Posted by Lew on February 12, 2003 at 07:19:14:
Ever since you guys made me afraid to allow my speakers to "crackle" a bit on a steady-state basis, I have been adjusting the bias downward to eliminate any audible noises. I say this as if it were a continuous process, because it is: the M1s constitute a huge capacitor and it takes a while to bleed off voltage after one reduces the bias, so I cut back a little bit each day until the sizzle became inaudible. This worked fine for one of my two speakers. However, I find that for the other speaker the crackle or sizzle tends to return in about 24 hours (or at my next listening session) for each new lower setting of the bias pot. In other words, for that speaker, I have been cranking down the bias in tiny increments, but the result has been virtually no effect on the audibility of the crackling, after I wait about 24 hours. (When I listen immediately after cutting back on the bias, the crackling does seem to have gone away or become less audible, but it comes back a day later at the new lower setting.) Has anyone had a similar experience? This smells like I have a bad or malfunctioning bias pot.