TheGrumpyOldMan
500+ Head-Fier
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- Feb 19, 2012
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Welcome to the fickleness of tube amps...
There is a possibility it could be the rectifier tube since it determines the amount of power getting to the driver tubes, thus how strongly they can drive each channel. Not sure about the exact topology of the WA6SE, but the 274B can provide voltage to each side separately and if there is an issue with one of the cathode/anode pairs (even with a new tube like yours) that may cause this imbalance problem.
Another thing could be a mechanical contact issue, maybe use a flashlight and check the sockets (tubes should be OK since you swapped them without swapping the imbalance), to make sure nothing is bent, obstructed or loose in the pinholes. It could also be a faulty cap etc. inside the amp. If either of these things go wrong, you'll have most likely have to send it in for repair.
But hopefully it's just a tube issue. Since you tried the driver left/right swap, definitely try the rectifier tube. And since the SE uses an umbilical cord between the two halves, disconnect it completely, check for bent pins/pinhole damage that may cause a contact problem, then tightly reconnect.
P.S.: Also be aware the a 274B provides less voltage/power than the 5U4G usually provided by Woo. Shouldn't matter, but if there's one thing I've learned with my own tube-rolling experience it's that there are many parameters and characteristics to tubes, even within the same compatible family, and these interactions are not always as simple. I.e. the drivers may not be well matched, though with sufficient power they will be OK, but in an edge case it may just be enough for one tube but not the other. Though since the issue didn't switch after the tube swap, it's not likely in this particular case.
P.P.S.: While swapping tubes with the amp off is a good way to check things, I would NOT advise to wiggle them while ON; if there is a contact issue and it is lost and thus the circuit interrupted, then even maybe reconnected, very bad things can happen. Most people wouldn't open a powered-on solid-state amp and pulling on/plugging the live components or shorting out the wires either, and just because on many tube amps part of the circuitry is on the outside (the tubes) that doesn't make any more a good idea...
There is a possibility it could be the rectifier tube since it determines the amount of power getting to the driver tubes, thus how strongly they can drive each channel. Not sure about the exact topology of the WA6SE, but the 274B can provide voltage to each side separately and if there is an issue with one of the cathode/anode pairs (even with a new tube like yours) that may cause this imbalance problem.
Another thing could be a mechanical contact issue, maybe use a flashlight and check the sockets (tubes should be OK since you swapped them without swapping the imbalance), to make sure nothing is bent, obstructed or loose in the pinholes. It could also be a faulty cap etc. inside the amp. If either of these things go wrong, you'll have most likely have to send it in for repair.
But hopefully it's just a tube issue. Since you tried the driver left/right swap, definitely try the rectifier tube. And since the SE uses an umbilical cord between the two halves, disconnect it completely, check for bent pins/pinhole damage that may cause a contact problem, then tightly reconnect.
P.S.: Also be aware the a 274B provides less voltage/power than the 5U4G usually provided by Woo. Shouldn't matter, but if there's one thing I've learned with my own tube-rolling experience it's that there are many parameters and characteristics to tubes, even within the same compatible family, and these interactions are not always as simple. I.e. the drivers may not be well matched, though with sufficient power they will be OK, but in an edge case it may just be enough for one tube but not the other. Though since the issue didn't switch after the tube swap, it's not likely in this particular case.
P.P.S.: While swapping tubes with the amp off is a good way to check things, I would NOT advise to wiggle them while ON; if there is a contact issue and it is lost and thus the circuit interrupted, then even maybe reconnected, very bad things can happen. Most people wouldn't open a powered-on solid-state amp and pulling on/plugging the live components or shorting out the wires either, and just because on many tube amps part of the circuitry is on the outside (the tubes) that doesn't make any more a good idea...