Hello SY,

I have one First Watt F4 amp, so I’d be running it stereo unbalanced to drive my speakers.

Since the Impasse debuted, have you or others implemented any revisions that I should know about?

My speakers are at least 94db sensitive, my room is 16 ft x 14 and my ears can’t tolerate average SPLs much beyond ~ 60db-at least not much above the lower midrange band (i.e. allowing for the Fletcher-Munson effect). My midwoofers are cut off below 70Hz, where my pair of Rythmik 12" sealed powered subs take over.

Except for the subwoofers, my speaker system is a clone of Gary Dahl’s Azurahorn 425/Radian 745 Neo Be/GPA Altec 416 system.
https://www.diyaudio.com/forums/multi-way/100392-beyond-ariel-720.html

Are there certain tube suppliers of specific brands of 6SN7 tubes, or better sounding alternatives, that you would recommend for best performance with my speakers, such as https://www.sophiaelectric.com/ ?
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