I need a pair of very large output transformers for a 165 watt push-pull tube amplifiers......These transformers need to have insulation for 1000 volts, Primary of 6.5 K, A special output winding at 4 ohms for feed-back......And be of at least peer-less quality........Probably around 15 pounds...........Anybody know anybody that has that or can build it ???    THANKS 

Showing 3 responses by trelja

I have had custom transformers wound for me for tube amplifiers many times, Will.  I've had the best experiences with Edcor and Classic Tone / Magnetic Components.  Some of that depends on whether you prefer plastic or paper bobbins.  Heyboer is also a decent choice, though I prefer the other two.  Folks recommended Merren to me, but I have no experience with them.  I used to think Weber fit the bill as well, but found out their transformers are imported, so custom work is unlikely, and in your case, I cannot see it happening. Though Canadian, you might look into Hammond, which offers off the shelf units, and make some pretty big iron which might suit you.  Due to the exorbitant cost of shipping, I otherwise avoid foreign outfits.

For what it's worth, there are more expensive / upscale like Mercury Magnetics, and even more esoteric outfits like Electra-Print, and Dynaquest.  Honestly, I don't recommend going that route.

Just out of curiosity, do you need a UL tap?
@autospec Will, please give Classic Tone Transformers a call as well. Both they and Edcor do custom work, and take those needs seriously. Heyboer also seemed willing, but again, my results with them fall behind the other two. The rub I had with Edcor was in setting up an account, I needed to provide them far more (government issued information - federal and state tax IDs on official letterhead) than I did with any entity I’ve ever dealt with to prove I was not just a hobbyist. I have my own thoughts on the more esoteric winders as well as ultralinear taps, but I’ll hold them for now.

In regard to your feedback winding, is it possible they get tripped up by your nomenclature? Are you actually requesting a completely separate winding, or just the typical 4 ohm tap to run your feedback loop off? If the latter, they churn them out that way all day long, and should add but a couple of dollars to a single tap output transformer. A separate output winding would be different than most audio or guitar output transformers even if their power transformers get built that way, and my question then becomes, do you truly need a solution that elaborate?

@autospec thank you for following up, Will. Unfortunately, it happens so rarely.

I'm really happy Edcor could seemingly provide what you wanted.  Hopefully, they work out as you want