SO ebay is completely off the rails on all things stax.
I see what looked to be a standard bias SRD-7 for $259. Seller claimed
it supported pro bias cans. I messaged him to see if it was modified.
Answer:no. So another BS claim by a seller. You can plug it in and use it,
but it certainly isn't pro bias. It will sit on the bay for the next month like
hundreds of other overpriced stax crap, most of it "untested".
No wonder multiple miracle stax energizers are popping up from
shady start up companies.