Build Thread: Standalone Preamp-Harmonic Vibrato-Reverb Thingawhutzit

[alathIN]

This has been a long gestating project - with lots of help here and elsewhere.

I'm really happy with the Trinity TC15 amp I built, but it just lacks a couple of things: 1) maxed out high gain tones, 2) reverb, 3) tremolo/vibrato.
So this has the classic Fender spring reverb, with a couple of well known mods (like dwell and a bright cap), one less well known (tone control) and one new (extra triode in reverb recovery).
I got fascinated with the Fender Harmonic Tremolo and just had to build one.
And finally, just 'cause kitchen sink, a preamp that borrows heavily from the high gain Marshalls, along with the switchable cathode resistor mod.

The idea is that it will take an instrument input (into the preamp), or take an effects loop send signal from my amp - and feed back into my amp's power stage.

The power stage is probably more elaborate than needed. I wanted to be sure I was feeding all these circuits the B+ they were designed around and sound good with, especially the Harmonic vibe/trem circuit which I've heard is very tweaky. Also I am trying a ground lift circuit (from Merlin's site) to avoid ground loop problems with my amp.

Schematic


Layout


I've got a brother and a dad who are engineers, helping me along with SolidWorks. It has been a steep learning curve but well worth it - a lot of stuff would not have fit if I hadn't been able to try it out virtually first. Here's a rendering of the chassis, doghouse, transformers, and tubes.


Today I made drawings from SolidWorks and printed them out.

Stuck the chassis drawing on a sheet of .063 5150
Hey I am just realizing 5150 is an aluminum alloy, as well as an EVH amp (or EVH's favorite number?)


And also printed drill guides for the main turret board and the doghouse board (so hopefully the holes will line up with the chassis!)


For those who haven't tried it, I'm super pleased with the Hoffman turret board service. Very nice stuff, and cost effective - getting your own custom board made and competitively priced vs. a premade board.
Plus I like the look of the black carbon-epoxy stuff.
I will find out tomorrow what it is like to drill.