I plugged in my HRM100 recently after a period of non use to discover it is extremely quiet; turning the volume to full raises it to about TV volume levels. Strangely the tone has not suffered much - there is still a fair amount of gain on the OD channel.

It is not in a cab and has been moved around so it is entirely possible that something has been knocked loose or damaged inside, but everything looks fine so I suspect it may be a faulty part or connection. Because there is still gain when the OD is on I am assuming it must be after the gain stage, beyond that though I am at a loss. The valves all look healthy as well.

Does anyone have any thoughts as to what might cause such a problem and what to test?

Obviously, I have put the question to Nik but I though I'd raise it here to see if anyone else had any ideas. Maybe the answers will be helpful to others.

Thanks Boldaslove.

Nik's response was also that it might be the tubes. I don't have any spare, but it's not a problem to get some - and a much easier fix than the other possibilities.

Cheers,