Hi,
Was hoping someone out there has experience with using RFI/EMI filters and if they're useful in eliminating the infamous amp hum. I'm on a crappy old squier strat, with a Marshall Valvestate series, 265. Been looking around the net a bit and have heard the hum being attributed to all kinds of crap; pickups, sound loops, electrical pollution, etc. A $50 RFI/EMI filter such as Furman even worth it? I've seen some noise cancellors out there that are like a pedal, but have heard that they hurt the highs-no good. Also looked into a humbucker to fit into a single coil neck slot for the strat, but seems kind of self-defeating to the strat sound. Anyone have any take on this?

No experience with the Furman filters. If you're considering one of these types of units, make sure it's compatible with a guitar signal. Some, such as Ebtech Hum Eliminator, are designed to work only with line level signals.

When I was playing high gain amps, the only practical solution I found was the BOSS NS-50 Stereo Noise Suppressor half rack unit. Before that, I tried a variety of conventional noise gates... these are prone to chirping & chattering... plus, when you set them up to deal with your noisiest signal, they make your cleaner, low gain stuff basically unusable. Then I tried several versions of the Rocktron Hush units - awful. Totally destroyed the high end response. The BOSS does none of that. There will always be some compromise with noise reduction units, but the BOSS remains truer to base tone & dynamics than anything else I've found.

Since I don't use high gain amps anymore, I get most of my noise from pedals. So I use the BOSS NS-2 pedal, which is based on the same circuitry as the half rack unit. I play traditional single coils (not noiseless), & my rig is pretty quiet, even if I'm using a ton of gain from pedals.

Even if you do go with a noise reduction unit, make sure that your guitar is properly shielded.

I've seen used NS-50's go for as low as 40 bucks, which is a stupidly good deal.