@Clockworkmike - i go ferrite rings on every cable and EMI filters in the amp inputs and this is just to minimize the interference from the local 95.1 FM radio transmitter 1/2 mile up the hill from our house.
Without those items, the radio station plays loudly through the amps.
Also, in most clubs down here, i had a LOT of problems with cell phone conversations inside the club being broad ast out over my amp and, in two venues, the electric games that are on the tables was coming through our PA. We used a power conditioner on the PA, but we could NOT stop the video games from broadcasting through the PA until we installed ferrie choke beads on the PA speaker cables themselves!!!!
@Don O fixed my 1993 Marshall Valvestate Bi-Chorus 200 with one of these...

Without those items, the radio station plays loudly through the amps.
Also, in most clubs down here, i had a LOT of problems with cell phone conversations inside the club being broad ast out over my amp and, in two venues, the electric games that are on the tables was coming through our PA. We used a power conditioner on the PA, but we could NOT stop the video games from broadcasting through the PA until we installed ferrie choke beads on the PA speaker cables themselves!!!!
@Don O fixed my 1993 Marshall Valvestate Bi-Chorus 200 with one of these...
























