Luxman SQ-30u noise
I just replaced stock tubes with vintage tubes. I started hearing static/crackling/hiss in both channels. Noise increases and decreases in volume, and sometime disappears entirely, but always returns. Does not change with volume setting (same at min and max volume). Does not change between phono or CD selection. Not noticeable when playing through speakers, but, somewhat distracting with headphones. Overall, I think the sound is enhanced with the replacements.
Noise obviously resulted from tube switch. Since I know nothing about electronics, is it more likely the power tubes or EC82/EC83s are the problem? I really don't want to put the no name tubes back in. Or should I replace 1 at a time to find the noisy offender(s)? Thanks in advance.