So my Marshall blew a fuse the other day. So I took it home and of course I had a power amp tube blown. No big deal. I replaced the tubes and noticed my meter was on MA and not MV. So I switched it over and went on with my business. Marshall amp sounds great. Got to thinking and walked in and checked the voltage on the last amp I put tubes in and it’s off the charts. Switch it back to MA and reads where it should. So I switch my meter to MV and I can’t even get the tubes to come down to the 80MV it suggests. When I bias it to 80 in MA and balance it at 0 it works just fine? Did I screw those tubes up some how. They have maybe an hour on them tops? It’s a fender bassman 300 pro. Amp seems fine. Maybe a little hot but nothing mind blowing for a tube amp. Thanks.