Looking for choices - affordable PP OPTs

[zobsky]

Looking for something around $60 +/- a few dollars. Apart from sounding good, they must be able to work well and deliver sufficient bass response.

1. Apart from the edcors (eg http://www.edcorusa.com/products/tra...0-ms-8_4k.html ) or hammond or dynaco replacement iron, is vintage iron from ebay my only other choice?


2. Does anyone have experience with the edcor Push Pull transformers, and how they stack up to the competition?

3. I thought of using toroidal OPTs (since I have now found an affordable source for them) but haven't made up my mind on that front.


Thanks

[zobsky]

Originally posted by zobsky

3. I thought of using toroidal OPTs (since I have now found an affordable source for them) but haven't made up my mind on that front.

Clarification , .. I meant running toroidal power transformers backwards

[aerius]

I've used power toroids as output transformers for my amp, but it only puts out a couple watts so I'm not sure how they'd work for higher powered amps. Steve Bench also played around with some donuts for his amp, but again it was a low-powered design. I figure if you have a source of bigger toroids you shouldn't have too many issues getting a 30-50W out of the amp. In anycase, I find toroids to be really nice sounding transformers, much better than the Hammonds I got from the local surplus store.

[BudP]

Zobsky,

You are not going to find any first class OPT's for $60 ea. The power toroid is going to give you about 70% of the performance of an E/I OPT from one of the houses where they actually have a designer who knows what he is doing. If you will email me I will give you further information on a pair of the OPT's that Lynn Olson uses in his Karna, an amplifier that Mahatma Jeeves says represents the finest possible modern tube amp.

This is not BS and I cannot say more here.

Bud

[Salas]

For those that might consider the above linked design as a project beyond it being an example of mains toroids used as audio transformers, I must add that the caution introduction paragraph of the author is a very real warning since the schematic does not include a mains transformer and rectifies directly the mains ac like in old TV sets and radios. I was thinking of doing that too in another circuit idea and the members of DIY audio cautioned me very emphatically that such a practice must NEVER be considered as an option. Its a health risk at all times. See the safety sticky thread.

[Shoog]

Used toroidals, very happy with the result. Also used them as phase splitter - less satisfactory, but with the right design these work to. Only putting out about 7watts though.

Shoog

[Eusebius]

If you will email me I will give you further information on a pair of the OPT's that Lynn Olson uses in his Karna, an amplifier that Mahatma Jeeves says represents the finest possible modern tube amp.>>

I know just what Bud is talking about and you'll be more than very pleased with the results - I second the idea of emailing him! Andy

[zobsky]

Originally posted by Eusebius
If you will email me I will give you further information on a pair of the OPT's that Lynn Olson uses in his Karna, an amplifier that Mahatma Jeeves says represents the finest possible modern tube amp.>>

I know just what Bud is talking about and you'll be more than very pleased with the results - I second the idea of emailing him! Andy

I did, thanks

[ray_moth]

A toroid power tranny seems like a possibility for a P-P headphone amp too, since normal OP trannies of a suitable ratio seem rare.

[sorenj07]

What kind of VA should a toroid be for a given power in output wattage? Will a 50VA toroid be able to push 50W of audio? I'm guessing you want a fair bit of headroom for bandwidth/non-saturation purposes, right? I'd love to use a pair of toroids for some 6S19P's in push-pull..