Recommendations for MM Phono ~ Tube or Solid State

@lalitk I was use an Atma-Sphere MP-1. Its fully balanced; when using SUTs with it they ran balanced (as any transformer can) as well.

What if they are optimized for a specific cartridge along with rest of the components? And please don’t overlook or discount the user preferences.

@lalitk I probably have a skewed perspective as I have LPs that I recorded and I have the master tapes. So I know how those LPs are supposed to sound.

If the SUT is optimized for the cartridge and if its properly loaded it still will not have the bandwidth that you can get with an active phono section.

Years ago I found out how important bandwidth in this area can be; there was a phono section that came off as quite bright in a local dealer's showroom. They had us test it; what I found was the an extra timing constant had been added to the RIAA characteristic that caused it to go flat (so a 'zero' instead of a 'pole' for all you engineering types) at 50KHz. It caused phase shift down to about 5KHz. By removing it the phono section then sounded right, as well as measured right with the inverse RIAA network I used to test it; one of those cases where you could measure and hear what was going on.

I also "feel" that the 3160 is the first SS phono/linestage that ever made me forget I am listening to SS. Dare I say it’s very similar in SQ to my modified MP1 (which might upset Raul but which I mean as a compliment). I love them both. As you know, this is coming from a tube OTL guy.

@lewm One of these days you might want to hear what happens when you parallel more tube sections at the input of the MP-1 phono section, and then give the gain stages a better CCS circuit.

While I understand your preference for active high-gain phono stages and recognize the strengths you’ve highlighted, I believe it’s important to acknowledge that audio reproduction is highly subjective. SUT’s may not align with your experience of optimal sound, but they can offer unique qualities that others might prefer.

@lalitk Raul is right on this one. I hate to put it this way, but what you’re talking about has to do with what you’ve heard and also what you’ve not heard. SUTs, like active electronics, are not all the same. But if you hear an active phono section that has the gain and is really competent, its a pretty good bet you’ll change your thinking.

What is probably poorly understood in general is how wide the LP bandwidth really is. Its wider than analog tape even at 30 i.p.s. and wider than digital. Its also wider than most SUTs. Its not wider than a competent phono section. Bandwidth can be really audible due to a phenomena called phase shift, which occurs at the top and bottom limits of any audio device. If the device is passive, as in the case of an SUT, phase shift components can occur up to 10x the lower cutoff frequency or down 1/10th the upper cutoff frequency if the device rolls off on a 6dB/octave slope.

The ear converts phase shift over a range of frequencies to a tonality. So subjectively you hear the limits of an SUT as a lack of bass (even if its flat to 20Hz) and a bit of a darkness in the highs. This is of course highly variable with each SUT! Something to keep in mind with SUTs is that they are transformers, and so transform impedance. What this means is that if you change the cartridge, the correct load to prevent the transformer from ringing (distorting) changes too. BTW if the SUT is ringing, it will sound brighter despite not having much bandwidth past 20KHz.

Its that last bit that means that a lot of SUT setups are not optimized!

In fact, the bipolar transistor that Raul et al use in the MC gain stage is out of production and was not replaced by anything as good or better for the purpose, probably because transistor evolution is not motivated by the design and build of phono stages.

@lewm to be clear, Raul had nothing to do with the engineering.

IMO, the one thing that SUTs bring to the table is immunity to the RFI that LOMC cartridges otherwise generate. SUTs simply don't have the bandwidth so they block the RFI. If your phono section has troubles with RFI being injected directly into its inputs (and many do, judging by all the phono sections out there with 'cartridge loading' switches on their front panels) The SUT seems really nice.

But I've found that if the phono section is immune to the RFI and otherwise has the gain needed, it will simply be more transparent. Transformers inherently introduce distortion and bandwidth limitations, usually having less bandwidth than the LP itself.