The Sauce Preamp; new diy build

[jarrodthebobo]

A little while back I had posted a video here concerning a Trainwreck Express preamp I had built for shits and giggles; make recording real easy and sound real niceeeeee. I got bored of it though, as one does when they like to tinker too much . So, I decided to really just muck around with a basic 2 12ax7 circuit design and combine a bunch of weird garbage from tons of other amp designs until I found something kind of different, and kind of cool. I'll let you guys give it a listen;

https://soundcloud.com/jarrod-beauchemi ... -tone-test

The preamp is going directly into my m-audio 4x4 and running into some cool ass cab impulses from OwnHammer; specifically the GNR set. Got some plate reverb going on via the Tal 4 reverb vst, and some delay from the built in mixcraft classic delay. Honestly wasn't aiming for straight VH tone with this thing, but somehow it happened.

Goes to show you, maybe the magic is 100% in the Marshalls... who knows

Once I get this thing finalized and cut down on some of the noise and rats-nest wiring, i'll post some videos and pics of the thing, along with a circuit so anyone who wants to try and give this thing a go can.

[studiodunn]

Sounds like a great VH tone going on right there. Love it!

[jarrodthebobo]

Sounds like a great VH tone going on right there. Love it!

Thanks man!!

Might as well post the basics of the circuit that I remeber off hand;

Start with a basic express style circuit; thats the easiest way I can describe it.

The tone cap is 250pf. Stage 1 has a 1000pf bypassing the plate. Cathode biased to 2.2k with .68uf cap. Gain knob has a 1000pf bypass cap.
Second stage has a 1.5k cathode with a 10uf cap. Then, going into the 3rd stage we have a 68k grid blocker, and a pot to ground (500k pot) which is used as a secondary gain control to the 3rd stage. The big change here is the cathode bias of stage 3; which is 820ohms.
From the 3rd stage we go through a 33k gridstopper into a "fake" pi, which is just an additional gainstage biased to 2.2k, no cap bypass. Plate is 100k. Output to another 1m pot as a mastwr volume; bypassed with 100pf for low volume treble.

All cc are the same as an express. Filtering is different though and I'll have to check when I get the chance.

This can be a mess of oscillation if you're not carefull; so mind your wire placement !