Toroidal vs EI type Power Supplies?

[Big Bean]

I was surprised when I discovered a large oldrer style EI type power supply in my Mccormack amp. Looks like Mccormack uses EI style transformers in ther whole line of stereo power amps. Apparently there is growing debate about the superiority of the popular toroidal core transformer over the conventional EI type for use in power amps. The Mccormack is no slouch in the power amp field so I'm real curious as why they seem to be marching to a different drum. Mccormack has not responded to my query. Any opinions on toroidal vs EI type power supplies.

Thanks,

BB

[djk]

A split-bobbin E&I type of at least 500VA will kick a toroid to the curb.

They are quieter (both mechanically and electrically), and handle overload much better. They cost more, and custom types are not available in small quantities at any kind of reasonable price.

[boom3]

Concur with what djk said. Also, a toroid is slightly less efficient than an EI style transformer and uses a greater length of wire for the same function. Toroids are self-shielded and for that reason many designers will accept a slight loss of efficiency. Cosmetically, the disk of a toroid looks more "high tech" than the rectangular solid of an EI transformer, whose outward appearence has not changed outwardly in about 80 years.

[Big Bean]

I found page. Interesting.

http://soundstage.com/maxdb/maxdb071998.htm

[krispykoilz]

Big Bean, here is some additional information for you. It is in two parts.

http://www.bryston.ca/newsletters/84_files/vol8is4.html

http://www.bryston.ca/newsletters/85_files/vol8is5.html

[Klipschguy]

That soundstage article was good. The Bryston article seemed a little agenda driven. I assume Bryston uses toroidal?

[jacksonbart]

good stuff - Thanks

[Big Bean]

Lots more good stuff here!

http:/soundstage.com/maxdb/maxdb.htm

BB []

[colterphoto1]

Is that why my THX amp hums so much? It has that type of power supply. I can hear the hum from 10 feet away with nothing playing.

[Big Bean]

Ten feet is a lot, I'm sure it was not designed that way. Does your THX system use a power amplifer with discrete power supplies for each channel ie FIVE transformers. I have a single large EI and I have never noticed hum but I can feel it vibrating when I touch it. Maybe a shelf or something is resonating the 60htz or check the screws on the core(s) themseves.

BB []

[Klipschguy]

Although I liked the little tranformer article, his crap about a wood block makes me a little uneasy about this guy. Am I wrong?

Read here: http://soundstage.com/maxdb/maxdb091998.htm

[Big Bean]

I can't hear that stuff. Maybe somebody else can.

BB []

[Gilbert]

I was surprised when I discovered a large oldrer style EI type power supply in my Mccormack amp. Looks like Mccormack uses EI style transformers in ther whole line of stereo power amps. Apparently there is growing debate about the superiority of the popular toroidal core transformer over the conventional EI type for use in power amps. The Mccormack is no slouch in the power amp field so I'm real curious as why they seem to be marching to a different drum. Mccormack has not responded to my query. Any opinions on toroidal vs EI type power supplies.

Thanks,

BB

my krell amps are loaded to the gills with several huge toroidal style xformers.

[Big Bean]

Krell is OK in spite of their massive power supplies and clean, viceral, gut twisting horsepower. Wana trade.

BB

[DrWho]

I was surprised when I discovered a large oldrer style EI type power supply in my Mccormack amp. Looks like Mccormack uses EI style transformers in ther whole line of stereo power amps. Apparently there is growing debate about the superiority of the popular toroidal core transformer over the conventional EI type for use in power amps. The Mccormack is no slouch in the power amp field so I'm real curious as why they seem to be marching to a different drum. Mccormack has not responded to my query. Any opinions on toroidal vs EI type power supplies.

Ultimately it comes down to the actualy implementation of the different designs. Each transformer has its own tradeoffs and there is different circuitry surrounding it to help minimize the negative effects.

In other words, it's more marketing than anything else. Will the best torrodial implementation beat the best EI type? I dunno - haven't heard the best of each kind []