...I have been enjoying my new Torii for about 4 months now and have a question on volume between my left and right side...lm new to the tube amps so bear with me...from the time I first fired my amp up l have had to turn the left side up a little more then the right...to give you a idea how much, I have chicken head knobs, the left is set to 1:00 o’clock and the right is set to 11:00 o’clock ...this evens both sides out (left/right) to same volume output...I run this amp roughly 3-4 hrs a day so my mindset was maybe it needs some hrs on it to balance out, but the only thing that has happened is it is sounding better and the volume difference between each side has stayed the same...talked to Steve yesterday and he wanted me to change all the tubes from the right to the left and the left to the right to see if the output tubes we’re miss-matched... I did that and found out that it did change ....now the left side is stronger than the right so we know that it’s a tube problem...while laying in bed last night I was wondering about this and I did not know if this is something that you just live with owning a tube amp or if you deal with it and get it to even out...I thought when I get up in the morning I’m goin to move just one tube at a time and see if it changes...so I switched the two input tubes (6922) and fired up the amp ...to my surprise the higher gain moved back to the right, just by switching the input tubes...can this be the problem ?....I was thinking it would be the output tubes...would a bad input tube cause this to happen?...would appreciate any help from a member who has a little more knowledge on this than I
Thanks
Greg

Greg, an imbalance between two channels doesn't have to mean that a tube is bad, just that the two tubes aren't matched. End result is that channel imbalance you have experienced, which is a bit more extreme than it might be. As you have dual controls and can control the balance I would listen to some mono material and see if you can get a centered, even sounding image. If the mono signal sounds really odd or if the tonal balance is very different from one channel to another you may want to consider a matched pair of tubes to replace that pair.

Room and speaker placement can also cause channel imbalance, but if that changed with moving tubes from side to side it's not a room issue.

As Archie says over time it would surpise most of us if you didn't end up with extra tubes to experiment with and as backups and substitutions. When you do find a complement that has "equality" and balance between the two channels, they should most likely wear evenly over time and give you good service. If you have tonal balance that is very close between channels and you can adjust the channel balance and are comfortable with that sound, there's really no necessity to change tubes.

Bingo,

Simple as that, an input tube can and usually is the most likely culprit. This is because the input tubes have more gain than the output tubes. Think of output tubes as turning gain into current. So gain is where it's at.  Gain is what effect audible channel balance. Even when tubes match when they are new as was the case with your amp when it left my bench, sometimes  they will drift to a final landing place that is no longer matched.  This is less common with new old stock tubes from the 1950's, 1960's but even then it happened.  The beauty of this story is that the designer of your amplifier knew that in the real world perfect tube matching is not something that happens by chance and many times great sounding tubes won't always match in output.  This is why the amp has a volume control for each channel.  Do not worry about the small difference in volume between left channel tube and right channel tube if you like the sound... those positions are only relative to each other and have no real effect on sound quality.

Steve

Steve,

So if a person went with a stepped attenuator, would this still be a concern? As in if I was experiencing the channel imbalance Greg is, the attenuators only have a fixed distance they can move. Is there a change we can't achieve good channel cohesion with them and it's actually a better idea to *not* use the stepped attenuators with dual channels?