What are you thinking, Gary? The exact same hum occurs with both the Pa900 and the Kurzweil SP4.

Hey Gary, have another Green Margarita .

chas

Graham, a couple of things come to mind, but the easiest way to isolate the problem is to use a simple, ground defeater plug, which would isolate the ground systems from each other. They're available in any hardware store, Home Depot, Lowes, etc...



Another problem could be your venue ground system, which is not unusual in older buildings, mainly churches and theaters. When I worked for Executone Sound Systems we frequently had to install earth ground systems in order for their sound systems to operate without encountering 60-cycle/HZ hum. The big tip off there was when people complained of getting bit by their microphone - an electrical shock when their lip touched the mic frame and they were standing on a bare, damp concrete floor. ZAP! This can be tested with a multi-meter, but if you don't have electrical circuitry expertise, this is best left to an electrician.

I've plugged just about every electronic musical instrument into my Bose L1 Compact that can be, and only once encountered a hum - and it was from a video recorder that had an external power pack (wall wart) plugged in. It hummed like crazy until I plugged in a ground defeater and the problem immediately ceased. I wish I lived a bit closer Graham, then I could come over and solve the problem in person. But you are about 900 miles away.


Chas, Another Green Coconut Margaretta sounds like a splendid idea right about now.

Hope this helps,

Gary.

Graham,

My Bose connects either from the Mono/left 1/4 inch output to quarter inch input on the Bose or from the stereo headphone jack with left and right (red and white) RCAs to input into the Bose. Either way works fine. I'm sure you eliminated this scenario a long time ago but make sure the switch for the Bose inputs is not set for guitar.

God Bless,
Don

Don, thanks, I have not tried the headphone jack. I'll try that.

Blessings

Did the headphone connection work for you, Graham?

God Bless,
Don

No, exactly the same problem, Don. Even Sweetwater are struggling.

The new Bose is defective also?

Yes, and Sweetwater Tech support seem to be struggling with what to do. I have asked them, if they want to send a third unit, to test it before they do. I suspect that most people do not connect their keyboard to the RCA connectors, and the problem may be more prevalent than Bose understand.

Graham, I'm gonna try connecting to the RCAs when I do tomorrow night's job. I'll let you know what happens.

Gary