I own the amps (monos). Replaced Spectral DMC 30SS -Series II, and never looked back. Phenomenal amps. Two caveats - they did not work well for me with the Spectral preamp (I now play sans preamp, will try tubes at some point), and MIT cabling sucked (back to transparent reference).
Excessive feedback is bad. I do not know if 40db exceeds some magic audiophile number. The book is still unwritten as to whether it is audible negatively in this amp.
I think more important is Paul's admission that he could not get this level from solid state or class D. He hates tubes so much he hid them in the back.
Excessive feedback is bad. I do not know if 40db exceeds some magic audiophile number. The book is still unwritten as to whether it is audible negatively in this amp.
I think more important is Paul's admission that he could not get this level from solid state or class D. He hates tubes so much he hid them in the back.
The problem is to define "excessive". Like most things, just a flat statement of how many dB is insufficient. Loop order, open-loop parameters, bandwidth, circuit topology and type of feedback, a myriad of factors determine how feedback impacts the output.
So, at the risk of showing my audio ignorance I'm making a confession.....
I've nodded knowing every time I've heard his name, he is one of the greats after all.
I've nodded knowingly but I've lied it. Truth is, before the hype around this amp I had *never* heard of Bascom H King.
I'm blissfully ignorant of both big name designers and design principles. I can tell when I have a very reasonably priced phenomenally sounding amp in my system though.
I think more important is Paul's admission that he could not get this level from solid state or class D. He hates tubes so much he hid them in the back.
Actually, the tubes are in the input stage, so putting them in back makes a lot of sense. Shortest path from input jacks to first gain stage, reduces susceptibility to noise coupling, and all that jazz. I have long held the opinion that tubes make most sense at the input of the power amp where they can impart that tube "character" without sacrificing output impedance.