hi to all i new on forum, i have a opus III, and i am reparing, i cleaned all the pots of the punk foam, but i can’t get the filter works good, the emphasis doesn’t work, perhaps the emphasis trimmer has a low voltage, i don’t know if is normal I test the Cutoff trimmer and get me 15 volts, but the emphasis trimmer get me 4.6 volts, perhaps is this the problem? or is problem of the ca3080a?
thanks in advance.
Fernando.
for future emphasis problem users, i solved the problem with the help of Steve Jones, Yves Yusson and me of course, i take advice to them about U26, looking again and again the schematics, the problem was in the CA3080, U26, the emphasis trimmer doesn’t received the correct voltage, 15 volts, only had 4.6 volts, insufficient for resonate, you can sure testing the pin 4, to me gave me 0 volts, and had to give -15, the trimmer needs 15volts to resonate, i changed the CA3080 and emphasis comes again to life before 12 years, when i buyed.
now i have to repair other problem with la# keys, doesn’t sound, i think is the TDA1008, but i have to see very well.
Thanks to all for read my post, i hope this information could be usefull to everybody.
Dancelwerk.
All this stuff is good to know…especially for Opus III owners, who are few and far between. Thanks for sharing! Keep us updated on the repairs!