Make sure you have a good ground for the changer. There is a possibility that one of your grounds has some resistance in it causing any static buildup to discharge thru the amp.

I recently did a Magnasonic that had the Amp142 and the tuner was a CR745AA. Sams 404-9

This store is in Houston. It's an awesome place to just wander around and see everything they have. I got my HP8640B from there. We even got our Bunn 3 pot commercial coffee maker there for $60.

Tell us about that tuner change. I cant imagine why they'd do that unless the design had a problem with adjacent-channel interference and instead of improving selectivity, they just decreased sensitivity. Chris Campbell It's the 6401 chassis that needs this modification. For some reason they are us...

Glad to be back!. Hey I uploaded the Magnavox factory service and alignment manual for the 7001 thru 7006 FM MPX adapter.

Looks like I need to read thru this thread a few times as in my opinion my imperial amp is also lacking in bass. I have completely rebuilt it. I did find the 6401 series tuner had a modification by magnavox that dropped the sensitivity of the FM. I ended up converting it back to what was in the 54 s...