Uninvited radio station interference

Need more info. If you could answer a few questions.

Can you hear the two radio stations with the volume control on the preamp turned all the way down?

Does the the radio stations get louder as the volume is increased?

Can you hear the radio stations with the preamp turned off with only the power amps on?

Can you hear the radio stations with the ics disconnected from the power amps inputs?

Are the ics shielded?

Hi and thanks for the response. I can not hear the radio playing when the amp is off. I can hear it when the amp is on and the pre is off, but its so low I wouldn't have noticed it. When the pre is on it is louder and noticeable. When the volume on the pre is turned up, even full, it is not any louder. The Stealth M-7 ic's are "standard double shielded" (from the website).

>>" I can hear it when the amp is on and the pre is off, but its so low I wouldn't have noticed it."<<
>>>>>>>
How close do you live to the Radio transmitting Tower/s?

Not knowing your amps, do they have a metal vented cover over the tubes and electrical components? This cage is an RFI shield, a Faraday cage. Do you have them on the amps?

I assume your speaker cables are short because of the mono amps, is that correct? Long speaker cables will act as an antenna where radio transmitting towers are in close proximity to audio equipment and their ics and speaker cables.
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>>"When the preamp is on it is louder and noticeable. When the volume on the pre is turned up, even full, it is not any louder."<<
>>>>>>>>>

Is this with any source input selected? Disconnect all input source ICs from the preamp, does it make any difference?

What make is your preamp, manufacture? Do you have any covers off? Farady cage.

Do you have any Ferrite Beads, RFI filters? Try them on the power cord of the preamp. RFI can be in your homes electrical wiring, one big antenna, and interring the preamp through the power cord.. Bad thing about Ferrite beads they can effect the sonics of the preamp.

The Stealth M-7 ic's are "standard double shielded" (from the website).

Do you have any other shielded ics you could try?

I previously had the same problem. I suspect your unshielded speaker cable is the prime culprit. Sometimes changing the placement of your equipment can make a difference as well.