left speaker is louder than right speaker

The off centered sound seemed to just happen the other day. It was with any cd I played. my only source is a Meridian cd player. I felt I narrowed the situation to the preamp. I switched out the 6 tubes with another batch I had. The left channel still dominated. I plugged my headphones in the built in headphone jack and the headphones played balanced. I unplugged the headphones and the speakers are now center balanced. Not complaining, but what's up!

Maybe some corrosion in the headphone jack.

I have a similar issue with my used C-J PV11 preamp. I will try mono, and switching around cables. No headphone jack, so I can't try that fix. I suppose there could be issues with other components in your preamp (caps, op-amps, etc.). In my situation, I think that the asymetrical layout is causing an acoustic imbalance between channels.

Start at the source Bondmanp. If it occurs when playing CDs, try reversing the left and right outputs on it.