Funny noise from Tube system

Back in the good old days, tubes farted all the time. 

I have a Rogue Magnum 99 also. It’s suffering the same issues that you have But only on the left channel. I do not have an amplifier as I use amplified speakers. I live in the Colorado foothills. We get a lot of Lightning, even in the winter. (2nd only to  Florida).  Our grid system when struck by lightning, turns off for a split second and then  immediately back on.  Guessing that’s not good for sensitive electronics. I sent it to my local shop, who are quite good. They could not hear popping. They charged me $60 for diagnostics, but could not even hear it.  So I send it to Rogue and had it “Supered” while it was there as the repair cost is $250. ($600 for the  upgrade which included the repair) ALL good! Fantastic!
 I ran it for a week. And was awakened at 2 AM to very LOUD popping and no signal.  (Oops-maybe lightning? see my other recent post on the same topic-LOUD popping on Rogue. (Thank you all again that offered advice).  I had that repaired by my local Audio repair shop.   It’s still suffers, again, from fizzing and tapping-sounds like Fred Astaire with canastas.  
My repair person said he can’t fix it because he can’t hear it. I’ll bring in my Focal speakers, maybe that will make a difference at his shop.
BTW I really noticed the changes with the upgrade.  Worth the $. It will probably have to go back to Rogue again. $200 shipping plus the repair. Ugh! 

Depending on your listening habits, you could be well over 3000 hours on the pre-amp tubes since 2001. 10 hours per week for 6 years = 3120 hours of on time. 20 hours per week for 6 years is 6240 hours and 30 hours of on/listening time per week is 9360 hours over the course of 6 years.

Since the problem goes away when you place the pre-amp on mute, you know the issue is not in the amp. I think replacing the pre-amp tubes is the next logical step.

TIC

Pre-amp tubes should be good for 3000 to 10,000 hours, depending on which tubes and which amp???

I think it's time for new tubes in the pre-amp....

TIC

I heard the same from my tubed system, but only out of one channel. I checked the tubes in the preamp, and, sure enough they were bad. I replaced them and that PFFFT sound went away. Roughly speaking my preamp tubes are good for about a year. Try changing them out if you con't have a tube tester.

I would ask Rogue. Since it's not there when you put on the mute switch it's not in the amps. While it could be tubes, it also could be a capacitor or even a resistor which only exhibits this behavior when it gets to a certain temperature. I had a similar problem with my JP80 preamp a few years ago, it took forever to find the problem (was a resistor) because to get to the problem component we had to take off the bottom plate, and when we did that it cooled off the resistor and stopped the problem. A good technician should be able to find it, but Rogue is best equipped to do the trouble-shooting.

Keep the mute switch on

The electrons are revolting against being forced to work with the tubes.