Crackling coming from Right Speaker - Help

I recently began my journey into the world of tube amplification. I purchased a Genesis I60 on audiogon, and have been extremely pleased with the sound. I moved from a floorstander (Legacy) to a monitor (Focal 906). In the past month or so I have heard a crackling sound through the right channel periodically. It has been present with both sets of speakers. Being a bit of a novice, I am not sure if this is an issue with an aging tube, a cable issue, etc. Any help or guidance would be greatly appreciated!
Noisy (bad) tube or tubes.
It could be any of the above. I'd check your interconnects and make sure you are properly grounded. You can even open things up and look for a loose contact. If that does not help then eliminate items by substituting things.

For example wire your power amp in reverse (left to right speaker and right to left speaker) and see if it moves to the left speaker. If it does not then you can eliminate your power amp as the problem.
To follow Shadorne's lead applied to the tubes. Check the tubes the same way move from side to side one tube at a time to find which tube is noisy or to eliminate them as a problem.
When I put a line conditioner in my system, the crackling noise stopped. A multimeter line check showed that the voltage was going from 118 to 140 volts within seconds that summer.
The Tripp lite line conditioner LC1200 solved this problem relatively inexpensively. This is definitely not audiophile-grade equipment, but in this case it worked without having to deal with tube diagnosis issues.
Thanks for the quick help here. I currently am using a power conditioner, so will try the tube rotation idea first and then look at other connection issues. Is it possible to be an issue with a power cable? That is the last new cable that has been added in the system. I am not sure when I first noticed the crackling/fuzz, but who knows sometimes.
P.S. - I assume I would need to rebias if I switch the tubes over - correct?
Before you do anything else: Next time you hear the crackle, tap each of the tubes in that channel with the eraser end of a pencil. It the sound gets worse, or disappears- you've found your culprit. Start with the driver/phase splitter tubes, as those usually generate that type of sound when faulty.
You'll generally need to re-bias only when changing amplifier output tubes. Small signal tubes can be swapped or "rolled" without having to re-bias.
Rodman99999 thanks. Sounds like some more great practical advice. When you mention the splitter tubes, I am not sure where to start. The tube compliment per channel is # Power Tubes (per channel): Two KT88
# Tube Complement (per channel): One 12AX7, two 6SN7.

Just start with the smaller(dual triode: 12AX7/6SN7) tubes. Not that it would really matter which you happened to tap on first, but those seem more disposed to the type of sound you described.