SUT - electrical theory and practical experience

Your statement means that you like sound full of developed COLORATIONS/DISTORTIONS.

@rauliruegas  - and I'm OK with that 😁
I'm definitely not trying to pose as someone in pursuit of the "ultimate truth" in sound. I go for what pleases me the most. 

@billstevenson 

I definitely share your philosophy! It's analog. It's meant to be beautiful, not "perfect".

I’m a SUT + LOMC fan. I just like the sound many (most?) SUT’s provide - rich, meaty, weighty. In my system, that’s the right direction - other systems may differ. I have an Audio Research Reference 3SE with a really great JFET MC stage. In the past I’ve had a Herron VTPH-2A, also with a great JFET MC stage. These JFET stages sound great, BUT they’re inevitably leaner and more sterile sounding than the SUTs I like. I have about a dozen MCs, so my listening experience is not limited to 1 or 2 models.

That said, there’s a pretty great variance in the sonics of different SUT brands. The difference can be as significant as changing cartridge brands, even when the step-up ratio is kept close. It’s quite striking. The blue-label CineMags (this includes Bob’s Devices Sky, 1131, 1254) are very much on the rich/lush/weighty side of things. The EAR has a particularly romantic tube-like midrange. The Quadratic MC-1 (a CineMag blue but with a MUCH bigger core than usual) has extremely low distortion through the midrange and treble with extremely powerful bass response. The Hashimoto and Koetsu are also excellent, and a bit more neutral, though still with more weight than a JFET. The Lundahl LL1931 and LL1931Ag (amorphous core) is much thinner and more "crystalline" sounding - not a bad sounding SUT, but not my personal preference! I think I actually prefer the JFET stages to these. Also - don’t skimp with a cheap SUT; I found the Red-label CineMag 3440A (cheaper than and blue-label) to be borderline bad, and the Lundhal LL9206 (cheaper than LL1931) to be fairly mediocre.

One practical consideration is you really need a very short, low capacitance run of cable from SUT to phono stage. If not, you’re going to REALLY hear this cable, in a bad way. And a 20x step-up ratio is usually a "pretty good" choice for many/most LOMC cartridges.

I’ve found a good SUT will be quieter than a good JFET stage IF (!!) you can properly address all grounding gremlins.

"One practical consideration is you really need a very short, low capacitance run of cable from SUT to phono stage." Which is a good reason for having a high quality SUT built in to the phono circuit, on board.

@lewm - That’s somewhat true. It’s an advantage to be onboard in the phono stage box. However, I have LL1931 built into my VAC Renaissance SE (another phono stage I own) and my preference for different SUTs greatly overrides the advantages of being onboard. I also have an outboard K&K SUT box with LL1931Ag (i.e. I’ve tried LL1931 both onboard and outboard), so I know it’s really the LL1931 sound that I don’t like.

Being onboard reduces the chances you’ll have a grounding hum issue. And of course it eliminates the chore of picking a transparent IC. But once you know you need a low capacitance short run IC, it’s pretty easy to find a "transparent enough" cable.

For me, the ability to choose a SUT to my preference is by far the dominant factor over issues with IC’s or grounding. I’ve yet to be super-impressed with an onboard SUT.

In practice my SUT experience was disappointing. I used highly regarded Cinemag transformers with my Lyra Delos cartridge perfectly matched. The sound was energetic and loud but the treble was edgy and grainy.

Using my Sutherland 20/20 fully active without the SUT sounded much better.

SUTS are something you add if you do not want to purchase a good active phono preamp. My experience.

I don’t doubt your experience. But I’m simply curious as to which "highly regarded" CineMag you tried? Quite frankly I found their 3440A (possibly their most common SUT) to be bad. I hope yours was at least a blue-label (better laminations) model other than the 3440 - they are MUCH better imo.

Every system & ear is different. Most will regard the MC stages of Herron VTPH-2A and Audio Research Reference 3SE to be at least "good", but in my system they both lose out to a well-selected SUT - for multiple MC cartridge brands & makes which I have in my collection. But you have to pick the "right" one! That goes for active MC stages, too. 

Dear @mulveling : SutherlaND 20/20 mk2 IS A VERY GOOD ss PHONO STAGE DESIGN ( LIKE THE pS aUDIO sTELLAR. ) AN YES BEEN an active high gain design just outperforms I think almost any SUT.

@rauliruegas Hi Raul,

I’m sure the Sutherland is a lovely MC stage. I get that it’s an active trans-impedance amplifier, different from my JFET MC stages or SUTs. At this point of my journey, I have no interest reading published reviews of gear.

What I’m not quite sure of is your angle here. Please let me know which of the following apply (check all that apply lol):

• The JFET MC stages in the Herron VTPH-2A and my ARC Ref 3SE are not "good". If you recall, I prefer selected SUTs over both of these. (I’ve also had other JFET MC stages too, but these two are generally lauded as very good if not exceptional)
• More generally, both voltage amplifiers and SUTs are not "good". Trans-impedance is the way
• It’s actually my system and/or hearing that is not good :)

@mulveling 

The SUT I used include Cinemag 1254 transformers wired at 1:10 for my Lyra Delos.  

It sounded louder because of the extra resulting gain and really good but ultimately not as refined overall as my Sutherland fully active.  

Thanks. There are better SUTs (for more money), but the 1254 is indeed a good one. I was afraid you were using a 3440 but that's not the case. A good mark for the Sutherland, indeed. I'll have to try one someday!

Btw, @intactaudio  : you capacitance parameter of 80pf coukld be not real to make SUT measurements as the 300k load.

Normally what sees the MM stage + SUT is a load of 47k and capacitance around 200pf. Then measures arwe different that with your " choosed " parameters.

Unfortuntaelly cable manafucterer almost never gives the cable capacitance but almost all are higher than 150pf and even over 200pf.

I think everyone who prominently recommends SUTs on this forum also cautions to select low-capacitance cables. There are ample phono-targeted ICs optimized for low capacitance. Select one of those models, keep the run short (ideally under 1m), and hitting a capacitance under 80 pF is quite easy.