static?

[packagebear]

I'm having a bit of an issue with my 8pack of pres.

When i touch the gain knob on a few of my A12's i get a burst of static through the output of the pre. If i continue to touch the knob the static goes away. But it I touch it again a minute or so it seems to "recharge" and produce static again.

I've only noticed this at one location thus far.
I'm not quite a noob but I;m not quite sure where to start with troubleshooting.

any ideas would be appreciated.

thanks
kris