I have been tasked with the repair of one of these lummoxes.
Principal symptom - gradual loss of positive going swing on L channel as
it heated up. Found that some of swing returned if I cooled the + side predriver
(MPSA92) so I replaced it, and the adjacent current sources (BC556x2) This
helped a lot but when I gave L and R a good roasting, found the same fault
appearing on the R channel. Transistor replacement did not help. I'm beginning
to suspect some deeper systematic issue. Audiolab could(would?) not help and
referred me to a service dept in Germany (I'm in New Zealand!). Does anyone
know of any "known issues" with these amps?.
Cheers, M.
Principal symptom - gradual loss of positive going swing on L channel as
it heated up. Found that some of swing returned if I cooled the + side predriver
(MPSA92) so I replaced it, and the adjacent current sources (BC556x2) This
helped a lot but when I gave L and R a good roasting, found the same fault
appearing on the R channel. Transistor replacement did not help. I'm beginning
to suspect some deeper systematic issue. Audiolab could(would?) not help and
referred me to a service dept in Germany (I'm in New Zealand!). Does anyone
know of any "known issues" with these amps?.
Cheers, M.
I see other audio forums have the same type of complaint --looks like a design issue .
One website had contact "specialist " in Audiolab-
kevingreen@kgreen.co.uk
Everything done digitally on this amplifier ?
One website had contact "specialist " in Audiolab-
kevingreen@kgreen.co.uk
Everything done digitally on this amplifier ?