Wurlitzer 4480 D# not sounding, Ds sounding an octave higher...what to do?

[AnnD]

We have a Wurlitzer 4480 that we are trying to repair. There is no sound from any of the D#s, unless the Nazard 2 2/3 is pulled. Also, all the Ds on pedals and both manuals sound an octave higher, except the top two Ds. Any suggestions on what to do next?

[KC9UDX]

It sounds like you have one dead oscillator. I have a Lowrey that does exactly this, and the culprit is a wonky 6X4 that only works until it warms up. The problem was originally F but I swapped tubes between F and D# until I get my hands on a replacement.

[AnnD]

Where would we get a replacement oscillator, and do you know the cost? We are also looking for a schematic of this organ with no luck.

[Admin]

The D# master oscillator is not working. The Nazard 2 2/3 is mutation stop that sounds at an octave and a fifth higher than the note played, so if the D# oscillator isn't working, you won't have working Nazards on F#s.

The problem with pedal is in the frequency divider circuitry.

Sorry I can't be more specific.

[AnnD]

Do you have any suggestions on where to get a D# oscillator? And possible a schematic of this organ?

[AnnD]

Why would none of the Ds be sounding? Is that related to the oscillator as well? The D#s are an octave higher, but no sound from any Ds.

[AnnD]

Thanks, any suggestions on where to go for more specifics on this organ?

[KC9UDX]

It seems you have more than one dead oscillator. This may be as simple as tube pin corrosion, or it could be very complicated.

[AnnD]

Thanks for your comments. It doesn't appear to have any corrosion when we look at it. How would tube pin corrosion look, and how would it be repaired? We are trying to decide if this is worth our time. We don't want to spend a lot of money on it.

[AnnD]

Do you have any suggestions on where to find a schematic of this organ?

[Admin]

There's a downloadable version for $6.50 here
https://www.emanualsbank.com/wurlitz...e-manuals.html

[tucsondave]

Not likely a tube since the 4480 is all transistor.

PM me an email address if you still need the schematic.
td

[AnnD]

Sorry to bother you again, but we need some help. My husband, Lee, replaced the master oscillator transistor, buffer oscillator transistor, and first divider transistors with no change in the organ. The D#s are still not sounding at all. Could any of the other divider transistors cause all the D#s not to work? Also the Ds are an octave higher. Any suggestions? My email is **********@gmail.com. We are in Rexburg, Idaho.
Thanks, Ann

[Admin]

I've removed your email address from your post as a security measure. People with information should contact you through the forum's private messaging. You should receive a notification email when you receive a private message.

https://organforum.com/forums/forum/...-email-address

[Admin]

Do you know that the D# master oscillator is working after changing out the transistors? It's going to be difficult to fix this problem without a schematic and some means, either and oscilloscope or aural probe, of tracing the signal through the system.