First off, this Reverb Amp is probably one of the the most unnecessary pieces of equipment you can have in your stereo system. Having said that, It's way cool and if your a collector like me, than how can you pass up something so rare. ? I had in the past, a complete Pioneer Spec system with all the vintage Pioneer equipment I could find. I had never seen one of these before I bought this one. They are around, but not many. and not near this cond, if working at all. This one works and it is nice and ads that little something to your system. If not just reverb and expansion. Thank you and good luck.