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Post subject: Grounding issue with Twin Reverb Reissue
Posted: Sat Jun 05, 2010 11:33 pm
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Hey guys I'm having a issue with me new old twin reverb reissue. I was having a strange issue in which my guitar would buzz unless I was touching the bridge pots or strings. Through the use of other guitars, cables and a friends amp I traced the issue to first input on vibrato channel. I couldn't recreate the buzz in any of the other channels and it does not make the noise when I'm touching any of the various parts mentioned for I figure this means its grounding through me. I wanted to know if anyone else has experience any similar issues and if so how did they fix it. Thank you in advance.


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Post subject:
Posted: Sun Jun 06, 2010 1:21 am
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Hi,

Are you talking about '65 twin reverb reissue ?

On normal input you have high level input (1 Mohm grounded) and low level (2* 68 KOhms gounded divinding the level rougly by 2 (-6dB).
Do you have also the pb with the low level ?

Actually, the Vibrato and normal first stages are exactly the same, that why you may have an issue with the jack female or soldering issue on the normal one.

If you open you amp, take care about HV (450V DC) that can kill you.

Tissan


:wink:


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Post subject:
Posted: Sun Jun 06, 2010 1:44 am
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its a twin reverb reissue, yea thats strange I don't get the buzz from normal channel 1, also how long do these amps normally take to discharge?


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Posted: Sun Jun 06, 2010 3:57 am
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Hi,

The pb is located in Vibrato high level input and not in low level input; Let me know if I'm right.

In that case the jack and/or soldering are likehoodely the root cause.

For the high votage:

1. Unplug the amp
2. Open it (rear with 6 screws I beleive)
3. Measure with a voltmeter the voltage on B+, Z,Y,X, make sure they are down to gnd otherwise use a 100K 2W (with wire and crocodile plug isolated) in // to the cap C32, 33, 34 to down the voltage (normally do does down to gnd in dozen of seconds. The supply are secured but always make sure that high voltage capacitors are down to zero then don't touch with your finger but with a plastic srewdriver for instance.

Tot siens

Tissan


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