Infamous engine squeal at idle

[webdr]

I have the squeal...

After reading up, I thought it was the DISA valve. Took it out (was relatively clean and not stuck) cleaned it and reinstalled but squeal at idle was still there.
Ive realized it:
a) is constant when the ac is on at idle
b) very faintly present or not at all w/ ac off at idle
c) if ac is off and the squeal is not present, a quick pop of the throttle will make it happen for a split second then dissapear.

Its hard for me to diagnose the area its coming from but Im pretty sure its not the DISA valve area, more towards the front.

Im just hoping its not the ac compressor or alternator.
May be a tensioner? Or old belts?
I inherited this 02 so I dont know when the belts were last changed.

thanks
Matt