Unbalanced hearing

I got a dual mono int amp. 2 channel volume

I also have the same issues. But artificially correcting it in these ways does not work. You can't fool yourself, ie: your brain. Listening to a correct presentation is still the most pleasing. You need to be able to identify the same sonic placement cues since you are actually able to do so, even if you were totally deaf in one ear. Your perception of space and time depends on it the same as when you are not listening to your rig. It's something you simply have to live with.

Nearly every human being has some imbalance, just do your best.

Thanks for those responses. I've played with the balance control on my preamp, but it doesn't work for me in a satisfying way. I use a Deqx processer, but it doesn't allow for independent channel compensation. Bojack, can the Behringer boost the treble to one channel only? Even if it could, I wonder if that would mess things up for the good ear, as you mention.
Maybe I should stick a little cotton in the good ear.