Output transformer listening impressions?

[Evenharmonics]

I’ve looked through some of the threads here on different output transformers which cover measurements and prices. What do you say we share some listening impressions?

I recently switched from Hammond 1627SEA 2.5K Ohm primary, 160 mA, 30 Watts to Electra-print 3K Ohm primary, 100 mA, 15Watt for my Tubelab SE amp which uses 300B OP tubes. It may not be apple to apple comparison due to different numbers but the impressions between them are as follows.

- Ep (Electra-print) has better imaging between instruments and vocals than Hammond.
- Ep produces little better controlled mid and high (if this is a proper term) and sounded smoother.

It’s only been a week so that’s what I have so far.

Those who switched output transformers, what was it like?

[lochness]

I've used a lot of the "Cheap" transformers (Hammond, edcor, no-name stuff I found on ebay, etc...) and I've had a chance to listen to some expensive transformers. Honestly maybe its because of the music I like but I prefer the cheap transformers (especially the edcor ones). Hammond tends to sound a little muddy like a lot of old consumer tube audio stuff. Edcor tends to have a very clean and tight sound but can be harsh. The cheap no-name stuff on ebay ranges from the terrible to the musical.
I've personally never been impressed by expensive transformers. Any pros to them don't warrant the cost.

[Evenharmonics]

Originally posted by lochness
maybe its because of the music I like

What kind is it?

I used mostly jazz to compare mine.

[lochness]

Mostly grunge, hard rock, and symphonic metal. I use a Nightwish album when I test amps...the singer is sooooo hot...yah I'm a geek...

[dsavitsk]

Originally posted by lochness
the singer is sooooo hot

How do you hear that through the transformers?

Fwiw, I tried several single feed transformers in the same amp -- Edcor, James, E-P. The Edcors were indeed fine, better than fine. Quite good in fact. But, the James were better, and the E-Ps were better still. Worth the money in my opinion.

In smaller transformers (line level) I have had very good luck with Magnequest (nickel), Lundahl (mu-metal), Lundahl (amorphous), Cinemag, Jensen, Intact (nickel), and Silk (amorphous). All are a little different, but all were head and shoulders above the smaller Edcor and Hammond that I tried.

[7n7is]

Back when I was young and had more ambition, I wound two output transformers myself using I's and E's (laminations) from two power transformers. I used some articles as a guide and interleaved the primary and secondary windings a couple times, made screen taps and used high quality vinyl electrical tape for insulation. The sound quality was very smooth and had high resolution. I wondered if using vinyl tape or similar insulation (maybe teflon tape) works better than paper insulation that's typically used in transformers. Some transformers are potted, too, maybe to reduce vibration of the windings?

[lochness]

How do you hear that through the transformers?

The finnish accent and the sexy voice...not to mention I've seen them in concert.

[richwalters]

Originally posted by 7n7is
I wondered if using vinyl tape or similar insulation (maybe teflon tape) works better than paper insulation that's typically used in transformers. Some transformers are potted, too, maybe to reduce vibration of the windings?

Interesting but treated paper or (Fullers 60u paper) is still the preferred insulating medium for quality audio transformers. The yellow insulating tape which self algamates after a curing period, used by many commercial transformer manufacturers (to reduce impregation time) has one of the worst dielectric constants, i.e emposes an increased self capacitance between windings, a disadvantage for audio transformers. There are various low hazardous dielectric varnishes around but at considerable expense.

Like so many classic materials classed as toxic, those were often the best for a particular application. That applies from lead paint to BHPhenols previously used in capacitor and transformers.

richj

richj