Road King II problem (with soundclips)

[b0nkersx]

I've been getting some rare intermittent drop out problems with my amp. Before I go on, here's a soundclip:
http://www.netmusicians.org/files/16-RK%20problem%203.mp3
The quality is horrible (it's a rare problem so when it happened I jumped for my cellphone) but the volume change should be quite apparent.

The amp is a bit over a year old, but I've had the problem for a while. If I dig in to the amplifier, the problem disappears. My amplifier has the relabeled JJs, so Mesa doesn't think it's the standard cathode follower problem normal with many Mesas. I've had it looked at by a local tech and had it sent to Mesa but neither could replicate the problem.

I've had the problem with several different guitar and speaker cables, different power tube settings (all diode rectified), two different guitars, two different cabinets, and two different speaker output jacks. Loop is hard bypassed. It's not a bad problem at all, but it's one that I don't want to get any worse (especially at a gig).

Sound like a **** tube? Should I shotgun the tubes and see if it gets better? Any advice is greatly appreciated.

Thanks~

 

[GuitarGuy503]

If its been a year I'd say its time for a retube. Tube amps seem to do many different things when the tubes are going out (hissing and feedback, popping, volume drops, etc) If you retube the amp and the problem persists you know you have another problem on your hands. Your best bet is to always start with the tubes when your dealing with a tube amp.