Rate the Express output transformers.

[Finom1]

Does anyone know what transformer is used in the Ceriatone Expression amp?
http://www.ceriatone.com/tw-clone-expression/

At this price point, who builds the best sounding Expression with that warm growl and singing sustain I love?

The sound I am looking for:
I like the singing clean harmonic rich sound of the of this clip, 1959 Gibson Les Paul + Trainwreck Amp tech talk w/ Glen Kuykendall - https://www.youtube.com/watch?v=Uc3Xi6aAG80

This is what I want to sound like, Leslie West in the early years, Mississippi Queen https://www.youtube.com/watch?v=VbP4qf8PjfI

Thanks, everyone, for sharing!!!

[RJ Guitars]

The kind words are appreciated... I learned a lot from those that went before me and I'm still a student searching for missing pieces of the puzzle.

What I think is true is that the primary and secondary windings of an output transformer are provided to us as ratio that is typically based on the 8 ohm tap (for a multi tap tranny). There are some frequency dependent elements that make this ratio a bit of a moving target, but for practical purposes it's close enough. So if you want to know what the impact of changing that ratio is you can listen to an amp under the same conditions and switch between the 4, 8, and 15 ohm taps. This isn't a perfect test but it will tell you something about the impact on tone at the extreme of input/output ratios. This is a much greater difference that you'd have between 6.6K and 7.5K primaries.

A couple cautionary notes: if the OT switch doesn't ground while switching between taps you'll be sending energy into an infinite-ohm load between taps and bad stuff can happen. So real time switching isn't recommended unless you are using a grounding type switch. Otherwise, put the amp in standby or turn it off when you switch it. Also be aware that if you get too far away from the engineering specs you can ruin your transformer. Gerald Weber published a note at one point where he declared that if you are within 100% of the appropriate ratio you'll suffer no failures. So from the 8 ohm tap to the 4 or 16 ohm tap puts you right at the 100% specification and you should be fine according to Gerald Weber. Can't confirm this is entirely safe but at the time nobody really argued with him about it so I expect it's reasonable. I've played with it a bit and the difference in power is obvious while the difference in tone is a lot more subtle.

Somebody let me know if my understanding is flawed, but that's the story I've got until I understand better.

[gktamps]

I've just had a forum member share with me an excellent sound file made with his 7k5 Express build. Great guitar, drumming, tone, recording. I've suggested to him that he post his impressions of the amp here, because whether one agrees or not that this has the quintessential TW Express sound, I found it to sound excellent. As I wrote to him, I found it rather Marshallesque - lots of grit and tight, but with undertones of the TW chime. The track didn't include much in the way of rolled off volume on the guitar so I couldn't tell how much the amp cleans up, but I did hear some nice, subtle harmonics. Hopefully he'll share the sound file and pictures of his build with the forum, along with other details of the recording - guitar, pickups, pedals if any, etc.

Pacific Transformers has stated, as reported earlier in this thread apparently, that they were provided 6k6 as a spec by Ken, but they then "tweaked" the specs but still labeled it as 6k6, which if accurate is interesting, to say the least. Even if that turns out to be incorrect, I'd definitely build another Express with a 7k5 OT just for a change of tone compared to my two 6k6 builds.

[Roe]

Someone should measure an original TW express with a pacific OT.

[Finom1]

As QUOTED, " As I wrote to him, I found it rather Marshallesque - lots of grit and tight, but with undertones of the TW chime."

Why would anyone looking for the Organic, Harmonically Rich sound of a TW Express settle for a " Marshallesque" build. To me, is a waste of money.

I had one of the first Marshall Lead 2000 250 amps directly from England and that is not the sound I am looking for. That sound is missing the magic!!!

Pacific with 7K5???

[Finom1]

Corespondance with Jeff at MM, gave me this information:
"TW-KF-OT mounting dimensions: 2.50” x 2.25” Trainwreck | MISC. | Output Transformer, Dual primary — 5200Ω and 6600Ω — 4, 8 & 16Ω taps — Upgrade! - https://www.mercurymagnetics.com/produc ... ransformer

Thank You,

Jeff Guzman"

Can someone please add detailed information on the tonal differences using an MM transformer as compared to Pacific's?

