[Mark]

As I crank the main faders up, they get closer in volume, but the left
is always lower than the right.


When you crank up the main fader, they get closer in volume AS
MEASURED IN dB or just the LED indicators are closer together in
distance?

Is the sound level at the output also unbalanced or only the meter
indication is unbalanced?

Sounds like you simply have low gain on the left side for some
reason..

Mark