Seventh Circle Audio

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?

Seeing as these forums are all but abandoned (no product support anymore? Or just by email these days?), I never received any definitive response, but I did end up answering my own questions. So for anyone in the future wondering the same things:

Yes, they are naturally balanced to each other if they are working properly. It's interesting that even though I had one that passed audio and seemed absolutely normal, it wasn't working properly as evidenced by the second T15 with higher gain. I would have had no idea that it wasn't 100% if I didn't have another to compare it to. I think the original owner/builder was oblivious to any issues because they never tested them on the same source material or used them as a stereo pair.

I ended up getting a couple sockets and both THAT chips and swapped them out. It was worth the $12 repair bill. I probably didn't need to replace both chips but I figured I might as well be on the safe side since it's only $5 more and the soldering iron was already hot.

Happy ending.

I also have to say that even though these are supposedly the "budget" SCA preamps, they do sound very, very nice. I also have the N72 and A12 pres and I think the T15 is right up there and could even be preferable depending on what you're trying to do. Don't overlook them just because they're less $$$.

Hey just picked up a pair of the T15s , havent arrived yet. thanks for the advice on fixing yours. Man i have the C84 and that pre blew my mind when i first heard it. I also have 2 N72s. Im hoping the T15s are close to the C84 cause that is an amazing clean detailed pre. peace