SUT experience

I have the VDH Grail SB “current” phono preamp, so trying out a SUT would require an “voltage” phono preamp.  I have a few Ortofon SPUs and 2 Koetsu carts- was wondering if I should try SUTs - what’s the sonic benefit?  

There is no real sound benefit from a SUT, a Phonostage is very very capable of presenting a recording in a away that is satisfying for numerous listeners.

A SUT 'will' add a Richness in Tone to a replay when used as a comparison to a typical MC Stage.

SUT's are generic in their voicing, the Rich Tone being perceived can be scaled from a Hint of Richness ( a tight fast decaying Bass Note is maintained, maybe a little underpinned with weight) through to a Very Noticeable ( very loose Bass Notes with a extended presence, possibly, depending on the individual listener, this Bass Type treks toward the point of being overbearing).

A Head Amp of the designs I have heard in comparison to a SUT, can be described as being leaner in the voicing than the leanest SUT types. A Head Amp can be more in liking to a MC Stage.

To date, as a personal experience, I have not discovered a Phonostage that has been encouraging enough, to not use the options for voicing a Cart's produced sound via a SUT or Head Amp.      

A “head amp” or “pre-preamp” is simply a linear active gain stage to boost the cartridge output so the ensemble can then drive an MM stage. If you start with a high gain MC phono stage, there’s no role for a head amp. And a head amp, like a SUT, requires the insertion of additional connectors and cables in the signal path.

Correction Required

My statement should have been,  " SUT's are not generic in their voicing, "

Welcome to the SUT experience! IMO a good SUT sounds like "music" and further differentiates vinyl’s sound away from digital.

There are many different SUTs, each with their own distinct sonic character. Choosing the right ratio for a given cartridge is extremely important - much more than loading considerations. SUTs with 2 or more taps are very handy. My general-purpose favorite SUT is the EAR (MC-3 and MC-4; 3 and 4 taps respectively).

There is perhaps even more variance in the sound of various MC pre-preamp stages/SUTs that there is with RIAA MM stage - though the latter is crucially important as well.

JFET (voltage) pre-preamps can also be excellent in the right setup. But most of them tend to sound more "sterile" than SUTs. I like Jim Hagerman’s various Piccolos because they sound good and are cheap, at the expense of a bit higher noise floor (not problematic IMO). Most are JFET (voltage) based but he just added a Piccolo Zero model that is trans-impedance (current) based. I have one on order to try :)