Ampeg SVT 7 Pro - Strange symptom - intermittent popping

So I've read many of the threads about the svt 7's popping and cutting out, but this seems to be a little different and I could use some help. Mine has began making the pop that it makes often when taking it off standby, but it's doing it intermittently and doesn't cut out my signal. It's not SO loud that I can't play over it, but it scares me that something worse could happen if I continue to use it. I've done some tests, making sure preamp tube is connecting well, and I've bypassed the preamp and found the the power amp section does not make the noise. The EQ controls and master affect the sound accordingly... It also just started doing this randomly the other day. I use it 4-6 times a week and set it up the other day and it just started doing this out of the blue. Any help? Thanks so much!