More debugging... ;) After requesting a CC dump with the SysEx message F0 00 00 7E 46 <device-number> 0E F7 (with <device-number> = 0) also a wrong CC parameter value is returned from the SID ( except values divisible by 8 ) Some examples: volume set in the SID menu: 0 returned CC value after requesting CC dump via SysEx: 0 volume set to 0, returned 0 volume set to 8, returned 8 volume set to 19, returned 16 ( 0x10 ) volume set to 32, returned 32 ( 0x20 ) volume set to 91, returned 88 ( 0x58 ) volume set to 120, returned 120 ( 0x78 ) volume set to 127, returned 120 ( 0x78 )