Merc, your farther down the garden path than me. Logic tells me that those with hissy 950’s already cover such a broad range of setups: speaker brand/sensitivity, interconnects, amps etc. If you don’t have the hiss it’s not there! Another point, (one of your test units had it / the others did not).
WHA DA ya think?

Ouch, ouch, ouch Minuteman! What brand of rolling papers did you use?