TW Express...just another clone!

[Tinkerer]

Hi guys,
my first post here so please be gentle. I've been reading posts with interest trying to learn as much as I can about the Express, and you're a wealth of information. I've built a Marshall 2204 and JTM45, and a Fender AB763 Black Face Twin. Now I have a good friend who wants me to build him an Express clone.
I'm hoping I've done the right thing in ordering PT and OT from Brian Wallace at Marstran...his iron is amazing in my JTM45, so I'm hoping his magic continues with the Express, but any input would be appreciated.
My friend also wants me to use Jupiter caps in the build. Has anybody had any experience with Jupiter caps in an Express, or should I use Orange Drops, and if so, which series? The Jupiter caps sound great in my Fender, as do the Sozo caps in my Marshalls, but they are different animals!
Is there anywhere I can source the Mallory Electrolytics, or am I trying to push sh*t uphill with a pointy stick?
All and any help would be much appreciated.

Tinkerer

[JamesHealey]

F&T filter caps are great quality and work well.

I used the SBE Orange Drops PS6 series (polyester ones).

The Mallory were the ones Ken used but these sound pretty much the same imho.

[tob]

If you don't want to build the filter cap stack you could get radial JJ caps (40+20+20+20 and 50+50) but I second James in that F+T caps would work very well. I've used both in Express builds.

Antique Electronic Supply (http://www.tubesandmore.com/) carries 6PS caps. I can recommend Wima MKS4 caps, too. They work like a charm in my builds.

Tobias

[Tinkerer]

Thanks for the quick replies people. I was going to use the F&T electrolytics. I've used them in all my amps so far, and I like them a lot, but I figured that if I could get the Mallorys I'd use them for the sake of authenticity.
If there is no audible difference in tone between the PS6 Orange Drops and Mallory 150s, then I'll stick with the Jupiters as my friend wants as they too are polyester caps, just supposedly better quality. Truth be known, I couldn't pick a difference in tone in my Fender when I swapped out the Mallory 150s for the Jupiters anyway!

Tinkerer

[gearhead]

I prefer going with the originals, but YMMV. Shipping for you might be a big factor.

[dukeamps]

Hello, I just want to say that i have used the marstran trainwreck express transformer set, and have not found any problems with them. As i have never got the chance to hear a real express amp live, only on youtube - and the quality on youtube is not that good, I have no direct comparison. My amp sounds ok. I have put a couple of sound clips on my homepage. I have also got some other clips of amps that i have built there. I have made the clips not so complex so you can hear the difference between the amps. Hope this helps. www.dukeamps.de

[Zippy]

I'm hoping I've done the right thing in ordering PT and OT from Brian Wallace at Marstran...his iron is amazing in my JTM45, so I'm hoping his magic continues with the Express, but any input would be appreciated.

Are the Marstran trannies observing "classic" voltages and impedance?

[Tinkerer]

Dukeamps, your amps sound great, and its nice to be able to compare my JTM45 to yours, although I'm not using the same speakers, I've got a good indication, which makes me even happier about my build. I now also have a benchmark to judge my Express with when it's finished other than the Komet, and my friends (owner of the amp) opinion.

Gearhead, thanks heaps for the info on the Mallory electrolytics. Shipping cost isn't the factor, Canada Post is! Every time I've bought gear from Canada, I pay for air mail, but it may as well be sent by slow boat. Canadian Post is so slow... sorry if I offend.

Zippy, they're not questions I asked of Brian, but if his Marshall iron is anything to go by, then I would have to say yes. I've used a complete set of his transformers in my JTM45 and allowing for fluctuations in line voltage, the voltages were spot on the money. I've also used one of his Plexi 50 power transformers in my JCM800 copy, (chassis uses a lay down transformer), and again the voltages are correct. His OT for the JTM has 4, 8 and 16 ohm taps, and has the 100v tap encapsulated in the windings. His claim is that although the 100v tap isn't used, he puts it in because it affects the tone from original by not having it. If he is that thorough with the Marshall iron, I'm very sure that his TW iron would also be true to classic voltages and impedance... but only time will tell, and like Dukeamps says, without an original Express to compare with, and poor clips on youtube, it will be hard to tell.

Thank you to all of you for the information.

[Roe]

I'm hoping I've done the right thing in ordering PT and OT from Brian Wallace at Marstran...his iron is amazing in my JTM45, so I'm hoping his magic continues with the Express, but any input would be appreciated.

