I don't know the answer to that. However, I had one of these back in the day that I ultimately ran in the line level effects loop of a very early Mesa Boogie Mark II combo. I've never been a big fan of any Flanger effects, but the Doubler effect in this device was to die for, and I overused it like crazy on lead solos from approximately 1979 to 1983. Back then I didn't know anything about differences in impedance, or line level versus instrument level signals, etc. When I first bought it, I patched it between my guitar and the instrument input of the Boogie. The hiss and noise it produced was unbearable. Effects loops in guitar amps were a brand new thing to me in 1979, and I warily decided to patch it in there thinking I was going to blow something up. Ha Ha... It was dead quiet in that Boogie loop, and it sounded amazing. If someone decides to clone it as a pedal, they're going to have to be sure that it can run quietly at instrument signal level.