Experiencing speaker imbalance, while amp headphone output is fine. Any ideas?

might be room acoustics... is the room and speaker placement and reflective surfaces symmetrical?

or else it may be the amp... try swapping tubes in one channel to the other, one at a time, see if the imbalance shifts

tighten, redo all wiring/connections

even well tested tubes, shipped, handled, packed/unpacked, can sometimes suffer from a version of infant mortality

op - wish you good luck, arc should and will take care of you

@gnarmite

glad you figured it out

did you take @oldhvymec ’s advice and get pepper spray too? he also keeps a fire extinguisher handy next to his listening chair too, as i understand it

great mechanics are always prepared... 😂👍