I have a friend selling a bose compact if anyone is interested.

Deane, when you use a mic do you channel that through your keyboard or connect directly to the Bose? The keyboard worked fine the way you describe, but there was no mic output from the Bose, only through the keyboard speakers.

That doesn't make sense. If your mic is going into the keyboard and the output of the keyboard is going into the Bose then it should all be reproduced.
Are you are losing part of the signal along the way? Could you be getting only the one side of the kb output and the mic is panned to the other side? Or is the mixer panned too far one way?
You should be able to run stereo out from left and right from the PA900 into the RCA stereo inputs on the Compact and get great sound. I have done exactly that with no problems.
If you aren't then it's either the cables or something is wrong with the Bose.
If you're getting the full sound but hearing noise, then it's most likely some bad cables somewhere along the line, either from the kb to mixer, or mixer to Bose. I never turn the Compact volume (input actually) past about one o'clock. Check the levels from kb to mixer and output of mixer to see if they are fairly hot but not overdriven.
If all this doesn't get results, call Bose. They are wonderful about helping you while on the phone. They will walk you through your setup.

First and foremost, try using another mic through the Bose without connecting the keyboard to the Bose. If this works, then there is nothing wrong with the Bose.

Now, about that hum. Do you have anything else plugged into the power strips, PC, etc... PC power supplies are notorious for causing hum problems because of conflicting ground systems. This can be overcome with a ground defeating adapter plug used with the laptop power supply.

Gary

The mic I was using was connected into the keyboard. That is what is so strange. Why would it work with a single cable connect, but not work with the double cable connect? When I disconnected one of the two cables at the keyboard the mic came through fine.

I already had an SM58 connected into the Bose and my wife was using that, and sang beautifully as always.

The only other things I have connected to the power strip at home are 2 Focal monitors and a Kurzweil SP4 (all of which were turned off). Anyway I noticed the hum with my setup in a Nursing Home, with a different power strip.

I tried connecting my iPhone into the RCA connectors and it played fine with no hum.

I'm beginning to wonder if the problem is in the keyboard outputs. I'm not out tomorrow so I'll set it all up at home again. First of all I am going to see if can set it up in the same way with a different PA system, and see if I get the same results. Then later call Bose.

I'm pretty certain it's not the case, but are you SURE you are using the correct output jacks from the back of the PA900? One time I had one of the cables plugged into the wrong hole, I think it was the aux in port, and it took me a while to figure out why I was getting only half the signal.
But them, I'm old and semi-senile.

No, there's just the 2 inputs and 2 outputs. Like you, I have plugged them in the inputs in the past, but it's the first thing I checked.

Sorry for the delay in responding - I have used my mic both directly into the bose and also through the keyboard. Both ways have worked great for me. Keep in mind I don't sing and use the harmonizer so going through the Bose Directly works ok for me. All said, I have never had any sound issues with the Bose setup and have used it with the following keyboards - Korg PA900, PA1x, PA1x Pro, KMA. Yamaha PSR3000, Tyros 3, Tyros 4, and PSR950, Roland E50, E80, and now my Ketron SD7. None of these keyboards causes any issues with humming or other problems with the Bose Compact.

Deane

Firstly I validated that the hum does still happen when I connect my Kurzweil SP4 into the Bose, so the problem is not the Korg keyboard. Then I found that it does NOT happen connecting into the 2 RCA connectors on 2 other PA systems. I called Bose, and they went through in detail with me and so we concluded there must be a fault with the Bose, so I am in the process of doing a return/ exchange with Sweetwater.

The loss of mic issue may be a different problem. That does happen connecting the stereo TRS connector from the adapter into both the Bose and the Mackie PA. It does not happen connecting L&R separately into the Roland BA330, so I suspect the adapter here. Maybe I need just a TS plug rather than a TRS, but the Bose does state it takes both. Anyway, I'll go to Radio Shack tomorrow and see if I can't get another adapter.

Nobody said life was going to be easy!

Yes it will take both, but if you are using an adapter that goes from XLR to 1/4-inch, pin 3 of the XLR MUST connect to the tip. This is called an unbalanced adapter.

Gary