DonM, do you mean put the left output in the right and vice versa?

DNJ, yes I tried connecting to the RCA connectors my Roland Ba330. Same cables. No problem.

well then if it seems to be ok using the Roland amp with same hookups then the BOSE could be defective wouldn't you say...? How many return units have you tried so far of the bose?

No, what I meant was the power cable. It will fit either way. I don't think the polarity is reversed, but it would only take a second to turn it over and plug it back in just in case.

DonM and DNJ, here's the answers to your questions. I'll send this to Sweetwater as well.

Would you try and put a ground lifter on each of the AC cable ends that plug into the power strip. A ground lifter is a little gizmo that converts a 3 prong ac plug to a two prong plug.

Try using a stereo 1/4" cable between the audio out of the PA-900 and input of the Bose. Also do you have the volume level of the microphone channel turned off?

Sorry I didn't get to try mine today. It seems to me that it has to be something in the Bose doing it though.

No question in my mind - it's a ground fault conflict. If I were there I believe I could isolate the problem fairly easily, but unfortunately, you are 1200 miles away. Wish I could be of more assistance.

Gary

But Gary the Roland amp works without hum, hooked up exactly the same.

And there is no hum using the 1/4 inch connector.

Hi salsaman, did you get a chance to watch the video? What would using a 1/4 inch stereo cable solve?