Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: tubedue1 on June 03, 2019, 08:31:42 am
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I have a 65' Deluxe reverb re issue and the amp just rocks...one problem.....the reverb will switch on and off but the vibrato/tremolo will not turn of when switch with foot switch....foot switch is good..At the C24/R46 connection I get 13.6v switched on...off I get 3.7v ( per the schematic it should be "0". Also on C24 the schematic shows that the + side goes to ground...it doesn't..I jumpered it to ground...still won't turn off vibrato/tremolo. Anyone have this same problem? Email me if you have a solution to this problem.....kracked@swbell.net.......
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What voltages do you get at TP26? Post these voltages here and we'll help you work through the issue. Solutions will be posted here so others may benefit also. Email is not used.
The schematic I'm looking at shows c24 positive side properly connected to the cathode of V5B.
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At TP26 R40 tube side..-7.12v...other side -6.?? fluctuates..also as I said before..the + side of C19 has no connection with ground.The - side 7.4ish also fluctuares. C23 + side 1.08v...-side 0v
Thanks for your help...this is driving me nutz..This Fender 65' DDRI won't stop vibrato and I have an original Massie Mod462 that I can't get it to engage tremolo.
Thanks again..sorry to be so lengthy.
Ron
OKC
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also as I said before..the + side of C19 has no connection with ground.
You never said that. You only spoke about C24.
What voltages do you measure at V5 pin 2 with footswitch on and off?
What voltages do you measure at V5 pin 7 with footswitch on and off?
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Sorry about C19..I thought I had typed that in...Okay V5 Pin 2-footswitch on...-6.4
Pin 7-footswitch on..-6.4ish fluctuates
Pin 2-footswitch off..-0.1 fluctuates
Pin 7-footswitch off..fluctuates can't read
Thanks
Ron
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That's all normal. -6.8V should turn V5 off as expected. V5 should be a 12AX7. Change the tube. You can just swap it with any of the other 12AX7s. Any joy?
You say C19 positive lead does not connect to ground? Where does it connect?
And what is this Massie Mod462? Is this something you have done to the DRRI so that it is no longer stock? If so, please tell more about the mod.
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Well I did put a known good 12AX7 in V5..before he bought I believe someone switched out the 12AX7 with a 12AT7 in there. Works good.
Thanks so much for your time.
Ray Massie worked with Leo Fender for many years then split off to make his own amps. This one is a model 462 blonde head. 2-6V6's, 6CA4 rectifier, and 3 original Mullard 7025's. Awesome amp...sounds great.
Thanks again
Ron
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Well I did put a known good 12AX7 in V5..before he bought I believe someone switched out the 12AX7 with a 12AT7 in there. Works good.
Thanks so much for your time.
Ray Massie worked with Leo Fender for many years then split off to make his own amps. This one is a model 462 blonde head. 2-6V6's, 6CA4 rectifier, and 3 original Mullard 7025's. Awesome amp...sounds great.
Thanks again
Ron
So the issue with the DRRI was wrong tube plugged into V5?
And the Massie is a separate amp that has a different issue?
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Yes, it turns the tremolo on and off...however you can hear the fluttering of the opto-isolator through the speaker when your using the tremolo. Puzzling...some component is allowing the fluttering to be heard. When he got this amp it had a mixture of tube brands...suggested he get a new set from Eurotubes. Someone had also put the rectifier in one of the 6L6 sockets and the a 6L6 in the rectifier socket. The 6L6's got so hot the GT sticker label came off......he got it at the big G store...
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The DRRI sounds great..the reverb switches on and off as well as the tremolo..however you cna hear the fluttering noise of thee opt-isolator
When it on..strange
Ron
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That's a common complaint with the neon bulb type optoisolators.