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I recently built a mission 5e3 kit and am unable to get the bright channel working. My father just completed the same kit, independently of me, and is having the same problem. The normal channel, volume, and tone are working properly but the bright channel and volume are completely unresponsive. Everything appears to be in the right place according to the schematic. Anyone have the same problem/ know how to fix it? Advice would be greatly appreciated.
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I don't know if you both made the same wiring error or not as there are a few items that can cause the symptoms you describe.
The only differences between the normal channel and the bright channel are:
The 2 input jack pairs (Hi and Low), the 1M resistors on the jacks, the two 68K resistors on the eyelet board, the two wires from the 68K resistors over to their respective grid lugs (2 and 7) on the 12AY7 socket, the two 100K the plate load resistors (lugs 1 and 6), the two 100nF coupling caps over to the wipers of the volume pots and the actual volume pots.
Assuming the you and he do not have a 12AY7 with the exact same triode being bad, since the normal channel is working OK, it has to be a wiring error.
It could be the volume pot is not wired right but let's look at the 12AY7 first.
Check to see if the filament wiring is correct and lugs 4 and 5 are tied together.
Look at lugs 3 and 8 of the 12AY7 to make sure they are tied together and connected to the 820 ohm biasing resistor on the eyelet board.
See if each anode of the two triodes (1 and 6) is exhibiting a lower DC voltage then the supply voltage at the junction of the two 100K plate load resistors on the eyelet board.
The schematic has nominal voltages written on it... check to see if the two 12AY7 triodes (lugs 123 and lugs 678) have approximately the same voltages.
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