FS: superb three-ratio implementation of UTC A12 step-up transformer

[montesquieu]

Really hesitant to sell this but the gap between what I got for the EAR 912 and the phono stage I have my eye on is substantial and I need to try and fill it.

For sale - the phono step-up transformer assembly that was made for me by Andrew Rothwell some time ago, using US-made UTC A12 transformers. There are cult objects in demand even over their Altec counterparts.

There are literally dozens of ways these can be wired between their primary and secondary coils, in series and in parallel, to deliver all sorts of results, but Andrew got out his slide rule and his oscilloscope to work out both theoretically (by ratio) and by measurement (to optimise the quality of the signal) the ideal way to wire them as a multi-option step-up. He then executed them superbly in a unit that gives 1:12, 1:20 and 1:33 step-up, covering the bases for the vast majority of cartridges out there from 40 ohm Denon 103 to 2-6 ohm SPUs.

The unit also has a bypass switch to enable it to be taken out of the loop if a MM cartridge is fitted.

All up, with the purchase of the A12s from the US, postage and tax, and Andrew’s time, effort and materials to do a custom job on these, I’m out a couple of hundred more than the £450 (including RMSD) I’m looking for for the unit. But I think that’s a fair price for a truly superb SUT that also (in my option anyway) also looks super cool.

There was a thread on this a while back - since then I’ve used it with a Technics SL10 / Technics EPC310 moving coil cartridge in the study, and in the main rig with my Miyajimas and with a vintage 1960s Alnico SPU. It matched wonderfully with the SPU. https://theartofsound.net/forum/show...up-transformer Like all SUTs it repays careful placement, it worked silently after some trial and error in both my study and my main rig.

[montesquieu]

Some more info on this as requested:

The 1:12 input equates broadly speaking to an SUT that in Japanese SUT land would be labelled 40 ohm and is ideal for the Denon 103, some Benz models, certain Dynavectors and other highish impedance cartridges. The 40 ohms referred to is the coil impedance of the cartridge, not the SUT impedance.

The 1:20 input equates broadly speaking to an SUT input that you might see labelled as 12-15 ohm and is ideal for a very large number of cartridges of fairly standard impedance of 10-20 ohm such as pretty much all of the AT stereo cartridges, and many many others. This is what I use with my Miyajima which is 15 ohm at the cartridge coil.

The 1:33 input is for low impedance cartridges broadly in the range 2-7 ohms such as most Ortofon low output MC cartridges including Cadenza/Kontrapunkt series and all SPUs, Koetsu, Lyra, Ikeda, Fidelity Research, ZXY, Transfiguration and many others.

As with everything SUT-related, there's a subjective element and you might prefer a cartridge run at the setting next to the suggested one above.

This really is a very flexible phono step-up.

[WESTLOWER]

Super SUT, I’ve had the pleasure of listening to this. Very good quality.
Glws

[lordmortlock]

Seconded.

There’s a wonderful fluidity about the sound with this unit in the chain. If it had a Shindo or Miyajima badge on it would cost three times the amount Toms asking and I’m not sure it would sound any better.

[montesquieu]

This is now withdrawn I was looking for a quick and easy sale but it’s proved to be more hassle than it’s worth.

[mikeyb]

Just a couple of months too late for me, bought Jimbo's K&K, I'm sure this would be superior but I've really gone way way over what I had intended to spend on HiFi and with three trips abroad to fund this year I'm trying to be good

I've seen so much kit I lusted after come up for sale AFTER I've bought something else in the last year or so, just need to look at the number of valve amps that have been for sale recently and when I was after one there were virtually none.

C'est La Vie

Do you take monthly payments?

PS: can't remember but was this one of the ones you loaned to me a while back?

[WESTLOWER]

This is now withdrawn I was looking for a quick and easy sale but it’s proved to be more hassle than it’s worth.

Oh dear! Sorry to hear that

[montesquieu]

Oh dear! Sorry to hear that

oops ... it was the CDP I decided to withdraw.

this is STILL AVAILABLE

can't remember but was this one of the ones you loaned to me a while back?

yes it was.

[mikeyb]

oops ... it was the CDP I decided to withdraw.

this is STILL AVAILABLE



yes it was.

Thanks, can't remember if it suited my setup or not.

[montesquieu]

Thanks, can't remember if it suited my setup or not.

Looking back you said that it took away the edginess issues you were having with a particular cartridge but in the end you decided to sell the phono stage and try something else.