Well, I'm back on this. I ordered a new A30 thinking it was just a bad unit but as soon as I plugged in the first Polk XT20 speaker, the clicking started. Didn't plug anything in for input, just set it to Bluetooth and it clicks.
But here's the thing - I took the A30 to my entertainment center and plugged one of my Polk T600 speakers into it. No clicking, played music beautifully over Bluetooth. Why?!
Thinking maybe it's the speaker, I then plugged the XT20 into the entertainment system. Again, great sound! It only seems to be when I connect the XT20 to the A30 that this happens.
What could possibly be happening here??