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Howdy folks, just wondering if anyone has an idea about what would cause the DC filament circuit in the Traynor YCV40 to blow. I have attached the schematic showing this circuit. Its the two flameproof 100 ohm resistors that are toast. Any ideas would be helpful.
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That is AC, not DC. The 100R resistors are the ground reference. They can blow if there is an internal short in one of the tubes (usually the power tubes), or if a power tube guide pin breaks off and the tube gets installed off key.Originally posted by Enzo
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Coincidentally, there is also a pair of 100 ohm resistors in series with two preamp tube heaters running on DC.Education is what you're left with after you have forgotten what you have learned.Comment
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Could be a preamp tube that's arcing from plate to heater through the cathode material, putting b+ on the heater supply to ground via the 100R resistors. More common in CF designs, but worthwhile replacing the resistors and powering up without tubes. 1/8W seems fairly close and I'd expect them to fry eventually on their own without any other fault. 1/2W is more usual.
Does the amp work anyhow?Last edited by Mick Bailey; 05-04-2013, 12:36 PM.Comment
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