Anyone with an Audio Centron RMA 2000 schematic?

I'll look in the warehouse for that one in my old files, but until I can get to that, contact Loud Technologies and ask their support if they have that one. They bought the Crate brands from SLM some time ago and may have it in their archives. AC was the pro audio brand from Crate. In fact, the Audio Centron stuff may have been refiled as Crate Pro Audio, so if they have no ACTMA2000, ask them if they have that model number in Crate.

And as another resource, teemu seems to have a bunch of Crate documents. Visit Solid State Guitar Amp Forum | DIY Guitar Amplifiers - Index and post a request there.