rember one thing, EQ's (little known fact) are only made (its main goal) to cut levels not boost, turning its gain down and not boosting your 400khz and up freqs. will and probaly would have removed most of your noise before doing anything else. one important thing to do most techs in my idustry dont get or understand is case grounding all componets. that means running a wire from case screw of the reciver to case screw of your amps, computers, eq's etc