Search found 3 matches

by Spyros12
Thu Apr 30, 2020 6:14 pm
Forum: HELP!
Topic: Oberheim OB-Xa tont Tune
Replies: 1
Views: 545

Oberheim OB-Xa tont Tune

None of the voices will tune after replacing a problematic Lm324n at the bender board. Before the replacement the Oberheim worked like a charm. My technician replaced all of the electronic components at the bender board and the problem still occurs. I unplugged the bender from the synth and run it w...
by Spyros12
Mon Jul 29, 2019 10:41 am
Forum: HELP!
Topic: Oberheim OB-Xa noise generator problem
Replies: 3
Views: 4416

Re: Oberheim OB-Xa noise generator problem

The problem was a transistor at the lower mother board. It is located at the upper left corner. This transistor has a green socket replace it with another. Watch out, you will need to cross two of the transistor legs. If I remember correctly the first one with the second.
by Spyros12
Sun Sep 23, 2018 2:53 am
Forum: HELP!
Topic: Oberheim OB-Xa noise generator problem
Replies: 3
Views: 4416

Oberheim OB-Xa noise generator problem

Well I get a strange sound from the noise generator. The problem is probably the MPS5172 transistor where the noise gets generated. There is a socket where the transistor applies. If I’m not mistaken a good replacement for that chip is 2n3904. I really don’t understand how the legs get into the hole...