A very useful box of tricks featuring a multimode filter, LFO, spring reverb and powerful distortion. I use this mainly with the Roland TB-303 ; the LFO is great for adding some subtle movement to an acid line, in a similar way to the inbuilt LFO on an SH-101. The filter sounds lovely, but be careful with that resonance control - it will blow speakers if you're not careful. I'd advise sticking a limiter or compressor after this in the effects chain. The distortion is great on drum machines, especially nice on 808 bass and snares I find.