The Roland SC-55-mk II has increased polyphony(28 voices) more patches, raising the total number to 354 instruments and extended, and improved audio-circuitry in the form of 18-bit audio(versus 16-bit in the original SC 55. The selection of effects includes reverb and chorus. The SC-55 featured 317 instrument patches, including the GS drum kits and additional controllers. It came preloaded with the Roland MT-32's variation bank, but lacked the MT-32's re-programmability. To support 24-voice polyphony with 16-part multitimbrality. The SC-55 used both PCM and a cut-down version of the LA synthesis engine. The SC-55 was the first sound module to incorporate the new General MIDI standard. more sound module released in 1991 by Roland. Template HKGLGR2 Roland SC-55 MkII Sound Canvas MIDI SYNTHESIZER Sound Module USED/SC55.EDIROL Description The Roland SC-55(Sound Canvas) is a GS MIDI.