Opinions welome! Various OTs for the Express

[Jackie Treehorn]

I bought an actual trainwreck power transformer from eBay around 8 or 9 years ago. 3 taps, 250, 275, and 300 volts at 250ma. It's in my rocket type amp. I posted the part number previously.

There's a Heyboer output transformer that has the exact Pacific part number 11415 (not exactly sure on the number) in it's Heyboer code. I think it was the second transformer used for the very early clones, 6.6k. Thats the one I like. The prior one, i think, was 5.2k. That uncertainty early on whether the Express was 5.2k or 6.6k is where the multitapped output transformer came from.

[RJ Guitars]

RJ, since you don't sell the Heyboer any longer, besides MT, who is? I do remember now that you took over the Heyboer thing from Moose. Did Edcor just fit your needs better? Eh, I know you can't sell it all, of course.

Ross, I had to choose at some point one transformer set to carry as the "the traditional Wreck transformer". Heyboer did a great job early on and were easy to work with. I think the sound of them was extremely good also. I will admit that I had some QC issues with them and it got to the point that I decided to go with Pacific and EDCOR... I won't elaborate here but it was more of a choice between a couple decent options more than it was eliminating a bad one. MojoTone has them covered for the folks that prefer them.

The Heyboer "Vintage" trannies were intended to be smoother than the original formula - making them similar to the Pacifics. I still have a lot of their stock here, especially the euro voltage stuff.

Dual taps just seem to be popular, although I don't think any of the old vintage transformers had them. FWIW - with the EDCOR in an Express, the 5.2K tap is preferred.

This is a good thread, I appreciate the info sharing that is going on, especially from some of the old TAGgerz that know the history.

[rp]

What I'm very curious about is why no one offers a bog standard clone of the original Stancor A3801? My knowledge is only what I learned from TAG but isn't the Stancor what KF used till he had trouble sourcing them and then started playing w/ his own recipes and winders? Until this post this is what I thought everyone here was working with, I didn't realize everyone was trying to make a version of the post Stancor KF secret recipe. I'd be very happy with a very accurate clone of an A3801 and I think this was what rooster was getting at. Anyone know if this is an option if you contact Heyboer or Pacific directly? What is the MC, an other inferred secret recipe or A3801 clone? Heck if I ever find a blown one cheap I'll send it to Heyboer for a blueprint and rewind myself, wish I'd done this while I was still in the States.

[cap217]

I find it interesting that MM doesnt give specs. I understand their confidentiality and all of that but they wont share specs but have a KT TW transformer that is NOT based on the transformers Ken got? They say its close and what THEY think would sound best in a wreck.

Its just weird how they word it. All so cryptic.

[Jackie Treehorn]

I think Richie posted this transformer test awhile back...

http://www.one-electron.com/Trans_Tests.html

The Stancor has the worst bass performance. It also measures 7.6k, which I hadn't noticed before. It would be very interesting to know how consistent they are in that respect. hint hint hint!!

It is in a feedback loop, so one could speculate that on the low end, it acts like a bit of a resonance control, increasing gain at low frequencies. Under full power, the low -3db looks like 62hz in that test. Pushing the impedance up to 7.6k might roll off a bit more top.

It wasn't even the best transformer Stancor made. I think the problem with cloning it is that you'd have to find someone that could duplicate a particular poor performer, rather than build a really good one.

[Drew.12345]

I'm confused here as Mercury specs for the their TW PT and OT are posted on their webpage???
If you click on the trainwreck logo and it's all there.
I don't believe they are trying to hold specs back on this iron at all.
It is definitely not a clone of a stancor or pacific but it's what they feel would sound best in a wreck circuit.

I've called them to discuss it and they haven't held anything back and openly admit that it's in no way affiliated with a Ken line card from the past.

Andrew

[rp]

I think the problem with cloning it is that you'd have to find someone that could duplicate a particular poor performer, rather than build a really good one.

Maybe it could be made in China

From the pdfs it looked like they tested the pz themselves so it was pretty far off. Maybe it was a bad example, maybe that was why KF tried different ones from his stock till he found one he liked?

my head hurts.

