I spent a couple of hours now trying to figure this one out and I think I'm out of ideas. The left-channel output of my turntable (or phono-amp) seems a tad louder than the right. It's small - about 1-1.5dB if the VU meters are correct. It was around 2-2.5dB off but after adding another rubber mat to increase the height of my platter, adjusting the tone-arm height, switching out the headshell, re-adjusting everything as if it was a new setup, I seem to have improved, but not eliminated the bias.
Is that just a fact of life or does anyone else have any ideas? Oddly enough, the bias seems worse on a mono 7" I have than on stereo records but it's still there no matter. I thought it might be the anti-skate but no setting of that (in spec or otherwise) seems to really affect that much.
The cartridge (a Shure M97xE - my first), is about 9 months old. My DJ cartridge (an M44G) also has the problem, albeit to a lesser degree. Since my M44G is almost brand new, I assume it's not an issue with stylus wear but that's the only thing I can come up with at this point (unless my phono amp is flawed).
Anyone have any thoughts or suggestions?