Hi there, guys 

I’m new to the forum and new to valve amps. In fact, I’ve just purchased my first valve amp: a brand new JCM 800 2203 reissue.

Running through a 1960av and a Rivera Rock Crusher attenuator and it sounds awesome - except for these damn so called ghost notes (just learned about them) that only happen when I set the master volume at higher values (above 6.5 or 7). It also only seems audible in higher pitches around the 12 fret.

Reading a lot about filter caps and stuff. But it’s a brand new amp and I still have warranty. So that’s not the case for trying to fix it myself.

My question is: should I assume it’s “normal” and keep my amp? If that’s the case, how can I crank it (and get that  beautiful power section overdrive) and minimize those annoying ghost notes? Is electric grounding improvement / adding a power filter of any good?

Or you guys think I should go to Marshall assistance and ask for a replacement?

Thank you very much,

Any help appreciated,