I recently acquired a pair of pre-build second-hand T15 preamps. Given that there are no calibrations or trims, I am under the impression that each properly operating T15 should have almost exactly the same sound and amount of gain. However, in my case, one of the T15s is significantly more loud than the other, to the degree that I have to turn down the rotary knob by about two clicks for it to match the quieter one (yes, this is with the exact same source material).
I'm assuming that ordinarily these should work perfectly as a stereo pair, and that the quieter preamp has something wrong with it. THAT 1512P [U1] seems to be a culprit in low-gain issues on this forum, but before I replace it, is there anything else I should be looking at or know about?
This is abnormal behavior, correct?