[RJ Guitars]

I think you guys got it right... The problem gets down to not a specific brand or model but rather the individual characteristics of a given tranny. I asked EDCOR if they would clone one for me. They simply said no, we aren't interested... And they elaborated - to paraphrase "those were rather cheap transformers wound using old school materials, winding equipment, and assembly techniques... we can consistently provide a better transformer with better specs using our own winding techniques and modern materials.

If you do dig down to see what the old Heyboer or Pacific "Wreck Spec" iron is, it's going to look a lot like a Stancor A-3801, including the mysterious 15 Ohm tap with the Pacifics. However, no company is ever going to confirm that for a variety of reasons. I expect MM has taken a similar stance to EDCOR, and they are admittedly well made good sounding transformers. I would put my money down in a heartbeat in betting that KF could have made an awesome sounding Wreck with a set of MM TW transformers.

My last speculation here is that if you made 6 identical amps and used 6 different A3801 output trannies, they would all sound different where as with the more modern trannies that might not be as true... My own guess based on no significant data. I do think we get wrapped up in trying to make an exact clone when Ken Fischer himself individually tweaked each amp to to the unique taste of the buyer... Keeps the mystery open as to what a Trainwreck really sounds like?

rj

[rooster]

Good reading.

I have purchased and received a Pacific OT from RJ and now installed it in my 'big' Express. (Thanks RJ and son!) I have put about 8 hours on it at this point so I think I should run it for another day or two before I write a review, just to be fair. At first blush, however, this seems to be a good fit for the Express, as others have said. It has a bit more headroom than the others, a slightly more *masculine* tone. (That's the word I'm using, yes.)

[rooster]

OK, we brought the Alan Philips (Carol-Ann amps) Express clone over here again today to get a perspective. Now, I should point out that it was this very amp, the Philips clone, that got me into the Express about 6 years ago, and, the amp that sounded tighter than mine when I ran the Moose/Toneslut Heyboer OT two weeks ago. The Philips clone uses the MojoTone Heyboer tranny set, BTW. I think he called this model the 'Fat 30' and the back panel says as much.

But we need a bit more info on both amps. His pres are: Amperex V1, Telefunkin smooth plate V2, Mullard V3. The power tubes are Siemens and biased to 45mas

My tubes are: GE12AX7 V1, Ken-Rad long black plate V2, GE12AX7 V3. The power tubes are Mullard xf2s and biased to 28mas.

(Note: My tubes were: Tungsram V1, Ken-Rad long black plate V2, Sovtek 12AX7 R2. My power tubes were J/J KT77s biased at 40mas.)

Alright, two weeks ago we A/B'd these amps and I liked the Philips clone better. To help explain, my friend left here thinking he had stolen the Golden Goose.

Today, this was not the case. He easily had to concede that his bias is too hot, something he disagreed with at the time, so we will change that next week sometime. But then there was the quality of the 'grind'. To both of us it was clear that there was a roundness to the Pacific that was not in the Heyboer. The Heyboer was just more edgy, somewhat agitated when compared to the Pacific. It may be very hard to explain in words, but standing there listening, it was very very easy to hear for both of us. Using a LP with HBs, neck or bridge pickup, the Pacific equipped amp running at volume 10-11 sounded well, like your recollection of the best Beano album track you can think of. This was into the Brad Paisley Weber pair in a 2/12 semi closed cab.

I'll be back with more, and I'm sure you are wondering about the bias number on my tubes. This is something Gregg Levy/Hi Test Guitars (a friend of Ken's and also someone who owns a few TWs) talked to me about. He said I was going at the Express all wrong, that I should get over the 40ma number touted on TAG.... Well, I argued with him - carefully, because I respect his opinion - but today I have to concede his point. Now, I will also add, the Tele and Strat are not behaving like they used to (they need a bit more gain), but to hear the HBs like this I am very much in shock mode right now. The thing is, since I dig the 808, I am not too worried with the trade off with the SC guitars. Yeah, I have no problem using an OD with SCs into this amp in a small club.

Well, you need sound clips so I will do this next week. Also keep in mind, all this Tranny swapping and tube swapping is about me trying to get to the 'real' Express. It's not that I thought I was limping along (but I was), but I just thought there was more to it. Slowly I turned...