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Hoffman Amps Forum image Author Topic: Trainwreck Express EL34 clone  (Read 2435 times)

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Offline Kaptinkangaru

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Trainwreck Express EL34 clone
« on: September 26, 2026, 09:31:20 pm »
Here's one i did earlier this year- a Trainwreck Express clone, making about 45 watts from two EL34's. Pacific Audio Trainwreck transformer set.  Sylvania 5751 V1, Sonotone 12AX7 V2, JJ 12AX7 V3, Mullard reissue EL34's. DC heaters for the preamp from a Recom brick, AC to the power tube filaments. Used a 17x6x3 chassis because i didn't love how most builds, including originals, had the transformers practically on top of each other. Circuit laid out in EasyEDA, milled on desktop CNC, faceplate laser engraved then milled. Still need to build a headshell one of these days, picked up a nice etimoe slab a few months ago, havent had the time yet.

some clean playing:
https://photos.app.goo.gl/TqX9VBCUAhpyS2bX8

and with the volume cranked(into an attentuator of course):
https://photos.app.goo.gl/MgKsUjywW7qDBxGG8
« Last Edit: September 27, 2026, 09:00:20 am by Kaptinkangaru »

Offline Kaptinkangaru

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Re: Trainwreck Express EL34 clone
« Reply #1 on: September 26, 2026, 09:32:41 pm »
couple more shots of the board front and back, and the faceplate under the laser.
« Last Edit: September 27, 2026, 08:46:41 am by Kaptinkangaru »

Offline dickjonesify

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Re: Trainwreck Express EL34 clone
« Reply #2 on: September 27, 2026, 08:58:54 am »
Excellent build! Sounds and looks great.

Offline pdf64

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Re: Trainwreck Express EL34 clone
« Reply #3 on: September 27, 2026, 05:49:34 pm »
It looks great, but with the lead dress of the OT primary wiring (and its proximity to the input / early stage circuitry), I'm surprised it's stable.
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Offline Kaptinkangaru

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Re: Trainwreck Express EL34 clone
« Reply #4 on: September 27, 2026, 06:39:45 pm »
It looks great, but with the lead dress of the OT primary wiring (and its proximity to the input / early stage circuitry), I'm surprised it's stable.

It was definitely a concern of mine, as the OT wires needed extending regardless. I tested with longer leads away from the board, zero difference in noise/interference. From the sound of it, it seems pretty happy to me.

Offline Democles

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Re: Trainwreck Express EL34 clone
« Reply #5 on: September 28, 2026, 12:42:43 pm »
Always good to see that a Trainwreck Express is born.
Nice work! Looks amazing!

These are the two I built
Trainwreck Express Cesspool style.

With a Fender Basseman tone control.

 PostPI Master and  half power reduce switch.
 Dumbleater-based Tube FX
« Last Edit: September 28, 2026, 01:13:27 pm by Democles »

Offline Democles

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Re: Trainwreck Express EL34 clone
« Reply #6 on: September 28, 2026, 12:44:19 pm »
more pics.

Offline Democles

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Re: Trainwreck Express EL34 clone
« Reply #7 on: September 28, 2026, 12:51:30 pm »
Last one.
I forgot the bias print,now attached :icon_biggrin:
complete build : https://zelfbouwaudio.nl/forum/viewtopic.php?t=32462
« Last Edit: September 28, 2026, 02:51:56 pm by Democles »

Offline Kaptinkangaru

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Re: Trainwreck Express EL34 clone
« Reply #8 on: September 28, 2026, 08:30:26 pm »
Last one.
I forgot the bias print,now attached :icon_biggrin:
complete build : https://zelfbouwaudio.nl/forum/viewtopic.php?t=32462

Looks great, hoping to find the time this winter for some woodwork, nice inspiration

Offline tubeswell

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Re: Trainwreck Express EL34 clone
« Reply #9 on: September 29, 2026, 09:01:16 pm »
Love the artwork


Got me thinking



« Last Edit: September 29, 2026, 09:03:34 pm by tubeswell »
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Offline kagliostro

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Re: Trainwreck Express EL34 clone
« Reply #10 on: September 30, 2026, 03:45:20 am »
Nice job, very cool faceplate top

Franco
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Offline DummyLoad

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Re: Trainwreck Express EL34 clone
« Reply #11 on: September 30, 2026, 10:39:02 am »
couple more shots of the board front and back, and the faceplate under the laser.

Nice work for a single sided PCB.

Are those Xicon or Panasonic ECQ coupling caps?


--Pete

Offline Kaptinkangaru

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Re: Trainwreck Express EL34 clone
« Reply #12 on: September 30, 2026, 02:53:25 pm »
couple more shots of the board front and back, and the faceplate under the laser.

Nice work for a single sided PCB.

Are those Xicon or Panasonic ECQ coupling caps?


--Pete

Its been a few months, but from what I can see and recall, I used Nichicon snap ins and radials in the power section, as well as a couple Panasonic Elcos in the audio path. Film caps are likely a mix of some Panasonic, Cornell Dubliner, and Kemet, whatever i had on hand in the chosen value. I'm a big believer in tech specs, not snake oil.....
« Last Edit: September 30, 2026, 03:09:05 pm by Kaptinkangaru »

 


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