Hi!I'm looking for some advice regarding my aging NAD C370. I've noticed recently that the volume sometimes dips for no apparent reason while watching TV / listening to music / gaming and am starting to imagine that I hear some sounds being distorted while listening to certain CDs that I don't notice on other equipment. I can also hear the distortion through headphones attached to the NAD, so it's not the speakers. Anyway.. - Can anyone offer any advice on what might be causing the issues I'm having?- Is there a chance it just needs a good dusting? It's never been opened.- Is it worth having the AMP repaired or would it be more cost effective to buy a new amp?- Does anyone have a suggestion for a suitable replacement? I have a Marantz CD6005 and a pair of Monitor Audio Silver 8is. I mainly use this system for music (electronic and jazz mostly), but also need inputs for TV and consoles. I wouldn't want to spend much more that £300. Any advice is appreciated!Thanks.