Are the Marstran trannies observing "classic" voltages and impedance?

from using some of marstran's plexi trannies, I would expect marstran to be clones of TW trannies

[geetarpicker]

On the subject of OTs. Brian is quite aware of where the original specs for the Trainwreck OT came from, which is the long discontinued Stancor A-3801. These transformers had a unique core stack and choice of metals, along with yet two unused ohm taps. The earlier wrecks I've seen with the grey transformers had these, though my '89 wreck was made right after Ken switched to the later Pacific OTs. As far as I know the Pacifics were built to Ken's specs, which were basically to copy the discontinued Stancor specs except one detail was changed for sure. The Stancors apparently had 5 output taps, 4, 8, 15 ohm, but also 250 & 500 ohm, plus the 6.6k primary. I'm not sure but Brian @ Marstan may have actually added those extra taps to his clone OT to be more period correct to the earlier wrecks but I'm not sure. I seem to recall he believes the extra winds have an effect on the tone, and is perhaps one of the reasons the original Stancor wrecks sound a bit different than the later Pacific ones. It would be worth contacting Brian and see which specs he followed with his take on a Trainwreck OT.

[Tinkerer]

On the subject of OTs. Brian is quite aware of where the original specs for the Trainwreck OT came from, which is the long discontinued Stancor A-3801. These transformers had a unique core stack and choice of metals, along with yet two unused ohm taps. The earlier wrecks I've seen with the grey transformers had these, though my '89 wreck was made right after Ken switched to the later Pacific OTs. As far as I know the Pacifics were built to Ken's specs, which were basically to copy the discontinued Stancor specs except one detail was changed for sure. The Stancors apparently had 5 output taps, 4, 8, 15 ohm, but also 250 & 500 ohm, plus the 6.6k primary. I'm not sure but Brian @ Marstan may have actually added those extra taps to his clone OT to be more period correct to the earlier wrecks but I'm not sure. I seem to recall he believes the extra winds have an effect on the tone, and is perhaps one of the reasons the original Stancor wrecks sound a bit different than the later Pacific ones. It would be worth contacting Brian and see which specs he followed with his take on a Trainwreck OT.

I've emailed Brain to get the answer to your question and I'll post it when I get a reply...unless somebody else beats me to it!

Tinkerer

[Zippy]

On the subject of OTs. Brian is quite aware of where the original specs for the Trainwreck OT came from, which is the long discontinued Stancor A-3801. These transformers had a unique core stack and choice of metals, along with yet two unused ohm taps. The earlier wrecks I've seen with the grey transformers had these, though my '89 wreck was made right after Ken switched to the later Pacific OTs...

Thanks, Glenn. That leads back to the issue of "What is the 'correct' tranny if Ken changed his selection during the evolution of the Express?" It seems to me that there are easily several correct answers. If the later choice was "superior", does that make earlier Express amps "inferior"? I doubt it.

My favorite multiple choice answer: "E" - all of the above.

[Tinkerer]

Hi people,
Brian Wallace got back to me regarding his TW Express OT. The following is the email from Brian.

"The current A-3801 I make only has the 4, 8 and 16 ohm taps along with a 6k6 primary. I may make a dead on clone in the future if there is a demand for it.

Thanks, Brian"

I think that clears up any questions we may have about Marstran iron for the Express.

Kosta

[paulster]

Heyboer also said that Brian's Marstran transformer was designed to be an accurate clone of the Stancor A-3801 (minus those additional taps) and therefore that's the one of theirs to get if you are going for the Stancor era (unless of course you can get a Stancor).

There were lots of test samples and revisions to reach this point and Brian sets the bar very high, as owners of his other transformers will testify.

So it's nice to have another new production flavour available that is perfectly suited to the Express.

[RJ Guitars]

... so it's nice to have another new production flavour available that is perfectly suited to the Express.

I don't know that it is perfect but for anyone who likes the thought of another flavor of Wreck trannies, I will supply the Express Specification EDCOR trannies to you at cost ($167 per set + delivery) just to get some feedback on how they sound. So far everything has been positive in my experience with these trannies. However, I would like some objective review and experience from the rest of the builders in the world to add in to the equation.

I have a Liverpool chassis with EDCORs in the works that I hope to get together in these next couple months. I'll offer the same deal for anyone who has an interest in this tranny set or a set for the Rocket amp for that matter. I have a few pieces of data on the Rocket builds with these and they sound quite good.

These trannies would likely win any beauty contest for guitar amp trannies... if that mattered. They are very well groomed compared to the Heyboer or the Pacifics that I stock but I would like to add some sonic data to the info file on them.

thanks,

rj