Advice needed on power cables, wall warts, conditioning, electrical outlet

@alexberger Well, toroidal cores are harder to make and much harder to wind. Hence torroids are more expensive. For all I know, it may be prohibitive to shape exotic core materials into toroids.

Certainly my Lundahl silver phono SUT’s sound great, and they’re not toroids - but so do my VanderVeen designed ESL SUT’s sound great - and they are toroids. By the way, I did test my Quad 2905 ESL’s with a Plitron-made VdV toroidal SUT against a stock Quad 2905 with matched conventional transformers, in my own system, and it was just no contest for clarity and definition. Toroid triumphed within a few seconds.

As for tube amplifiers, I can think of no-one better to consult than Ralph Karsten of Atma-Sphere. I had some M60’s, and I’m pretty sure that they had toroids. Also, from a review of M60 Mk II posted on his website, "The two floating output-tube power supplies are fed by separate secondary windings of a massive toroidal transformer".

From the Mark Levinson site, "Unleash the full potential of your music as you go from the quietest lows to the loudest crescendo. The № 536’s toroidal transformer delivers massive power to your speakers".

So, in the realms under discussion, i.e. enough power to run an amplifier, two giants in the field seem to agree with me. Your thoughts?

Hi @terry9 ,

I think it is a function of power consumption.

Typical tube amp power consumption is 100-300 watt. So, for this parameters EI core transformer can be better. External electromagnetic field is less issue for smaller power transformers but a magnetic core quality can be better.

But for big power rating, toroidal transformers have more advantages.

FYI, Plitron is now Noratel:

https://www.plitron.com/home.html

Toroidal transformers are the worst for amplifier power supply.

IMO, nonsense. They contain the magnetic field more predictably, have a higher efficiency, lower weight, or, conversely deliver more power (better regulation). If well designed (key point!!!) there ought to be no difference. I use both and for each application there’s one that fits best.

If you have a lot of data, please present it - i’d love to learn. transformers, even according to practitioners, are partly dark art.

"@alexberger: Toroidal transformers are the worst for amplifier power supply."

The above is COMPLETELY UNTRUE. Toroidals are the BEST transformers for noise and efficiency.

Here is an isolation transformer you cannot beat. At 3000VA capacity and at 2.5% regulation, it can even drive a welding machine... quietly: