Well, it took a while, but I finally have most of my 6 Ampex 351 pre-amps built. They sound great, I’m really pleased. Following the mods and circuit edits developed by Electrical Audio, we made new circuit boards (thanks to Ian Anderson for his PCB help) and, having gutted the old units of all but the transformers and BIG meters, created our own version of this classic tube pre.
Using real high end components from manufacturers like Mojotone, Vishay and Hairball Audio, the result is a classic sound with low noise floor and a wide range of tone from clean to “OH MY GOD”. I’ve used the prototype with ribbons and condensers (we added an onboard soft start phantom supply) and just love it.
All the documentation from Electric is available in the Schematic Vault http://dev.danrudin.com/Schematic_vault/index.php?dir=Ampex/ and I’ll try to post my own mods and tweaks when I have a minute.
