It's a quad VCA ? like most Doepfer stuff, clean and generic. My one blew a chip after 2 days, I was too lazy to send it back even though it was under warranty and replaced the hot chip myself (actually, I replaced all 4 because I didn't trust the ones that were in there). It's been working fine ever since, but I'm knocking off a couple of stars here because Doepfer Q.C. didn't burn in the unit properly.