My Onkyo NR-905 Receiver is making my speakers chirping.

What are your digital sources and how is the signal routed (transport to dac)? Does the noise happen with just digital sources, or analog as well? If you're not sure, get a cd/dvd player that has analog rca outs, and plug it into an analog input on your receiver. Let it play for a while and see if it still churps. Also make sure haven't connected any of your sources to a phono input by mistake.

To me, it looks like you have either a digital transmission, or some type of gain related issue. Since you don't know exactly where the problem lies, you need to rule out as much as you can, and force the issue to reveal itself by elimination.

I agree with sfall. You need to determine if you are having the problem with both digital sources and analog. If you tune to FM radio, do you still get the chirp? How about a CD player using the analog L&R RCA inputs? Do you hear the chirp on all inputs, or just one?

Hi Everyone,
I did more research and find out on other forum that Onkyo is known for overheating.  I installed a temporarely fan behind the Onkyo yesterday and that solved the problem. That cooled of the Onkyo and no more chirps.  I have the latest firmware which is 1.08, so it is not the firmware.    These units get so hot that I can even keep my hand on the top of unit for more than 30 seconds.  Gets very hot.   Some have put internal fan in units.  I will just get a fan and adjust the fan to push air from the back and top of the unit.  I Thank You very much for all your feedback.  Much appreciated.