Excellent trouble shooting advice from Tvad. I'm going through that same process here trying to find a noisy tube among about 70 in my system.
Matt, just keep in mind that if the only thing off is a channel imbalance, and if otherwise everything sounds fine, and if you can correct for the channel imbalance by adjusting the balance control, you're probably just fine if you can live with that. There's nothing inherently wrong in a tube setup having a bit more gain in one channel than another as long as you can compensate. As the tubes age and change, this can happen. And it may not be worth the cost of having matched tubes across the two channels just for this.
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Matt, just keep in mind that if the only thing off is a channel imbalance, and if otherwise everything sounds fine, and if you can correct for the channel imbalance by adjusting the balance control, you're probably just fine if you can live with that. There's nothing inherently wrong in a tube setup having a bit more gain in one channel than another as long as you can compensate. As the tubes age and change, this can happen. And it may not be worth the cost of having matched tubes across the two channels just for this.
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