I recently bought the H/K AVR 320, so my old H/K AVR 20II is no longer in use. Over the years, the AVR 20II acquired a constant white noise, audible regardless of volume, both in the speakers and especially in the headphone jack. With the speakers, it is generally not noticeable after 3.5 meters, but I can't stand to plug headphones into it anymore. The noise is kind of a hybrid between white noise and a really high-pitched (like >15,000Hz) hum. Does anybody else have this receiver with the same/similar hum/hiss?