.h>
 #include "psg.h"
 #include "sequencer.h"
 #include "scheduler.h"
+#include "config.h"
 
 
 /*
@@ -924,7 +926,8 @@ const t_tone voice3[] = {
 
 #define INITIAL_PACE 160
 t_melodies tetrisTheme = {
-  .melodies = { { .amplitude = 8, .tones = voice1 }, { .amplitude = 8, .tones = voice2 }, { .amplitude = 8, .tones = voice3 } },
+  .melodies = { { .tones = voice1 }, { .tones = voice2 }, { .tones = voice3 } },
+  .amplitude = 8,
   .numOfMelodies = 3,
   .pace = INITIAL_PACE,
   .chip = 0
@@ -932,6 +935,7 @@ t_melodies tetrisTheme = {
 
 void playMelodyTetris() {
   tetrisTheme.pace = INITIAL_PACE; // reset to start value each time
+  tetrisTheme.amplitude = MIN((configGetAmplitude() + 4), 15);
   sequencerPlayMelodies(&tetrisTheme);
 }
 
diff --git a/sound-driver/melody_tetris.h b/sound-driver/melody_tetris.h
index f9d7394..37f6a7e 100644
--- a/sound-driver/melody_tetris.h
+++ b/sound-driver/melody_tetris.h
@@ -5,5 +5,6 @@
 void playMelodyTetris();
 void stopMelodyTetris();
 void playMelodyTetrisFaster();
+void playMelodyTetrisAmplitude(uint8_t a);
 
 #endif // _MELODY_TETRIS_H_
diff --git a/sound-driver/melody_tusch1.c b/sound-driver/melody_tusch1.c
index 043d1a2..320b2e4 100644
--- a/sound-driver/melody_tusch1.c
+++ b/sound-driver/melody_tusch1.c
@@ -1,9 +1,10 @@
 #include <stdbool.h>
+#include <sys/param.h>
 #include <stddef.h>
 #include "psg.h"
 #include "sequencer.h"
 #include "scheduler.h"
-#include "melody_tetris.h"
+#include "config.h"
 
 const t_tone tusch1voice1[] = {
   { .octave = e_O_5,    .note = e_C,     .length = e_L_1_4,     .legato = false, .staccato = true  },
@@ -72,15 +73,16 @@ const t_tone tusch1voice3[] = {
 };
 
 t_melodies tusch1 = {
-  .melodies = { { .amplitude = 12, .tones = tusch1voice1 }, { .amplitude = 12, .tones = tusch1voice2 }, { .amplitude = 12, .tones = tusch1voice3 } },
+  .melodies = { { .tones = tusch1voice1 }, { .tones = tusch1voice2 }, { .tones = tusch1voice3 } },
+  .amplitude = 12,
   .numOfMelodies = 3,
   .pace = 200,
   .chip = 1
 };
 
 void playTusch1() {
+  tusch1.amplitude = MIN((configGetAmplitude() + 4), 15);
   sequencerPlayMelodies(&tusch1);
-//  playMelodyTetrisFaster();
 }
 
 
diff --git a/sound-driver/sequencer.c b/sound-driver/sequencer.c
index 1e4cf14..573ea6f 100644
--- a/sound-driver/sequencer.c
+++ b/sound-driver/sequencer.c
@@ -59,7 +59,7 @@ void sequencerExec(void *handle) {
           if (melody->tones[melody->idx].length == e_L_EndMark) {
             melody->idx = 0;
           }
-          psgPlayTone(melodies->chip, channel, melody->amplitude, melody->tones[melody->idx].octave, melody->tones[melody->idx].note);
+          psgPlayTone(melodies->chip, channel, melodies->amplitude, melody->tones[melody->idx].octave, melody->tones[melody->idx].note);
           melody->lengthCnt = (melody->tones[melody->idx].staccato) ? 
             (calcLength(melodies, melody->tones[melody->idx].length) / 2) : 
             calcLength(melodies, melody->tones[melody->idx].length);
diff --git a/sound-driver/sequencer.h b/sound-driver/sequencer.h
index 7411ae9..c46a3c7 100644
--- a/sound-driver/sequencer.h
+++ b/sound-driver/sequencer.h
@@ -44,7 +44,6 @@ typedef struct {
   uint16_t idx;
   uint16_t lengthCnt;
   t_sequencerState state;
-  uint8_t amplitude;
   const t_tone *tones;
 } t_melody;
 
