My friend with the M75 Lumley has had one amp shut down.
Before that he had some crackling,static sounds,then silence.
We checked all the tubes and they were fine, but the 500MA fuse is toast.
I've been trying to source a schematic or manual for him,but no luck,which seems par for the course.
If anyone has a manual or schematic and could send a copy , please contact me, as I would like to help my friend out and get the music playing again.