diff --git a/common/Sound/ym2149/YM2149.vhd b/common/Sound/ym2149/YM2149.vhd
index b5e463cc..ae14e63e 100644
--- a/common/Sound/ym2149/YM2149.vhd
+++ b/common/Sound/ym2149/YM2149.vhd
@@ -62,7 +62,7 @@ library ieee;
 
 entity YM2149 is
   generic (
-	MIXER_VOLTABLE      : std_logic := '0'
+    MIXER_VOLTABLE      : std_logic := '0'
   );
   port (
   -- data bus
@@ -586,11 +586,12 @@ begin
           vol_r <= vol_r + dac_amp;
         when "00" => -- Channel A
           if I_STEREO = '0' then
-            vol_mixer_l <= vol_l + dac_amp;
-          else
-            vol_mixer_l <= vol_l;
+            vol_r <= vol_r + dac_amp;
           end if;
-          vol_mixer_r <= vol_r + dac_amp;
+          vol_l <= vol_l + dac_amp;
+        when "11" =>
+          vol_mixer_l <= vol_l;
+          vol_mixer_r <= vol_r;
         when others => null;
         end case;
       end if;
@@ -667,12 +668,12 @@ begin
       ADDR_B      => vol_table_in_r,
       DATA_B      => vol_table_out_r
       );
-	end generate; -- VOLTABLE
+  end generate; -- VOLTABLE
 
   NO_VOLTABLE: if MIXER_VOLTABLE = '0' generate
     vol_table_out_l <= (others => '0');
     vol_table_out_r <= (others => '0');
-	end generate;
+  end generate;
 
   -- mixed audio output