Hartke LH500 noise issue

[@war]

Hi all!

I took delivery of an LH500 yesterday to pair with my HyDrive 12 cab for a portable rig for smaller gigs.

The head is amazing except that every time I play an A note there is a very audible 'buzzing' noise which goes away if I put some pressure on top of the head.

I figure this is vibration from the cab travelling through the head and rattling the top panel of the LH500 as the noise goes away if the head is not on top of the cab.

So my questions: One, am I right in assuming that this is the likely cause of the problem? Two, anyone have any suggestions as to how to solve the problem without sending the head back where it came from (as the distributor is quite far from me)?

I have tightened the screws attaching the top panel to the rest of the head, but am reluctant to over-tighten them as they may strip.

Thanks for reading!

[craig.p]

I take every opportunity to keep my amps mechanically isolated from vibration. (Over time, vibration can find you an imperfect solder joint or connector that otherwise never would've caused you grief.) I use folded pairs of white athletic socks, two pairs per side, but there are tons of more-elegant solutions on this board from various other players.

[jjk2007]

You could cut a piece of foam to size and set the amp on top of that. Something like memory foam.