diff --git a/public/wasm/synth.wasm b/public/wasm/synth.wasm
index d71e994..1d8a423 100644
Binary files a/public/wasm/synth.wasm and b/public/wasm/synth.wasm differ
diff --git a/wasm-src/src/chip/ym2608.cpp b/wasm-src/src/chip/ym2608.cpp
index d6e93af..7acc99f 100644
--- a/wasm-src/src/chip/ym2608.cpp
+++ b/wasm-src/src/chip/ym2608.cpp
@@ -32,7 +32,7 @@ class Ym2608InstrumentView {
       : instrument_(instrument) {}
 
   std::uint8_t value_fb_al() const noexcept {
-    return (instrument_.fb & 0x7) >> 3 | (instrument_.al & 0x7);
+    return (instrument_.fb & 0x7) << 3 | (instrument_.al & 0x7);
   }
 
   std::uint8_t value_lfo_freq() const noexcept {