Right/Left channel balance issues? Pre-amp

Problem:

Long story short, I have bought a new integrated amp and through a long process of testing (and elimination) I have determined the preamp section is causing a 2 dB difference between the right and left channel. The integrated amp does not have a right and left balance...

This pushes my sound stage to the left and the vocals do not have the focus they should have. The 2 dB is in the mids and highs. The bass was not really measurable.

Question:

Is this common or am I being to picky? Does anyone know what type of balance tolerances are common on pre-amps, integrated amps? I REALLY like the piece but an strongly thinking about returning it. The integrated amp has bout 70 hours on it at this point and uses a single tube in the pre-amp section.

PS. I did not name the brand because I have asked the company this same question and do not want to give them a bad rap prematurely.