I have an SWR 350x Pro, and I'm aware of the SWR explained speaker pop on power-on, but I have a similar, but likely unrelated problem. When I turn the amp off, I often get a high-frequency transient pop - sounds almost like a static discharge. It does not happen every time, and it seems to be more likely to happen if I turn the amp off just a few minutes after I turn it on. The pop is sometimes quite loud, sometimes soft, and often not there at all. I am always careful to turn both the input and master volumes all the way off before shutting down, but this has no effect, and have been unable to come up with any specific combination of actions the either always cause, or eliminates the pop. It's done this since purchase of the amp. I bring it up as an issue because the horn on my Avatar 2x10 is blown, and I don't drive it hard enough to have done that on my own - I'm wondering if this transient is the culprit. Anyone else have this problem? Again, it's on shutdown, not power-on. Should I have this looked at?