Many thanks for the ideas John \u2013 I shall certainly take a look around the cct and will certainly let you know how I get on.
Brian
-----Original
Message-----
From: John Brewer
[mailto:john@...]
Sent: Friday, October 29, 2004
10:59 AM
To:
vintagesynthrepair@yahoogroups.com
Subject: [vintagesynthrepair]
Wurlitzer Hiss
Hello Brian.
I have not worked on Wurlitzers but I was interested in your problem.
OK, so the fault is common to both manuals but not pedals. How is the manual keying done on a 630. Is it done by diode switching? The first thing I would do is look around the keyboard and find the source of the keying voltage. From your description I would say the noise is on there. Just another thought. Wurlitzer???? Immitation theatre organ??? Does it have any kind of Brush/cymbal white noise generator in the organ. These trigger from the keyboards and if not set correctly can give a continuous noise rather than a brief pulse. Some white noise is also added to snare drums.
As you have the drawings, you should be able to locate which section of the organ is sending this noise to the pre amp.
Good luck. Let me know how you get on.
JohnB