Very odd sound problem - pops and sound cutting out

[spargo]

Recently my guitar rig had a problem during a gig.  I have my guitar into the pedalboard and then into a Jet City 20W combo.

While playing a couple weeks ago the amp let out a couple loud pops.  I noticed one of the power tubes was red hot.  So I replaced the power tubes, problem solved. (I think this was actually a separate issue perhaps)

A week later, a similar thing happened.  A loud pop here and there, but this time the volume also fluctuated a lot and the signal cut in and out.  I figured it was my amp again, so I plugged into a POD 2.0 and used a DI instead.  The problem persisted, so I turned ALL of my pedals to bypass (but still running through the board).  The problem still happened.  So I just plugged my guitar straight into the POD and the problem went away.

I had originally suspected my Barber Tone Press compressor, since I THINK the problem got slightly better when I bypassed the pedal, but I'm not sure.  What's difficult is now it seems fine and I can't reproduce it, but I don't want issues to happen at important times again...If it makes a difference the pedalboard is powered by a OneSpot (about 8 pedals), and had been on for about 3-4 hours.

Any ideas what may be the culprit?

[soupbone]

Those one spots can get pretty heated up.I bought a voodoo labs pedal power a while back,and I've never had any issues,because they're all isolated inputs.Definately worth the investment.

[petemoore]

Any ideas what may be the culprit?
  Preliminary analysis of the latest test results tend to rule out the amplifier.
  That leaves everything else.
  Sounds like a good bit of everything else...cables, jacks of many types, true bypass can be nice but also introduces mech-switches into the bag of 'could go wrongs'.
  Finding the problem is a bit like audio probing, but with patch cables. Processes of eliminations.
  Even the Non TB pedals can have wierd stuff like this.
  My 2 tier PB is in a scavenged state at this time, #1 PB with simpler line-up and Spyder seems to work well. 
   

[spargo]

I regularly have the OneSpot on for 2.5-3 hours with no problem.  What is irritating is that the problem would not reproduce!