03-06-12: Doggiehowser: Didn't Nelson Pass create the sliding bias thingamabob? :03-06-12: Doggiehowser
In actual fact my ex boss (Steven Deratz) invented the first sliding bias system back in 1978 and had a world wide provisional patent on it for a couple of years. But his system worked a bit like negative feedback, it monitored the signal and tried to adjust the bias up and down in real time which was a loosing battle because it was never in real time, just like global negative feedback.
I don't think Nelson ever had an auto bias system just an optical bias system which was on the S300/S500 MkII's, when he did Class A he went more for the real thing.
Later Krells plateau bias where it kick it up and stays for a while and gradually comes down is the next best. But think about it the initial (first) transient is not in class A because it lags behind like my ex boss's system (so it's class B "harsh") then if successive transients "lower" than the original follow all's good they are in class A, if higher they are in class B again, and if there is a quite passage the bias drops down again and it starts all over again.
This is why, I strongly believe that proper hard biased Class A cannot be by any auto adjustable type system.
Cheers George