Ptss - yes, I looked into the Equitech product line a while back while researching the benefits of various power conditioning approaches and read most of the web site info back then.
Scaling up a transformer design to the power levels at which their products operate, significantly increases the mechanical noise factor and the footprint. So for their products, toroids are an excellent choice.
Even though some electrical efficiencies are also achieved, I believe noise and size are the main issues that are easily overcome by the use of toroids.
It’s not so much that one design is clearly better than another, but more of a choice as to what the designer is "prepared to live with" and what steps they are prepared to take to address the shortcomings of a particular transformer type
Except - in those rare cases where the designer pulls out all the stops and designs the transformer of their choice to provide the very best performance.
Two companies that I believe excels in power supply design are...
- NAIM - mostly use toroids for their power supplies
- Macintosh - mostly use EI for their power supplies (or used to)
Also, there are still some "uses" where EI has been the preferred type for a very long time, such as amplifier output transformers.
From what I have read, it appears that where the entire audible frequency range must be handled, as opposed to the 50-60 hz of the mains supply, EI appears to be better suited. But that may be changing as toroid (and other designs) progress.
Personally - I do not allow the minor differences between the various types to sway me.
My approach - If a component sounds exceptional, then the designer has achieved their goal - regardless of transformer type.
With the "quality" of component I now find myself purchasing, I have to believe the designer has already obsessed enough over their selection - that’s good enough for me :-)
From a DIY
Regards.
