Bryce, I was reading an old post of yours about Ampex consoles. I picked up a Signature with the El34/6L6 mono's I' also got 2 copies of the manual with one signed. I purchased it from the grandson of the original owner, who also was a dealer of them. I'm in process of rebuilding them with the help of Mike Samra. Do you have big copies of the schematics of the 403 preamp? Thanks Roger. Rab53