It's not the speaker. I checked that already.
No tubes to fail here though, this is a SS set.
I'm beginning to wish I hadn't junked the parts set I broke down to fix this set after I fell on top of it when I was totally sh*t-housed and blew up the picture tube. :/
A HV problem would make sense because the brightness dims somewhat sporadically whenever I hear this noise. I've never really had to mess around that much with internal circutry before, what would cause it to ripple? Bad caps? Corrosion somewhere?