Step Up Transformers….Are they Worth the Trouble?

rauliruegas

... AR, VAC and MAC use SUTs ( passive not active designs. ) ...

You're mistaken. There's no SUT in my ARC Ref Phono 2SE. It uses an FET on the MC input. I'm pretty sure this is common on ARC phono preamps.

You’re mistaken. There’s no SUT in my ARC Ref Phono 2SE. It uses an FET on the MC input. I’m pretty sure this is common on ARC phono preamps.

@cleeds Correct - at least modern (and relatively recent) ARC Reference phono stages use a JFET based MC gain stage (voltage mode). I had a Reference 3SE. Its MC mode (called High Gain) sounded very good, but I still preferred a SUT - the MC mode is simply "leaner" sounding. I like a slightly fat, lush sound - and I don’t need to hear for the 1,000th time how this is wrong. The SUT was *easily* quieter, too. Fremer mentioned some susceptibility to EMI / RFI noise in its MC mode. I heard this very easily with a plasma TV in the next room. Sounded like demonic garble noises with the TV on - and went away when off. Also found its inherent noise floor would start to make itself "known" with cartridges below 0.3mV. Again, SUT’s had a distinct advantage here. I do listen loud - audiophiles who keep their levels below 85dB may not notice these issues as readily. That said, once you add groove noise, it’s debatable how much this actually matters.

The Ref 3SE’s Low Gain mode is still probably the best MM stage I’ve heard. Really, really good with a SUT. I’ve always liked the 6N30 tube, in line stages too. It is very linear and clean; not as fat and lush as other tubes. That’s right! I’m allowed to like "fat" sound in some cases and "cleaner" sound in others. It’s all just preferences when we hear the end product anyways. 6N30 just strikes the right sonic balance between traditional tubes and SS for me. 

Mijostyn, I am curious what you mean when you use the phrase "match by a few ohms", where you applied the term to SUTs.

As to tubes vs SS, I think you would have trouble supporting the notion that the best tube phono stages are categorically less expensive than the best SS phono stages. For example, the Ypsilon VPS 100 costs $30K and only develops 39db of gain. VAC make some high end units, too, and there are others I don’t know about. I know that Channel D make a $90K SS phono that does both current and voltage gain, and I don’t know how much some of the stratospherically expensive SS stages, like Soulution (sp?) and others cost. (Has anyone heard any of those?) I think Raul mentioned someone brought the top of the line Channel D unit to his home, and they compared it to his 3180 Phonolinepreamp; results in his group of listeners favored the latter unit, and I believe it because the 3160 is the best sounding SS phono stage I have ever heard in my home environment. Which is to say it’s the only one I have auditioned that I could live with (and am living with) long term, among those I have heard. I’m a tube guy at heart but with some qualifications, like OTLs only, for amplification and a preference for tube/SS hybrid phono stages to achieve high phono gain. This is a bit different from the ARC approach (and which is used by a myriad of other manufacturers) of using a FET to add gain at the front end; I prefer a hybrid cascode input for high gain. On the low end, the market is replete with inexpensive SS phono stages (less than $500) that people swear by and which typically offer high gain. Op amps make it easy and cheap to do. But could we (you and I) live with any of those? The only tube phono in that low price range I can think of is the Bellari, and it’s MM only. Anyway, I have avoided SUTs for 45 years so far, but I never would say not to take that route. I am sure it can work beautifully. (Which is also what you said.)

A very very brief visit

The SUT in the link might be of interest, a decent pricing for the features on board.

https://www.nixiekits.eu/product.php?key=mc_to_mm

@cleeds : AR, yes you are rigth because is not a tube but and hybrid one. My mistake.

R.