The SY22 has 61 (five octaves) unweighted velocity sensitive keys with aftertouch. It can play back up to 32 voices or 16 notes. Each sound programme uses two or four voices. There are two different programme configurations, being either one AWM (Yamaha's
PCM technology) and one FM element (voice) or two AWM and two FM elements. There are sixty four factory pre set sound programmes and sixteen pre set multimode programmes in ROM. The same amount of storage space can be used for user programmes. The user memory can be doubled with an optional battery buffered RAM card (MCD32). The AWM part does not have filters or other wave shaping functionality. The FM part is two operators, but since it does not contain only sine waves, but 224 waves, partly sampled from Yamaha's DX7 synthesiser, the FM synthesis is more complex than any other two op FM synthesis at the time. The Multi mode combines up to eight sound programmes which can be played at once. ==Vector synthesis==