Rate the Express output transformers.

[2tone]

cloning vintage power transformers that were designed for 115 V or less, can cause high voltage and overheating in some botique amps. Especially with Vox AC 30 types, as Matchless found in the early stages of production, necessitating fans, and higher cathode resistors etc...And some problems with capacitors being damage from high temps in the chassis..

[Finom1]

Hello,

Does anyone know the part numbers of the Heyboer Trainwreck Power & Output Transformer's?

It would be a great learning experience for me to know the truth about the Heyboer Trainwreck Transformer's!!!

Thank everyone for sharing your wisdom here. It has been a great learning the details about the very special amplifier sound!!!

[RJ Guitars]

I finally got an order confirmation from Pacific and they are going to sell me the traditional product that I've had in the past. I'm not planning to offer them off the website or ramp up the business end of things but for folks that want the old spec Pacific Wreck trannies I'll have some around.

I'm also working now on a build with an affordable alternative set of transformers using a Heyboer OT and a Hammond PT... I'll post anything I learn on these.

[jeffkt]

Opinions of Edcore trans please
Thanks

[gktamps]

I did not care for the Edcor OT I got for a Rocket build. Yanked it out and put in a Pacific.
I've used Edcor for other amps and they seem very nicely made and finished.

[RJ Guitars]

I've put Edcor output transformers in an Express, a 15W Liverpool, and my own Rockster amps. If there is such a thing as "Too HiFi", that applies to the Edcor in the Express. It had a bland simple sound to it. I liked the 15W version a lot better... can't tell you why but it had a pretty cool distortion and much more flavor than the 35W I used in the Express. In the Rockster the 35W was again a little too sterile sounding. I suspect this is due in part to the fact that Edcor uses only M-6 steel laminates. IIRC the Pacific uses M-19 steel and I sorta think the Heyboer does as well. I can't tell you what the old Stancor's used but I'm sure with some digging you could figure it out. If you are making a stereo amp for your home sound system the Edcor's probably are a good choice.

[RJ Guitars]

Here is a look at the Express I built using Edcor transformers. As somebody mentioned the Edcors are cosmetically nice looking and they are also unique in their blue color.

[jeffkt]

very nice work!

[jeffkt]

i just built another express with a 6.6k primary output. (heyboer)
Pacific 7.5k sounds good but different then an express
Now the amp sounds close to a real express
Their power transformer also has to low a B+
I will install the correct power trans (heyboer)
that should make the amp as close to an Express as you can possibly get without being Ken Fisher himself.

[RJ Guitars]

I finally got things rolling with the folks at Pacific transformer again. They have agreed to sell me a dozen each of the original spec Wreck transformers... just the same as the past few years. I'll sell some and tinker with some and it sounds like they are agreeable to sell me more if I want them.

Meanwhile I've come up with a theory on the new Pacific offerings: Could this be what John Mark is using in the new half power Wreck trannies? 100mA winding on the PT and 7.5K winding on the OT?

https://www.youtube.com/watch?v=IG0SUAMGXO4

[RJ Guitars]

I found an old link that demonstrates an Edcor tranny set in a TW Rocket clone amp.... which brings me to say that how good something sounds depends on what you like and and who's playing the guitar. I had forgotten about this build and clip but was happy to stumble over it again.

This clip sounds like great tone to me once he gets things going the the sound of the amp is really good.

See what you think of this: https://www.youtube.com/watch?v=z_mDl_50KiQ

[gktamps]

I finally got things rolling with the folks at Pacific transformer again. They have agreed to sell me a dozen each of the original spec Wreck transformers... just the same as the past few years. I'll sell some and tinker with some and it sounds like they are agreeable to sell me more if I want them.

That's good news. Only Express/Liverpool, or Rocket as well?

Meanwhile I've come up with a theory on the new Pacific offerings: Could this be what John Mark is using in the new half power Wreck trannies? 100mA winding on the PT and 7.5K winding on the OT?

Well, he's still using EL34s in the half-power Express, so I'd think the PT is putting out less voltage as well to drop the output power by half. Do you think the 7k5 secondary would aid in cutting power?

I guess the OT at 7k5 would be fairly close for the Liverpool and Rocket with 2 EL84s, but it seems like an odd choice to me.

Still trying to reconcile the reported comment by Pacific that their current specs are what Ken actually used.

[Roe]

got the following response from Pacific:

We were originally told by Ken Fischer to make a 6.6K ohm transformer for his amps.
After tweaking the transformer to match what he wanted on his amp, we didn't measure the new impedance.
Now that we are getting into the audio industry, we are doing our best to give our customers the most authentic and real vintage specs.
I believe there are 2 reasons why you see manufacturers with the 6.6k:
1) Since we started prototyping the 6.6k ohm transformer for Ken, I believe he went shopping around other manufacturers and asking the same thing.
2) Our quote and old spec sheet still had 6.6k and were passed around the internet.
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.

[RJ Guitars]

got the following response from Pacific:

We were originally told by Ken Fischer to make a 6.6K ohm transformer for his amps.
After tweaking the transformer to match what he wanted on his amp, we didn't measure the new impedance.
Now that we are getting into the audio industry, we are doing our best to give our customers the most authentic and real vintage specs.
I believe there are 2 reasons why you see manufacturers with the 6.6k:
1) Since we started prototyping the 6.6k ohm transformer for Ken, I believe he went shopping around other manufacturers and asking the same thing.
2) Our quote and old spec sheet still had 6.6k and were passed around the internet.
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.

Interesting... The Pacific and many other clones were modeled after the Stancor A-3801 which was a 6.6K primary and curiously had 4, 8, and 15 ohm secondary taps. There are a few clones out there with that same spec including the 15 ohm tap. I talked with John Mark about that one time and he said that the best sounding trannies for a Ken Fischer build was the Stancor A-3801 and the older the better it sounded. IIRC, it was during that conversation that he said the Pacific was intended as a clone of the Stancor.

[RJ Guitars]

I don't have a copy of that document that they mention - I've seen a few but nothing that clearly connects the Pacific part numbers and Ken Fishers work.

Rob Hinson can probably shed more light than any of us but IIRC the Wreck trannies that were produced over at Heyboer were reverse engineered from an actual Wreck build - with a 6.6K primary.

Then suppose we buy their declaration at face value, it still doesn't really make sense that the Official Wreck Power Tranny has a 100mA HV tap. That just sorta drives the doubt in my mind that they are really on top of things concerning the specifications.