Dean Markley CD60 -- issue with reverb

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Dean Markley CD60 -- issue with reverb

Postby Charmless on Sat Jun 18, 2016 2:30 pm

Hey gang! I've got my tech resurrecting an 80's CD60. and he's having issues getting the reverb up n' running. any thoughts on below?

'the transformer ohmed out okay, but the reverb is still not working properly. Don't know what the problem is, but the signal gets to the transformer and then nothing comes out. Replacement transformer might fix it. It's such an obscure circuit that it's kind of hard to know. I'll look at the FET switching matrix and see if that is f'd up. '
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Re: Dean Markley CD60 -- issue with reverb

Postby Dean Jr. on Sat Jun 25, 2016 7:41 pm

I have encountered reverb driver transformers that looked good on an ohmmeter but would not function in the circuit.
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Re: Dean Markley CD60 -- issue with reverb

Postby stratele52 on Sat Jun 25, 2016 9:16 pm

If you have a signal at transformer input, the amp SEND circuit is working.

To test the amp RECOVERY circuit where is the transformer secondary, disconnect secondary and put your finger on the + wire. You should hear a "hum" at speaker.
There is no dangerous voltage there.
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Re: Dean Markley CD60 -- issue with reverb

Postby Dean Jr. on Sat Jun 25, 2016 10:54 pm

stratele52 wrote:If you have a signal at transformer input, the amp SEND circuit is working.

To test the amp RECOVERY circuit where is the transformer secondary, disconnect secondary and put your finger on the + wire. You should hear a "hum" at speaker.
There is no dangerous voltage there.



The reverb DRIVER transformer is part of the Send function, ime.
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Re: Dean Markley CD60 -- issue with reverb

Postby stratele52 on Sun Jun 26, 2016 12:06 am

Dean Jr. wrote:[

The reverb DRIVER transformer is part of the Send function, ime.


Yes but it is not the only part.
I'm talking about the other circuits of the amp.
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Re: Dean Markley CD60 -- issue with reverb

Postby stratele52 on Sun Jun 26, 2016 8:55 am

If the amp itself work after test SEND and RETURN circuit and the reverb pan is OK ,transformer must be bad.
Where can you find a DM reverb transformer ?
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Re: Dean Markley CD60 -- issue with reverb

Postby Dean Jr. on Sun Jun 26, 2016 9:10 pm

stratele52 wrote:
Dean Jr. wrote:[

The reverb DRIVER transformer is part of the Send function, ime.


Yes but it is not the only part.
I'm talking about the other circuits of the amp.


stratele52 wrote:If you have a signal at transformer input, the amp SEND circuit is working.

To test the amp RECOVERY circuit where is the transformer secondary, disconnect secondary and put your finger on the + wire. You should hear a "hum" at speaker.
There is no dangerous voltage there.


stratele52, we must have a language barrier. Just because there is a signal/voltage on the incoming side of the reverb driver transformer does NOT therefore mean that the SEND side of the reverb driver signal is working. That signal has to come OUT of the driver transformer to the tank,through the tank and through the return path.

charmless, what happens when you shake the amp...do yo hear the reverb function? IF not, then the signal is NOT coming back from the tank. IF you hear a reverb function when shaking the amp, then your problems are in the reverb circuit prior to the return inductor in the tank.
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Re: Dean Markley CD60 -- issue with reverb

Postby stratele52 on Mon Jun 27, 2016 8:32 am

Dean Jr. wrote:
stratele52, we must have a language barrier.



+1
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