torroidal trannies question

[old_picker]

i seen a bunch of these in an electronics place the other day and also seen them being used in amps

what difference is there as opposed to using a standard laminated type PT??
price? tone? convenience?

[Robert M. Martinelli]

Well, the answer has multiple faces.....
conventional trannies are cheaper to manufacture ( they need standard winders ) but they have a lower efficiency, because some of the flux gets lost, also, they' re noisier, because this lost flux gets around, therefore hum is likely to be picked up by the surrounding components.

Toroidal trannies are more costly to manufacture ( try to wind one by hand, and imagine the movements the winder has to make ); they are more efficient ( no flux lost in the iron, the losses come only from the copper wire ), so, all the other factors being the same, they also save some power....As to the sound, they tend to be quieter, and they could improve the low end response because they can supply higher currents with lesser heating ( and losses ) and, used in "tandem" with big enough filter caps ( and of course silicon rectifiers ) they could widen the dynamic range IMHO.
Hope this helps
Best regards
Bob

[Steve Conner]

Toroids make great PTs because they weigh about half as much as an E-I tranny of the same VA rating.

As OTs they're not so hot, because they have poor tolerance of DC from mismatched power tubes, and they saturate pretty hard, so you don't get the fattening up of the bass that you get from an E-I core made of some old 60s grade of iron. You have to choose between clean bass and nasty sounding distortion.

(I've measured this in the lab, but I have no proof of the audible effect yet.)

[Enzo]

They often are less tall as well, so you can fit your power amp into a two-space rack chassis instead of a three-space.

[Old Tele man]

...one benefit is toroidal Output Transformers have transfer efficiencies approaching 100%, being typically in the range of 95-98% efficiency!

...they're "very" efficient at a single frequency, so really 'shine' as Power Transformers which operate at only 50Hz or 60Hz.