Step Up transformer

" I’ll never need to upgrade. "

If it's a different presentation you're curious about, then a vacuum  tube unit is what must hear in your setup.

The "better" models seem to sound more "organic" than an equivalent SS unit-IMO.

I’ve been wondering the same thing, whether to try a quality SUT.  My carts are Lyra Etna, VDH Van Cru, Aida Mammoth Gold, Koetsu Rosewood Sig Plat, Koetsu Coralstone D.  I have the VDH Grail SB transimpedence (current) phono stage to drop the noise floor, not sure if I have to purchase another phono stage (voltage) in order to try a SUT. I was thinking starting with a Koetsu SUT for my Koetsus. 

Yes, you definitely would need a conventional voltage driven phono with MM capability in order to insert a SUT into your system. But the VdH Grail is reputed to be superb, so I don’t know why you’d even consider it. On the other hand, I personally have never heard the Grail or your system.

I have the VDH Grail SB transimpedence (current) phono stage to drop the noise floor, not sure if I have to purchase another phono stage (voltage) in order to try a SUT.

a SUT will not work with the grail.  Of morbid curiosity, a step down transformer will work and in theory give you more output when feeding transimpedance stages.  Want to try a 40Ω denon 103 with your current stage?  Run it into a 4:1 step down transformer and you net 4X the current and a 3-4Ω  source impedance.

dave

Cool idea!

But I don’t think the Grail lacks sufficient gain for the cartridges listed. The motivation toward a SUT appears to be purely to enhance SQ. Although mating a 40 ohm cartridge to the Grail may be a source of dissatisfaction to begin with.