I recently had a similar problem. My system is on a dedicated line. I was running non-audio gear--TV, DVD player and equipment lamp--from a separate socket on a separate line. This stuff plugged into a switched mass-market power strip. The power strip's cord was back of my rack, running past my audio AC cabling. When I unplugged the strip, the music sounded clearer and livelier.
I had to find a way to keep the ancillary gear's power bar from affecting my audio. What I did was use some leftover parts to make up an outlet box. I used Belden 12-gauge shielded cable, about $20 worth, a $10 hospital-grade Leviton outlet and a metal outlet box.
Maybe a plastic box would be better, but the plugged-or-unplugged sound test, using this box, shows no appreciable difference. My conclusion is that it is the shielding on the cable to the box that really makes the difference. An unshielded AC cable running past my audio gear's power cords has an audible effect. This is true even if I run the wires so they all cross at right angles.
Jferreir, if you were nearby I could lend you this wonder wire and you could try it out. You could run an extension cord to a separate outlet for this if you wanted, but it might not make much difference if the separate outlet weren't on a separate circuit. Anyway the point is moot because you're probably not nearby. I'm in Montreal myself.
So my point is that shielded wire to the outlet is a Good Thing, and you can do it within your budget.
I have one more point. A shielded wire to your outlet strip will keep interference downstream of the socket to a minimum. However If you want to keep ancillary gear on the same outlet as your music system from affecting your audio by feeding grunge back into the *upstream* AC, you need to isolate something. Either the audio gear or the ancillary gear.
The ancillary gear isn't picky about isolation quality and it doesn't draw much power, so given your budget I would isolate that. You should be able to find an isolation transformer ( 120V in, 120V out ) rated at about 500 VA on eBay at a price that keeps the whole project within budget. Plug the tranny into the wall, plug your new power bar into that and I think you will solve the problem.
Note that isolating the audio gear would do the same thing and it would very probably improve the system's sound a lot into the bargain. However you'd need a really big transformer, more than your budget allows at this point.
I had to find a way to keep the ancillary gear's power bar from affecting my audio. What I did was use some leftover parts to make up an outlet box. I used Belden 12-gauge shielded cable, about $20 worth, a $10 hospital-grade Leviton outlet and a metal outlet box.
Maybe a plastic box would be better, but the plugged-or-unplugged sound test, using this box, shows no appreciable difference. My conclusion is that it is the shielding on the cable to the box that really makes the difference. An unshielded AC cable running past my audio gear's power cords has an audible effect. This is true even if I run the wires so they all cross at right angles.
Jferreir, if you were nearby I could lend you this wonder wire and you could try it out. You could run an extension cord to a separate outlet for this if you wanted, but it might not make much difference if the separate outlet weren't on a separate circuit. Anyway the point is moot because you're probably not nearby. I'm in Montreal myself.
So my point is that shielded wire to the outlet is a Good Thing, and you can do it within your budget.
I have one more point. A shielded wire to your outlet strip will keep interference downstream of the socket to a minimum. However If you want to keep ancillary gear on the same outlet as your music system from affecting your audio by feeding grunge back into the *upstream* AC, you need to isolate something. Either the audio gear or the ancillary gear.
The ancillary gear isn't picky about isolation quality and it doesn't draw much power, so given your budget I would isolate that. You should be able to find an isolation transformer ( 120V in, 120V out ) rated at about 500 VA on eBay at a price that keeps the whole project within budget. Plug the tranny into the wall, plug your new power bar into that and I think you will solve the problem.
Note that isolating the audio gear would do the same thing and it would very probably improve the system's sound a lot into the bargain. However you'd need a really big transformer, more than your budget allows at this point.