Channel imbalance

[kill_surf_city]

I had this problem before, and it seems to have arisen again in my build. I was ripping an LP and whilst doing so I could hear and see in the waveform that the right channel is around 2-3 decibels louder than the left. It’s not very noticeable through my speakers, but through headphones it is pretty apparent. Is there a place in the build where I should look for poorly soldered joints? The imbalance according to the waveform isn’t just the noise floor, it affects the music as well.

[Paul Birkeland]

Try swapping the EF86s to see if the imbalance follows a tube.  Also be sure the DC voltages are correct. 

Beyond that, you could examine the channel imbalance at 20Hz, 1kHz, and 20kHz to be sure that it's close to the same at all those frequencies.  If it's not, then there's likely a flaky joint in the EQ of the louder channel.