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Old 16th August 2010, 06:19 PM   #1
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Default Bypassing cathode resistor on pp power tube

I currently travel across canada and i have a small repair to do for
a friend the amp is a custom special 100 traynor
the four cathode resistor of the power tube blown
it should be easy to replace them but Im staying in this town
for a limited time and theres no electronic part supply in the region
im relatively new to guitar amp repair but i know theres a lot of desing
that just dont use cathode resistor
can i just bypass them?

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Old 16th August 2010, 06:57 PM   #2
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Location: Small village, Israel
Do you have a schematic of the amp?
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Old 16th August 2010, 07:32 PM   #3
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Location: Midland, Michigan
If the Cathode resistors are blown, it's a good possibility that the output tubes have been drawing excessive cathode current. If the resistors were in the original design, I would not bypass them.
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Old 16th August 2010, 07:38 PM   #4
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Check bias rectifier.
The Devil is not so terrible as his math model is!
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Old 16th August 2010, 09:39 PM   #5
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I dont Think Traynor uses autobias. If anything they are screen resistors, or something Else. Either way there is probably a reason for the parts to go bad and u need to find that out first. Wavebourn has a good point since it must be something in common to all tubes if all related resistors are blown.

Look here:
Bargain Bin Heaven Amp Schematics - Airline Garnet Gretsch Hagstrom Kalamazoo Kay Magnatone Selmer Silvertone Supro
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Old 17th August 2010, 11:53 AM   #6
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Traynor has the user manuals with schematics online.

Looks like they are 1R resistors. If all four blew, something else is wrong. You can jumper over the resistors, but something else is going to blow, like the tubes. Failed bias would explain it.
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