Planning up for a new rocket build - help needed

[jimmy74]

Hi folks I'm new to the forum and I'm glad to have found it. I have a customer that may be looking at getting a trainwreck rocket clone custom built so I looking at gathering up all the information I can find inorder to find out which options would be the best. I've heard that Heyboer trasformers are the best match, though unfortunately for some reason their site doesn't work, so I'm wondering if anyone would be able to help me out. Any and all opinions are extremely welcome and would help me find what would be best for my customer.

thanks
J.

[overtone]

j. welcome aboard!
I ordered the Rocket Heyboer transformers from RJ who is a major contributor to this forum:
http://www.rjguitars.net/
He has supplied often to Europe and can advise you very well.
One thing to watch out for is sometimes the 5 Volt tap is not included on the export (230V) Heyboers.
If you don't need to use the Heyboer iron then arguably the two best producers in Europe are Sowter in UK and I.G. Wickeltechnik in Germany.
I have also used the 4k 36W OT from Ampmaker in the UK which worked well.
Best, tony

[RJ Guitars]

Another good option on the other side of the pond is to use the VOX AC30 iron. It runs a little hotter voltage than the typical Rocket but there is some new evidence out that indicates maybe the original Rockets run a little hotter than our clones anyway.

rj

[M Fowler]

Yes generally 250 or 260v has been considered the appropriate range to use for years but I actually have used as high as 300v Heyboer. In your neighborhood I would use the AC30 as rjguitar said its 290-0-290 with 4k OT.

Mark

[RJ Guitars]

I used Dagnall Transformers that were sold as OEM replacements when I did this a couple years back. Also notice that I used can caps. I had a Voltage control module in it for a while as well.

One cool thing about the VOX power transformer I used was that it could be wired parallel or series to accommodate either 120 or 240 volts.

hope this helps,

rj

[rawnster]

+1 using RJ's stock of Heyboer or Pacific trannies. Use a Heyboer PT, and Pacific OT. You could even use Mercury Magnetic trannies. I recently built a Rocket using the standup versions of their VXO-30M OT, and MMP-V30W PT. Sounded fantastic.

[Matt D]

What is the evidence that the original PTs might have run a little hotter?

[passfan]

I have built 3 or 4 Rockets with the B+ around 400 + volts , with 6L6GC's for the output and they have a lot more chime than the traditional Rocket.

[M Fowler]

What is the evidence that the original PTs might have run a little hotter?

Documentation of original TW amps Rocket, LP and Express show there were many different brands of transformers used with various degrees of voltages.

It all depends on what you want. I personally think using 280-0-280 Pacific with the A-470 OT and Hammnond 158L would probably be the most accurate Rocket but not necessarily the best PT to use.

I prefer Edcor and the last Rocket I built used Edcor PT and OT. I forgot rjguitar has an Edcor choke or I would have used that as well.

Mark

[RJ Guitars]

What is the evidence that the original PTs might have run a little hotter?

The more recent efforts on researching this was done by some others here on the forum and they have shared some of those results with me but I'll leave the specifics to them to disclose. This info does align with some of my early findings and confirms the stories that Ken Fischer's genius was never baffled by the limited parts he had available to him.

The news that is most interesting in studying these amps is that in some cases, the quad of El84 output tubes was ran at a higher B+ than we first believed.

FWIW - As many of us morphed the Rocket to include a compliment of Octal output tubes it only makes sense that a variety of voltages would be appropriate. My first octal Rocket (what I call the Rockster) was based specifically on some of the data scouring that I did and my inclination that Ken Fischer would have done this himself if his health had not failed him... this is not a fact, but my own speculation.

rj