Trainwreck PT and OT originals. I have em!

[RJ Guitars]

I received my new set of original part number and specification TW transformers today... here is what they looked like and also a series of photos showing each of them side by side with the K&M Analog units that we are all familiar with. I additionally did some voltage measurements and put together a comparison chart of the two power transformers.

[redshark]

I don't believe our parts were ever used for a Rocket. May be a Heyboer.

I know they were. The owner of the amp told me.

[RJ Guitars]

questions:
What would be the actual difference between a 5V filament vs 6.3V?

Asking questions like this will bring into the brotherhood of TAG amp builders... this is the stuff we love to answer... In this case you gotta study rectifier circuits... more on that to come later.

I don't believe our parts were ever used for a Rocket. May be a Heyboer....

Well, that is true, not in an original Rocket but Pacific transformer does make what I believe is at this time the finest Power and Output transformer set available for a Rocket amp... see if these look familiar to you: http://rjguitars.net/Pacific_Transformers.html

IIRC Allyn Meyers also has you winding tranny sets for Rocket builds and there are likely others here on this forum who also provide products from you...

[RJ Guitars]

I don't believe our parts were ever used for a Rocket. May be a Heyboer.

I know they were. The owner of the amp told me.

True for the modern JM builds... of the few that we have documentation for the originals the PT info is scarce but the Dynaco 470 is typically declared as "The Rocket Output Transformer". I suppose JM could be copying one of the originals that used the Pacific iron without the 5V tap, but according to Pat Thomas, they never made a TW tranny with a 5V tap?? Maybe a prototype?

Ah the fuel for the mystery and mojo remains in the elusive details of the whole truth....

[RockingClassElectronics]

Wouldn't doubt we've wound transformers for a Rocket build, and then again amp companies don't tell us jack about what the parts go into haha. All I have are a set of numbers n specs...and production codes.

[RockingClassElectronics]

I'll you something about Pat Thomas
He knows all about Ken's parts. All the post-Ken parts were handled by our team of engineers and sales staff. SO he could be wrong, but thinks he's got it all down -signed, Dave Thomas. Remind me what to look for, and we can figure this all out on monday when I once again tear into some files.

I get the feeling JM hates buying from us. He keeps threatening an intellectual property war... He doesn't own the part. We do. And we can sell it to whomever we want. he recently shut me down on ebay.

HAVE A ROCKIN' WEEKEND, ALL! If you get to touch your guitars this weekend then I already envy you. I have a bunch of RV transformer parts to make tomorrow and sunday, but I will try to get back to anyone needing anything on this forum.

[RJ Guitars]

Before the days of modern solid state diodes, AC voltage was converted into DC voltage using tube diodes, aka rectifier tubes. As with any tube these require a heater to give off electrons and make things happen (yes i know I grossly understated that). In the case of most tube rectifiers they use a 5 volt heater winding that is independent of the 6.3v heater winding for the rest of the tubes.

The Trainwreck Rocket is essentially the Top Boost channel of an AC-30 amp, which uses a GZ34 rectifier tube... arguably the best tube rectifier ever built. It could be replaced with modern diodes but it's part of the mojo of the AC-30 and Ken Fischer kept it in his Rocket amp.

[redshark]

I don't believe our parts were ever used for a Rocket. May be a Heyboer.

I know they were. The owner of the amp told me.

True for the modern JM builds... of the few that we have documentation for the originals the PT info is scarce but the Dynaco 470 is typically declared as "The Rocket Output Transformer". I suppose JM could be copying one of the originals that used the Pacific iron without the 5V tap, but according to Pat Thomas, they never made a TW tranny with a 5V tap?? Maybe a prototype?

Ah the fuel for the mystery and mojo remains in the elusive details of the whole truth....

If the specs of the Stancor P-8378 were given to pacific then that transformer could be used for a rocket without the need of the additional 5v filament transformer.

[gktamps]

[/quote]
True for the modern JM builds... of the few that we have documentation for the originals the PT info is scarce but the Dynaco 470 is typically declared as "The Rocket Output Transformer". [/quote]

The last time Allyn made chassis and transformers available to the group, he indicated to me that the original Dynaco OT I was thinking of using was actually not correct for a Rocket, but that the transformer he was offering were more correct. He didn't provide any additional details.

Cheers,
Greg

[RJ Guitars]

...If the specs of the Stancor P-8378 were given to pacific then that transformer could be used for a rocket without the need of the additional 5v filament transformer.

I think you are on to something there... I had always heard that the early Wrecks used Stancor power transformers but I hadn't tracked down that part number... that looks like the ideal spec for a Wreck PT. I suppose those are among the various forms of unobtainium that we are looking for.

....The last time Allyn made chassis and transformers available to the group, he indicated to me that the original Dynaco OT I was thinking of using was actually not correct for a Rocket, but that the transformer he was offering were more correct. He didn't provide any additional details.

Cheers,
Greg

I've got some unsubstantiated evidence that would imply the same thing... but it's not a bad choice for sure?

Curiously on the one JM Rocket we've seen the insides of, it appears he was using the Dynaclone or one of the modern versions of the A-470. There is a thread here on TAG somewhere with that info.

[rp]

Mr RockingClassElectronics, how you winding those things?

- paper or plastic bobbin?
- m19/26ga or m6/29ga or other?
- on the PTs for 240V using M6 for 50hz reliability?

sorry if it's probing your secret sauce but it pretty standard info and it is a DIY geek tech forum we are on.

I wouldn't worry about eBay, you should get back on it, just avoid the copyrighted words: Ken Fisher, Trainwreck, Express, Rocket, Liverpool. Dumble too if you're doing those. Just use some easy to understand pseudonyms - TW-EXP etc should do it. You loose the random search / stumble upon ability, but it mostly all DIY word of mouth/forum directed business anyway. Ebay is a very convenient alternative especially for the oversees crowd given the ease of using Paypal and eBay plus ratings and the security people like.

[martin manning]

questions:
What would be the actual difference between a 5V filament vs 6.3V?

Not sure what you're asking here. Physically its just a different length and/or gauge of wire so the filament reaches the correct operating temperature on 5V instead of 6.3V.

I've been looking at some of these layouts and it looks like one of the easiest circuits I've ever seen (Express).

Easy or simple? The Express is a dirt-simple circuit, and because of that there is very little getting in the way of the pure tube tone. That also means it is unconstrained and free to misbehave, so the wiring layout requires extra attention.

Can someone point me in the direction of a good Trainwreck clip? Are there any on this forum?

Glen K is a TAG member: https://www.youtube.com/watch?v=Y2_12Ler9B8

[Zippy]

Can someone point me in the direction of a good Trainwreck clip? Are there any on this forum?

Are you really so lazy that you haven't bothered looking around this website nor YouTube?

You strike me as the frat rat college kid that shows up to a homework session with a bag o' cheap snacks, and expects everyone to share the answers.

[M Fowler]

The Rocket Jovanna has paper wrapped Stancor choke C-1002
75mA, 400 ohms DCR and 15H.

The OT in Jovanna is a dynaco A-470-s.

Another PT used in Rocket was the Stancor P-8356 270-0-270 (260mA), 5v3A, and 6.3v/8.8A

[rp]

Another PT used in Rocket was the Stancor P-8356 270-0-270 (260mA), 5v3A, and 6.3v/8.8A

That's good to hear I bought a 550CT Hammond 370HX which I feared might be too hot but that Stancor was very likely for 115V so it probably ran hot too at modern wall voltages. With that Stancor that Rocket likely had ~340V on the output tubes. I'll stop worrying about what I'll get on the plates, whatever it is is authentic enough.