My cathode follower McIntosh Mx-110 drive 25’ rca w easy in a moderate RFI environment- suggest you try that. While I don’t have Herron preamp, I have his phono - excellent gear. A low capacitance Blue Jean cable built on Belden wire should allow you to test a 15’ run for about $75
if I was in Seattle I would loan you mine
best
jim
if I was in Seattle I would loan you mine
best
jim