Hello group....this is my first post so be gentle! I have a kef psw2000 which, after a few minutes of being switched on, emits a high frequency (low level) whistle accompanied by white noise. The wierdest thing is that the noise also makes it's way back to the amp (DSP-A2). Unplugging the coaxial cable shuts off the noise to the amp but the sub continues to misbehave. Sometimes during quite scenes the high frequency rises sounding like a distant siren, and then the sub switches to auto off with a thud. So far kef have been helpful and are willing to send me out a new amplifier unit for it, but it would be interesting to find out if anyone else has had a similar problem, is it common?.