The Amp Garage

If you move the PT and OT apart, the result will still sound similar, but there will be a difference to my ear. I've wondered why the PT and OT are so closely positioned in Wreck builds. Can you describe the difference you hear? Probably because the chassis was what was available to Ken and it is s...

Lots of original Trainwreck Expresses and Liverpools were stable at full volume. I had several. However I would never run them like that because they were too dense and "muddied". And most did not have the grid stoppers.. Your amps were stable full volume including TMB and presence set to 10/max? I...

I'm curious too.. It would be extremely hard and annoying to swap transformers in a Wreck. Reject aka undocumented express has a circular hole on the power supply board cut out to access the 1 bolt that is other wise hidden. Wonder what the story is on this. Did the output need replaced and was the ...

Great Sounding Amp, Great Sounding guitars, Great sounding guitar player... almost perfect except you get to hear a little bit of hum when he is telling the story of everything. That little touch of hum gives me the feeling the recording is authentic and not a studio creation. Has me thinking I'll ...

I think I read that you are supposed to be able to dime every knob to 10 turn away from the amp, play and a real Trainwreck is stable.

I'm pretty sure Glen said he had to change his 47p PI snubber to 100p to keep the amp stable but I don't remember if that was the amp dimed.

Sounds like you are running your tubes around 55%, fairly cool. Your B+ would drop with hotter bias - Jeff's is about 70% of plate dissipation. Yep, I think this usually sounds best with most amps but I wouldn't describe it as a cool bias. Depending on wall voltage and bias I wouldn't be surprised ...

jeffkt wrote: ↑Thu Jan 13, 2022 5:28 pm My original express was 400 v dc b+
With the new pacific power I am only getting 385 v dc B+
Bias set at 46 ma

What's your wall voltage?

I have 2 Expresses built with Rocking Class Original spec Transformers and I get 400 ish biased arround 34ma. Wall is 121 122v

Rocking Class posted all the files of Kens transformers they could find, 18 or so on here. Sad I lost all of them. They were all very similar, maybe different lead length difference on a lot of them? Non were 7k5.

Pretty sure it was debunked as 6k6. Pacific released 20 or so of kens transformer documents and non had 6k6 if I remember correctly.
Also the early amps with the Gray Stanor apear to be the a 3801 as seen in the express.

This was my Liverpool "Chante".. Sold to Gene at Ultrasound. She had NOS Euro tubes, but I think they were changed by the new buyer. I had Valvo's in the amp. But the Liverpools sound great with lots of different European tubes.. I never did prefer Mullards tho.. Bugle Boys, Valvo's and some Telefu...

I have 10 NOS Mullard Xf2 El34s. I can get 3 pairs to be matched within 4 ma in my Express clone at around 400vdc and the slight mismatch at 3 or 4ma sound best. The other 2 pairs are off by 6 and 8 Ma and don't sound as good IMO. Ideally having two bias pots would rectify this but I'm not moding my...

Thanks for all the suggestions fellas. Looks like 6v6 makes the most sense.

I have a power transformer that is rated at 100Ma + 350v secondary's that makes about 450 dc with a Gz34. I used it in a JTM 45 and it sounded good but sagged to much for authentic JTM45 tones. Any idea what power tube would be suited for this? Looking to build a 3 12ax7 preamp. Would a 12bh7 be sui...

I don't recall seeing a liverpool/express with out a bright switch on the front panel.

I may have read JM wasn't using bright switches to help keep the amps stable.

I always use my fingers but I likely will try the keyhole washer that comes with the switch on next builds.
Probably just a small drill hole will do.