I like the singing clean harmonic rich sound of the of this clip, 1959 Gibson Les Paul + Trainwreck Amp tech talk w/ Glen Kuykendall - https://www.youtube.com/watch?v=Uc3Xi6aAG80

Thanks to anyone who can provide data and video evidence on the differences!!!

[gktamps]

Why would anyone looking for the Organic, Harmonically Rich sound of a TW Express settle for a " Marshallesque" build. To me, is a waste of money.

I hear you - I have built a JTM45 and a modified JCM50, and my TW amps are what I almost always prefer. That was just my attempt at describing a sound file, and you might hear it differently. It definitely sounded like an Express, but with a bit more compression, and very chunky, if you will, but still with the Express chime and character for sure. One clip can't display all of the variability and ability of an amp at different settings, through a speaker cab, etc. It's difficult for me to accurately describe, so hopefully I haven't left a turd in the punchbowl.

After my post I learned the amp was recorded through a UA OX attenuator, which might account for some of the tonal character I heard, but this is only one sound file, and probably shouldn't be considered to be the full spectrum of the amp's sound.

But let's focus on this question; is PacTrans actually saying that the final, "tweaked" spec for Ken's OTs was 7k5 but they just kept describing them as 6k6? That is what interests me. That would be very nice to confirm or refute, for obvious reasons, would you agree? And how is changing spec from 6k6 to 7k5 just considered "tweaking"?

[gktamps]

Can someone please add detailed information on the tonal differences using an MM transformer as compared to Pacific's?

I think RJ described in this thread some of those differences he observed.

[jeffkt]

ok here is my express clone with the 7.5k Pacific output transformer.
It was recorded using a Universal Audio Ox Box
will be working on a more transparent recording to follow using a real cab and microphone

here is the link
https://youtu.be/7lCBHSjcaOQ

[RJ Guitars]

That is a good sounding clip. I hear nuances of some Dokken in there. George Lynch was supposed to be one of the early Trainwreck users so maybe you're onto something there. Thanks for posting that.

The sound difference I hear between a Mercury Magnetics OT and a Pacific OT in an Express circuit is pretty simple to define.

The MM was warmer which I think is due to some added harmonic elements and maybe a bit more juice in the midrange. They sounded good in the transition from clean to mean and that transition was fairly linear as I would crank the gain up. My favorite tone ever came from an old Marshall 50 and that MM tranny in a Wreck sounds very similar... so a persons taste of what is good is relevant.

Each Pacific I tested always seemed to have a darker simpler sound which I think is that it has a bit of a dip in the mids compared to the MM. It also had more of a knee when you pushed it to break up. The breakup also occurred sooner than it did with the MM tranny. This dark full sound and is what I think of as the distinctive Trainwreck sound.

It's also important to note that my ears, guitars, and playing isn't going to be identical to anybody else. I recently read a book on EVH where he talks about Ted Nugent playing through Eddies rig and it sounded entirely different.

[ChopSauce]

For the sake of completion, because that thread seems pretty usefull:

I can't remember where I could read some that an Hammond 1650G(*) output transformer (6k6 primary, 35W) was being used on an express build...

Any comments?
_
(*) https://www.hammfg.com/files/parts/pdf/1650G.pdf

[Finom1]

Yes, that was a great clip and if you want a Marshall sound, have fun with it. Just another Marshall clone. I had the one of the most powerful and articulate amps, Marshall made and sold it. Not my sound, the EVH brown sound is great, but not the organic warmth of a TW Express. That is what my ears are totally hearing without question!!!

Thanks for making the differences so clear to me now!!!

[Finom1]

Hello,

Does anyone have a TW Express clone video of one built with Mercury Magnetics TW-KF-PT & TW-KF-OT transformers?

Bless everyone for the detailed information on the sound and feel of different transformers!!!.

Someone sent me this message, " Plus, he didn’t use Pacific exclusively. Lots of the TWs used Dynaco or Stancor as well."

Does anyone have part numbers for P.T. & O.T for both manufactures so we can look at their respective spec sheets?

[jeffkt]

I can confirm that in original 1980s train wreck express output transformer measured at 6.6 K

[jeffkt]

http://marstran.com/Measuring%20Primary%20Impedance.htm

A method similar to this was used
I confirmed this with the owner of the amp