The Amp Garage

Wayne, I originally posted the "simpliest MV ever" file. Have you checked the feedback on that thread? One guy wired his phase inverter exactly per my diagram (which has the signal input to pin 2), even though he used pin 7 as the PI input stage. He was also getting very low volume. Just a suggestio...

Snide, Thanks for the kind comments; your great clip inspired me to send this along. It's funny how many different small ways this circuit can be modified and still retain the great overall tone and dynamics. I used the .002/150k combo and it works well for me,.. but then again I cut the gain of the...

Thanks for the kind words. The speaker was a Rivera, tuned, sealed box with an Electro Voice EV-12L. I really don't know the amp settings but generally I used the amp ~ with the volume @ 1:00, treble @ 9:00, mid @ 10:00; bass @ 3:00; presence @ 12:00. The voltage on the power tube heaters was contin...

Hello all, I just listened to Snide's clip and the general tone reminded me very much of the first Xpress clone I built last year. Attached is a clip my friend David Craton made in his home studio. In this amp I used a variable resistor to reduce the heater voltages on the output tubes for varying t...

Omar, The relay I spec-ed is DPDT. I (and I think most amps that use relays) used the Normally Closed (relay is inactive to engage) switches for the high gain circuits and the Normally Open (relay is energized to engage) switches for the clean; that way when the relay is activated the signal thru th...

Here's a simple circuit I think I got from a Boogie MK 1. I've used it in channel switching applications on Fenders, and it works pretty well. The relay indicated is 5Vdc, 167 Ohm coil, 150mW. If you can't find this specific item, you can probably use something close.

DEH

Thanks Craig, for giving credit where credit is due. I've never read any of Kevin's books, but obviously he "found" this before I did.
Anyway, maybe the exposure here will give a few more amp builders a new tool.

David Hicks

I came up with this MV design when building my first TW clone (I wanted to tame the volume a little for home use). I won't swear it's original, but I've never seen it anywhere. The sound is pretty much flat,..nothing missing, just a little high end boost starting about 3KhZ.

David Hicks

Mike, Which schematic of the Express did you use? I've built a couple from my own drawings of Kelly '90, but the TW schematics I've seen on the web are all pretty close. I can't imagine if you've stuck close to these that you don't have enough gain. I've substituted a 12AU7 for V1 and a 12AT7 for V2...

If you're new to TWrecks you may not know yet, but there is no one schematic for these. Ken Fischer apparently built these one at a time and changed them as time passed. I would guess that most of the variations on the web are based on iterations of actual designs. I have a schematic of a TW (Kelly ...

I agree with part of what Doug said in that these amps are "special" and it may be that there is an "on the edge" factor that might be impractical for most manufacturers to copy without fear of warranty problems. Certainly I've seen numerous Boogies that exhibited very bad sounds if used in certain ...

I haven't been a member long and I don't know how to upload a message or if this is copacetic with the webmaster. I'll be glad to deliver the files directly in a zip to anyone who requests it. I can be emailed directly on this as well: ampdoc@juno.com

Thanks for the interesting link. I won't pretend that I know as much about solder techniques and "aircraft quality" construction as Andy, but years of experience repairing and building guitar amps, and common sense, led me to the same conclusions: layout is critical, (although again, I believe commo...

I'd like to propose a heretical view here. I agree that layout is one of the most important aspects of building and so, when I decided to build a couple of Express clones I went with a printed circuit board. I know, I know,...PCB are crap,... they don't sound good,... the voltages are too high,... y...