SUT Advice - Which Ones Are The Best?


I am currently in research mode.  I want to add a SUT to my set-up but I am finding that there is not a lot of information from my local audio shop resources.  It seems that SUTs are outliers in the high end audio world.  
That said, I have read several articles in magazines and the web touting their merits.
Of all the brands out there I am most familiar with Bob's Devices.  Art Dudley wrote many good things about his experiences with Bob's SUTs, and I happen to trust Art (God rest his soul), but I'm wondering if there are others I should consider as well.  Please post your recommendations if you have experience with any SUTs, regardless of brand.
As for my set-up, I have a SME 20/2 turntable, Tri-Planer tone arm, Lyra Kleos cartridge, and KTE LCR Mk5 Phono preamp.  I do not know if I will always use a Kleos cartridge but I do think I will always buy low output MC carts.  I hope to buy something that will work with low output MCs but have some adjustability just in case.
I'd love to hear your recommendations.
Thanks!
Peter
128x128snackeyp
@rauliruegas,

On this one I respectfully disagree:

I run a Zyx Universe through a Zyx Artisan stage. When inserting an Altec TBB-103 based SUT that Bob made it gives a substantial leap in performance: faster, more soundstage and definition of instruments. Ruling out SUTs as a way of improving vinyl playback contradicts what many cartridge designers are saying.
There is no way that your Kleos can in any way sounds with better quality level through a SUT in your system when you own a very good phono preamp that handled any LOMC cartridge.

When you add a SUT to your specific system you are adding an additional stage with severe limitations in frequency range against your KTE unit and other issues down there but additional you need to use an IC cable with additional connectors at both ends of the cable from where the cartridge signal must travel through and in all that " travel " the signal is degrading and developing additional ( every kind. ) distortions: you are contaminating that beloved MUSIC signal.
Well, since I’m in the middle of refining a MC/MM (jumper it to your liking) RIAA gain stage design I’ll bite. You think a gain stage, amplifying a 0.05-0.5mV signal by another 10-20X has no distortion? Do you realize how lower the power supply noise must be? Or how high the PSRR must be to make that irrelevant (which takes some doing)?

I will take two wires and a rally, really good transformer any day. Now you may ask "so why are you designing a low noise gain stage?" - answer: simplicity and cost. A good SUT (hate that acronym) is quite costly and heavy and somewhat complicated for many reasons that are peppered throughout this discussion.

I’m no necessarily arguing for a SUT, but i’m also not convinced that the active stage is a no brainer. Mitch Cotter agreed, and he was no mathematical slouch.
G


I think in a perfect world @rauliruegas is correct...the goal is to simplify the signal path and not add a SUT if at all possible. The problem is that unless you're using a top-tier SUT there is a good chance that a quality SUT combined with the MM-stage may outperform the onboard MC stage.  I have seen this in many of my phono stages but I've never owned a truly high-end phono.  A/B comparisons in my gear history shows improvements to SQ when using a SUT.
Not to be difficult, but to get everyone on board with the simple facts rather than vague goals of "simple signal path": 


how does replacing many active components with one passive component, that in fact performs an impedance transformation rather than delivering pure voltage again, "simplify" the signal path???  In my view it vastly complicates it.

if you think an MC RIAA stage is a single stage, you are generally mistaken. It's a bunch of gain stages -and from MC to line in, typically three, with each having multiple active devices. Both the aggregate gain and number of stages can be reduced by placing the RIAA filters in the feedback loop of quite a hgih gain and complex stage, but now we have introduced a complex, global feedback loop which i personally find undesireable.


vs ONE passive device.  yea, it has complications too, but its much simpler.