Question for electronic component-level bench guys...Sennheiser EW300 G3 wireless In-ear monitor unit with the usual external power supply (wall-wart) powering the transmitter (the unit that goes in the rack). For a few weeks now, the transmitter unit was slow to power up. At first, it would take a few minutes to power up, then it progressively took longer until finally this last weekend, 45 minutes on Friday and 4 hours on Saturday (didn't have it for the first set. Great, time to send it in. I checked the wall-wart, it was showing 12VDC. For proper trouble-shooting purposes, I dug out a generic wall-wart with the proper specs (I have a drawer with over 200 wall-warts from long-gone devices. Need one? Hit me up) and the Sennheiser unit powers up immediately every time. So it's the wall-wart instead of the $275 flat-fee that Sennheiser wants for repair (Hey, I'd get new guts for the unit, but...). The question revolves around the wall-warts. The Sennheiser wall-wart is labeled as a "switching PSU". My generic out-of-drawer wall-wart is powering up the unit just fine and sounds as it's supposed to. Why the need for Sennheiser's switching PSU? Some kind of filtering over the generic unit I"m using now? I'm a big believer in using gear at the specs it was intended, so I intend to buy the Sennheiser replacement wall-wart. Just an inquiring mind at work. Thanx.