Dave's PSR 3000 seems to be throwing a 'hissy' fit.

PS: A good test would be to try another PSR 3000 and do all the things Gary did to his to try and get it to hiss. If and when you find one that doesn't hiss, immediately purchase it and sell the hissy one preferably to someone who doesn't mind a little hiss. Either that or to a person who is hard of hearing and wouldn't know the diff anyway.

Better yet, send it back to a Yammie repair shop and tell them to fix it ASAP. That way you wouldn't be dumping off a faulty product on someone else Dave. It's under warranty right? So let Yammie fix it if it bugs you enough to be annoying to you and more importantly annoying to your audience.

You may have gotten a rotten apple in the otherwise vast majority of hiss-less ones. It might be something faulty in the Keyboard's innards. Either that or your house line A/C current is fluctuating beyond the norm and possibly causing the hiss. You may need a line conditioner UD.

Maybe it's not isolated to just your home either. Could be the whole Philly area, who knows? So you may have to drive quite a distance to find a hiss-less one if you decide to do the 'hiss' test.

Best regards,
Mike