Does anyone know anything about this pre amp?

Questions:

How does it sound?
How similar is it to the 350 pre amps?
Are replacement parts hard to find?

Thanks

Yeah, I've got several of these that i recapped and put into wooden boxes. all the tubes are pretty standard. They sound pretty cool, i use them mostly for DI boxes, but they're great at creating overloaded kick and snare sounds. I have an Ampex 400, which I believe came just before the 350, and its definitely a better mic pre than the 601's, much bigger sounding and better detail, the 601's have some low frequency distortion i've noticed. useful effects box.