Step Up transformer

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.

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.

Very interesting! Would the Grail have enough gain at 3 - 4 ohms to counteract the reduced ~ 0.06mV output at that point? And how does one calculate gain from a transimpedance stage - is it directly related to the source impedance? And probably also depends on real input impedance (not 0) of the stage.

this is one of those ideas that works really well In the simulated world where an ideal  2:1 stepdown nets a 2X increase in output voltage.  Real world reality of greater than 0 input Z of the current stage and DCR's of the windings makes the actual measured gain from a stepdown feeding a current stage a fair bit less than expected.  I did net about a 3dB increase in output from my one go at this with a 4:1 but the current stage was less than ideal.   I ended up going for a 1:1 at the input of the current amp since the possibility of DC offset from the complimentary Jfets I was using is a very real problem.

dave