I like the Boss ME-50 very much. And as weird as it may sound, there is also the bass version (ME-50B) that could fit... I encourage you to try it on!
-Roland JX3P+PG200, D50+PG1000, Juno 106, MKS50/70, JP8080, U220, MVS1, MDC1, MSE1, MOC1, TR707
-Korg M1R/M3R, MicroKorg, Micro X, Kaossilator, Monotron X3
-Yamaha DX7, TX816, TX81Z, Motif Rack
-Future Retro 777, DSI Mopho, EMU Proteus FX