Rate the Express output transformers.

[gktamps]

Probably this:
https://ampgarage.com/forum/viewtopic.php?t=23872

I think that effort is either defunct or has been incorporated into Pacific's marketing efforts, which have been problematic, as another recent discussion has indicated:
https://ampgarage.com/forum/viewtopic.php?f=6&t=35007

My speculation is PacTrans isn't interested in supplying RJ because they think they can go it alone.

[Littlewyan]

Ah yes that was it.

Just looking at other transformers on the Pacific site, it seems the spec is pretty much wrong on a few of them. Odd impedances or current and voltage ratings. Very odd.

[WhopperPlate]

I am having a hard time talking to any transformer manufacturer…heyboer said they weren’t gonna have anything available til January back in November …

[WhopperPlate]

RJ

I reached out to pacific concerning the 6.6k and they sent this:

The 6.6kOhm is not the authentic impedance for the 30W trainwreck output transformer.
I tested the impedance ratio for PAM-OT-30-54R and we get an average 7.5kOhm. See attached.
The PAM-OT-30-54R and PAM-PT-30-54R are the transformers Ken Fischer used.

[Colossal]

RJ

I reached out to pacific concerning the 6.6k and they sent this:

The 6.6kOhm is not the authentic impedance for the 30W trainwreck output transformer.
I tested the impedance ratio for PAM-OT-30-54R and we get an average 7.5kOhm. See attached.
The PAM-OT-30-54R and PAM-PT-30-54R are the transformers Ken Fischer used.

The original output transformer was a Stancor 3801. When Stancor dried up, Ken switched to Pacific. Does it make sense that Ken would change from to 7k5 from 6k6? Does the math and load line analysis support that change? The Pacific OTs are certainly more aggressive sounding that the Stancors. We have also seen several instances in the past where Pacific contradicts the (extensive) Trainwreck research here. There was also past drama where the son of the owner (I think) showed up with their new "Rocking Class" line of transformers, threw some weight around, and then fizzled out and disappeared. More recently, if you look at their so-called vintage clone offerings, the primary impedances don't match the known vintage specs from which the clones were copied. So, I am quite disinclined to put stock in Pacific as being a credible source on Trainwreck matters, despite their being the vendor for Ken for a while.

[WhopperPlate]

The apparent discrepancies begged for me to share. Just trying to provide material for insight

[Colossal]

The apparent discrepancies begged for me to share. Just trying to provide material for insight

Sorry, I wasn't trying to shoot the messenger!

[RJ Guitars]

It's all interesting, I can't say we'll ever know for sure but if our forefathers at AmpGarage did their due diligence I be inclined to believe them over the newer info from Pacific... my 2 cents.

The real guru of Wreck trannies is Rob Hinson and he knows more than anybody else as far as I can tell. He studied these things thoroughly and my understanding is that all the transformers that were established as the Wreck standards were based on actual transformers that were cloned, reverse engineered, or otherwise studied from genuine Wrecks. Rob has taken credit for establishing these specs and he's always been been pretty solid in supporting there authenticity... don't know if he is still around but maybe he will weigh in.

Colossal is correct in his story on the Rocking Class scenario... Dave Thomas is the son of Pat Thomas - CEO of Pacific. Before his arrival on the scene, I had access to the actual engineers at Pacific and even had a note from Pat Thomas himself telling a little bit about the origins of the Pacific tranny set. Pat's key comment was that they only made one set of specification trannies for Ken Fischer - same set was used in the Express and Liverpool. In talking with the Engineers I was able to get the specs on the TW part number, a second that I think was a Two Rock part number, and a third that was an Allyn Meyers part number. The engineer I talked with looked up the specs on all three of them and told me they were all identical with the exception of the color of the bell covers... I think Allyn's were grey bell covers. The spec on the OT was a 6.6K secondary.

In the early days they agreed to sell me the TW spec trannies with the old TW part number on them. Later after TW went back into production Pacific said they couldn't do that any more but they wound me an identical tranny with my own part number on it.

At one point in these discussion they did tell me that John Mark over at Trainwreck did not use the original spec trannies but had his own part numbers... maybe one of these was a 7.5K OT? They would have more credibility if their PT didn't have a spec of 100mA on the HV tap... that's not likely.

As near as I can figure the original PT was a clone of a TV transformer (that was a story I got from the shop at Mercury Magnetics)... which explains why there is a 10 amp heater tap to handle all the tubes in a TV. Colossal was correct in his note about the OT being a clone of a Stancor A-8301... I think it was John Mark that confirmed that for me. An interesting note is that the outputs on the old Stancor's was 4,8,15 ohms... I'll see if I have one of those in the shop and look at the label again.

FWIW, I like the sound of Mercury Mag and Heyboer OT's better in an Express build but I'd be curious if anyone can hear anything special or even different in one of those new 7.5K Pacific OT's??

[WhopperPlate]

Collosal

I could feel that, no worries mate I appreciate the input tremendously

RJ, as I do with you as well, thank you. It’s definitely a mind bender of sorts … the inconsistency compared to the known declared values deviates from the norm with other transformers as well … I am genuinely trying to understand

[WhopperPlate]

Sounds like we would all love to hear Rob Hinson’s input

[2tone]

Certainly a mystery case.. When I used to talk with Ken, mostly weekly, and take notes on stuff he said, trying to learn everything about amps, I had written down in 2 different places in my notes that the Liverpool (and I assume Express too) OT was 5.6k.. So when the word came out about 6.6k I thought it was an error at first.. Now I'm just as confused as ever..

[WhopperPlate]

Certainly a mystery case.. When I used to talk with Ken, mostly weekly, and take notes on stuff he said, trying to learn everything about amps, I had written down in 2 different places in my notes that the Liverpool (and I assume Express too) OT was 5.6k.. So when the word came out about 6.6k I thought it was an error at first.. Now I'm just as confused as ever..

[RJ Guitars]

At some time around 2008 when I first started to gather info and learn about amps and Wrecks in particular, the standard for a Liverpool build was generally said to be a Heyboer with a 5.2K secondary. In later years that belief seemed sorta shifted when it was clear that the later Liverpool and Express amps were using the same 6.6K Pacific output tranny.

I still have a Heyboer HTS-9633 OT-5200 that sounded really good last time I used it. That was about the time that Moose (Toneslut) pulled away from supplying Heyboer trannies and gave me his blessing to offer them from my shop. I recall talking on the phone with Phil at Heyboer and he told me he had his dads design notes on this part number in his hand at the time. He said it mentioned working with Ken Fischer on the development of this... no way to verify the real from the imaginary but it does add some color to the story.

[RJ Guitars]

From the latest marketing email that Pacific sent out:

Our First Consumer Direct Brand
At the beginning of the year, Pacific Transformer launched its first direct-to-consumer brand in its 40 year history called Pacific Audio Magnetics. The brand focused on products for professional musicians and came out with a line of power and output transformers for some of the most iconic guitar amplifiers ever built. Our aim was simple: build the best sounding magnetic components possible. In order to achieve this goal, we partnered with renowned amplifier builder George Allessandro to help develop each part, and the response has been tremendous.

[gktamps]

TW PT on their spec sheet: 250 or 280V per leg.
OT at 7.5k based on Pac Trans testing the part number they say Ken used?
Has anyone here built an Express or Liverpool with a 7.5k OT?
https://ampgarage.com/forum/viewtopic.php?f=6&t=35007