Hi Ravi,
Lots of good advice from Randyman, Dave, and others. But first, I'll address the power "conditioner" question. No, in my judgement, power conditioners rank right up there with expensive exotic cable in the scam territory. They make absolutely no difference to sound quality, nor should they. Yet naive audiophiles, trying to improve the admittedly flawed illusion of stereo and home theater, will spend hundreds of dollars on power conditioners. Of course, if you believe strongly enough, perhaps you'll hear a difference, just like the gullible townspeople seeing the emperor's new clothes (when he had none).
Any competent engineer designs the power supply of your amp or receiver to filter and transform the AC power from your wall outlet to the appropriate voltages to power the circuits in the amp and receiver. No further power "conditioning" is necessary.
Now, to avoid those large pops (capacitors discharging in amps and receivers) in the future, here's the sequence to follow in powering up or powering down all your gear:
Turn on the AMP or RECEIVER LAST, after you've turned on all your other components, including the subwoofer, which should be the second to last turned on (because it contains a power amplifier).
TURN OFF your RECEIVER FIRST, then your SUBWOOFER, then your TV and all the other components.
If you follow this sequence, you won't have pops again.
I'll deal with your subwoofer hum problems in a later post. I'm certain it's a ground loop.
Regards,
