Tube amp help-

You may, in all probability, have a shorted rectifier tube. I would test or swap the rectifier before anything else. If it's not the rectifier or the wrong fuse type, then you may have to have it serviced (shorted power supply cap or output transformer).

Don't know if this will help but I was blowing fuses in my Almarro when I turned the amp on immediatley after turning it off. If I let the amp settle for 15 minutes or so, the fuse does not blow.
I'm no engineer but it's probably some kind of inductance problem.
Try turning off your amp with the source still playing so any power caps will drain.
After 15 minutes, remove the fuse to determine if it is melting after turn off or at turn on (probably a good idea to unplug amp from the wall).
This will, at least, give you more info if you decide to contact the mfgr.
Hope this helps...

thanks for all the help, i was able to power down last night and re-start my amp this morning w.o blowing a fuse.

last nite i purchased some Radio Shack type glass fuses which were in the amp in the 1st place. ( my local electronics store only had some Ceramic Littlefuses, which may have been slightly different, which i had been blowing)

so far so good...