My first custom amp build has begun.

Matthews Guitars

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After considering my many options and taking into account my skill level and past history of rebuilding a number of Fender and Marshall amps over the last two years, I've begun acquiring parts and will be buildling a Trainwreck Express. The build is planned for two 6V6 power tubes but I'm thinking of dual wiring it for EL84s as well. If I do that, then EITHER a pair of 6V6s will be installed lin their sockets, OR a pair of EL84s will be installed in their sockets, but never both pairs installed at once. Or I could install circuit switching to choose between one pair and the other.

I've already built the pair of turrent boards, just for practice and experience. They came out good enough that I will probably use them. I've ordered the transformers. I've asked my local sheet metal shop, which does my Marshall replacement front and rear panel work, to quote me on the chassis by the print.

With the transformers on order, that's a commitment. This will be built.

What attracts me to the Trainwreck is its huge controllability using only the guitar volume control. Crank the amp, and it's not very loud to start with, and from there on it's all controlled with guitar volume and pick attack. This gives a range from squeaky clean to metal level overdrive with no need to channel switch or touch the amp.

It's also a simple circuit and easy to build.

I'm considering including a built-in power attenuator because why not? There's room in the chassis for that.
 

william vogel

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Just be careful with putting 10lbs of stuff in a 5lbs bag. A Trainwreck is on the edge of stability and I’d recommend sticking to the fundamental amp on the first go around. I’d hate for you to build a dead duck without first enjoying the complexity of the original. 6v6 is okay but EL34’s are where it’s at with an Express. The little tubes don’t load the transformers meant for the big glass. The power transformer is over spec for EL34’s and with 6v6 it really needs about 10k impedance on the output transformer to squish the waveform. El84 need less than 320 volts, the taps are on the power transformer. The tail resistor on the phase inverter needs to swap from 10k to 47k with the El84 along with tweaks to the bias supply. About -30 volts for EL34’s or 6v6 and -10.5 volts for EL84.
 

Red Solo Cup

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Cool project. Past couple of years that I have been lurking around here, I thought you hae already done this kind of thing times "X". Looking forward to your end results posts.
 

Matthews Guitars

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I've rebuilt amps but never built one that never existed before. I've got a lot of reading and planning to do before I actually start putting parts in a chassis.

I'm on another forum (amp garage) that has a subforum dedicated to Trainwreck builds. I'm learning from it.

There are several power attenuator options that are "standard options" for Trainwreck types. I won't be entering new terroritory if I choose to install one.
 

Guitar-Rocker

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If you desire an amp with "dual power tubes", but only one at a time, look into the Dockery amp idea. That schematic uses an "either / or" BUT NEVER BOTH choice of EL84 and 6V6 tubes. I built one for a guy in Boston, and the concept works well.

When I said look at the Dockery, I meant to look at how the power section is structured, not the overall idea of amp
 
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