@@ -53,6 +52,7 @@ typedef struct {
 typedef struct {
   uint8_t slotMask;
   uint8_t chip;
+  uint8_t amplitude;
   uint8_t taskId;
   uint16_t quarterLength;
   uint8_t numOfMelodies;
diff --git a/sound-driver/soundCodes.h b/sound-driver/soundCodes.h
index 72f4824..48ecba4 100644
--- a/sound-driver/soundCodes.h
+++ b/sound-driver/soundCodes.h
@@ -8,7 +8,9 @@
 #define SOUND_GAMEOVER 0x08
 #define SOUND_FANFARE 0x10
 #define SOUND_LOCK 0x20
-#define SOUND_MOTION 0x40
-#define SOUND_PLING 0x80
+#define SOUND_PLING 0x40
+#define SOUND_COMMAND 0x80
+
+#define SOUND_SUBCMD_AMPLITUDE 0x40
 
 #endif // _SOUND_CODES_H_
diff --git a/sound-driver/spi.S b/sound-driver/spi.S
index 6b9288f..ef57f24 100644
--- a/sound-driver/spi.S
+++ b/sound-driver/spi.S
@@ -6,12 +6,21 @@
 receive_isr:
   bit     #UCB0RXIFG, &UC0IFG
   jz      receive_isr_no_data
+  bit     #SOUND_COMMAND, &cmd
+  jnz     receive_isr_no_data
   bis     UCB0RXBUF, &cmd
 receive_isr_no_data:
   reti
 
   .global spiCmdHandler
 spiCmdHandler:
+spiCmdHandler_0:
+  bit     #SOUND_COMMAND, &cmd
+  jz      spiCmdHandler_1
+  ;; insert a call here
+  call    #spiCommandDispatcher
+  mov.b   #0, &cmd
+  ret
 spiCmdHandler_1:
   bit     #SOUND_MUTE, &cmd
   jz      spiCmdHandler_2
@@ -44,11 +53,6 @@ spiCmdHandler_6:
   ;; insert a call here
   bic     #SOUND_LOCK, &cmd
 spiCmdHandler_7:
-  bit     #SOUND_MOTION, &cmd
-  jz      spiCmdHandler_8
-  ;; insert a call here
-  bic     #SOUND_MOTION, &cmd
-spiCmdHandler_8:
   bit     #SOUND_PLING, &cmd
   jz      spiCmdHandler_end
   call    #playPling
diff --git a/sound-driver/spi_init.c b/sound-driver/spi_init.c
index fdef72c..ddcf472 100644
--- a/sound-driver/spi_init.c
+++ b/sound-driver/spi_init.c
@@ -4,9 +4,10 @@
 #include "scheduler.h"
 #include "spi.h"
 #include "soundCodes.h"
+#include "config.h"
 
 
-uint8_t cmd;
+volatile uint8_t cmd;
 
 void spiInit() {
   // SPI slave
@@ -25,7 +26,14 @@ void spiInit() {
   UC0IE |= UCB0RXIE;
 
   cmd = SOUND_IDLE;
-  schAdd(spiCmdHandler, NULL, 0, 100);
+  schAdd(spiCmdHandler, NULL, 0, 5);
 }
 
+void spiCommandDispatcher() {
+  cmd &= ~SOUND_COMMAND;
 
+  if (cmd & SOUND_SUBCMD_AMPLITUDE) {
+    cmd &= ~SOUND_SUBCMD_AMPLITUDE;
+    configSetAmplitude(cmd);
+  }
+}