Questions for SUT users running vintage transformers -

[MisterDK]

Hey folks, wondering if you SUT users are hearing much difference in the brands of the transformers they’re built with. Assuming that your transformer gain and loading is close to correct for your cartridge and phono preamp, are you finding that some brands sound harsher or more metallic, some smoother, or some colored in some way? Also, are you noticing that they change (hopefully improving) after prolonged “burning in”?

Asking because, while I presently have two different SUT boxes with different brands of vintage transformers in them, each giving a similar gain option at one setting, one sounds decidedly better than the other. I haven’t let the worse one burn in for long though; it’s only got a few hours on it, compared to the nice sounding one with many hours. The nicer sounding, BTW, is using vintage Beyer Dynamic transformers. I have another one on the way with some vintage Newcomb TR-91’s in it and will compare after it gets here. Chances are that it’ll need some burn in time - or will it?
What brands of - affordable - vintage transformers are you finding sound the best to you?

 

[edwyun]

I do hear differences between different SUTs with the same turns ratio on modern units. I would expect the same for vintage ones as well.

 

[AvFan]

Asking because, while I presently have two different SUT boxes with different brands of vintage transformers in them, each giving a similar gain option at one setting, one sounds decidedly better than the other. I haven’t let the worse one burn in for long though; it’s only got a few hours on it, compared to the nice sounding one with many hours.

Part of the difference you hear could be that the less used SUT is magnetized to a certain degree. This thread discussed the affect of a magnetized SUT and how to fix it. https://www.audiokarma.org/forums/i...agnetaize-step-up-trans.843857/#post-12112967 The other part is I find transformers from different manufacturers sound different. My experience has been with Cinemag, Lundahl and Hashimoto SUTs.

 

[rothwellaudio]

One thing to bear in mind about many "vintage" transformers is that they were never designed to be used with moving coil cartridges, they were designed for microphones with a 200 ohm or 600 ohm source impedance. They can have far more turns of wire than they need for a moving coil cartridge, and that increases the resistance of the coils and the inter-winding capacitance. When used with a significantly lower source impedance (about 10 ohms is typical for a LOMC) the high frequency response exhibits a peak followed by a steep roll-off. The effects will be near the upper end of the audio spectrum or just beyond, depending on the individual transformer, and will be subtle enough not to be disastrous but possibly audible enough to make different transformers sound different.
I once wired-up a vintage transformer that a customer had bought off ebay. It had several primary and secondary windings and the customer wanted every possible combination to be available. I got the best performance I could out of it but it really wasn't anything special at all. Actually, some of the combinations were very poor. Anyway, the point is that just because a transformer is "vintage", doesn't mean it has any special qualities or is particularly well-suited to use with a low output moving coil cartridge.

 

[MisterDK]

Thanks, Mr. Rothwell. The reason I asked about the “vintage” transformers is because they can often be had cheaply and I thought that if I collect a few, some that may not sound as good with one cartridge could possibly sound good with another. Just playing around, really, and of course with my limited knowledge - I’m probably wasting some money.
Of the two I have right now, both were intended for microphone use, not MC phono cartridges. I think that one sounds quite good though with the AT cartridge I have set up, and the other is merely OK - but not great.
The one that doesn’t sound as good, was supposedly built up for a different cartridge (a LO Sumiko Blackbird), which I haven’t tried it with yet.

 

[rothwellaudio]

Thanks, Mr. Rothwell. The reason I asked about the “vintage” transformers is because they can often be had cheaply and I thought that if I collect a few, some that may not sound as good with one cartridge could possibly sound good with another.

If the transformers are cheap there's no harm in experimenting. As long as the turns ratio is in the right ballpark (1:10 is a good "general purpose" ratio which will suit a lot of cartridges) you'll get something usable, if not superb. Of course, measurements can reveal a lot, and without them you're guessing or hoping for the best.
Still, you can't do any harm and I encourage people to try DIY and experiment.