Ac30 clone - tremolo effect when goes off

[bluemonk]

When I turn off (or standby) my homebrew AC30 and a note is still sounding, it fades out with a deep tremolo-like effect.
Is it normal or maybe a symptom of something going bad?

Thanks in advance

[trevorus]

I think it's to do with the design of the amp. My newer AC30CC one does it too.

[bluemonk]

Ok, thanks a lot for the info