Hi all, I'm new here. If i'm posting in the wrong group then my apologies. I have some questions about the SV20C and using a JHS little black amp box as a volume control in the FX loop. I've played Marshall amps most of my life and i have the SVC20C since a week now. I want to use the JHS pedal as a sort of master volume to control the output of the FX loop into the Output Tube stage. This works generally fine, i can control volume much better and the sound is still great with the normal and treble channel dials cranked up. I've noticed a strange thing though. Occasionally the output volume spontaneously drops to a much lower level and sometimes to almost off. I then have to turn up and down the volume control on the JHS box to restore the volume. It appears to happen randomly and i can't really explain. It almost looks like there is some kind of signal limiting circuit active that randomly tunes the output down. With the FX loop off i have no problems. All cables are brand new and checked. The Questions i have : Did someone else also notice this or similar behaviour ? I this a amp thing or a JHS thing ?. The JHS is a passive box (most likely just an expensive potentiometer in a pretty enclosure) but it seems to behave like there is some kind of an active circuit inside. Anyway i thought i post here to see if i'm doing anything wrong before i call the service desk of the shop where i bought the JHS box. Thanks !