Posted by Lew on October 28, 2003 at 14:25:59:
In Reply to: Biased opinions and improvements posted by Roy on October 28, 2003 at 13:51:35:
This one may fall in with Matt's lament that none of us has stepped up to tell him how to
build a direct-drive amplifier. It's simply a fact that none of us regular SLOGers is really up
to either task, as far as I know. If I am incorrect in this assumption, by all means let
someone step up to the plate. Mark Gilmore would probably have insight into how
automating the bias supply might be done, if he were contacted directly. Martin-Logan is
another ESL company that uses the "bias on demand" approach. They are very secretive as a
rule, but perhaps one of us can find out how they accomplish the trick. I am not sure that
such circuits are "transparent" to the audio signal, however, and I would like to know that
the one I would install in my speakers would not create more problems than it solves. Like
you, I have taken a very conservative approach to bias adjustment in recent months. I just
leave it at a level where I don't hear the crackle at all and never touch it.