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Preamp suggestions for modular amp design

Posted: Mon Feb 19, 2018 6:18 pm
by KingNed
I'm in the process of building a bit of a modular amp design-type-thing. I have a stereo QSC poweramp; and in the 1U space above it in the rack case, I'm going to have 2 preamps in half rack enclosures that I plan to chop and change depending on what sound I'm going for. My initial design is one side being a Sunn Model T preamp, and the other side being a Fender style preamp. I'm keeping it all solid state.

I have all the stuff to build the Model T preamp ready, and I have someone more skilled than me working on a schem/pcb for a Fender preamp. However, the latter isn't going to be ready very soon, and I'm recording in early April. I need to get one other preamp finished ASAP, and I'm drawing a blank on what to build. I'm looking for a PCB that's readily available. I've tried many a tagboard build, but I'd rather not use one (mainly as I can rarely get them to work). I don't have time either to design and prototype a PCB design, although feel free to suggest ones for future builds.

I was considering one of the amp emulations from ROG, but couldn't find any information about how they would behave going into a poweramp. Another one I was looking at was the OLC Orange Peel but, again, not much information on how it works straight into power amps. Has anyone built a preamp/amp emu/amp-in-a-box that they've used going either into an effects loop or power amp which they can recommend building? I just want something clean/crunchy which I'll drive with fuzz pedals.

Re: Preamp suggestions for modular amp design

Posted: Mon Feb 19, 2018 7:17 pm
by BetterOffShred
The model T is a fender style preamp..

I think someone makes a JCM800 preamp pcb.. maybe that will get you where you're going.

Re: Preamp suggestions for modular amp design

Posted: Mon Feb 19, 2018 7:40 pm
by KingNed
BetterOffShred wrote:The model T is a fender style preamp..

I think someone makes a JCM800 preamp pcb.. maybe that will get you where you're going.
Is it? Hah, shows my amp knowledge...

I'll have a look but I couldn't find anything when I did a search originally.

Re: Preamp suggestions for modular amp design

Posted: Mon Feb 19, 2018 10:49 pm
by BetterOffShred
Most amps from back in the day are a FMV or Fender Marshal Vox tonestack with some variance on cathode cap size in the gain stages and a few tweaks in the classic phase inverter. Sunn strapped theirs onto some bigass iron and enormous tubes, and a doom monster was born. Really if the fender Bassman had bigger iron and another set of octals it would sound pretty much the same, peep some Bassman doom videos.

All the good builds I want to recommend are stripboard.. I believe Wampler makes an SLO-100 preamp in a box, a couple of dudes over on tagboard did a pretty legit Model T pre, jcm800 pre, 59 Bassman pre, etc. They all sound amazing. PCB is another story. I'll do some looking