Crossposted from the Alpha 9500 group:
I had roughly the same experience with my 9500. I bought one Pro-Tek 3CX1500A7
(not the P-for-pulse version) and installed it twice -- briefly. The first time,
both fuses popped. I'd thought this might be because the software glitched; it
had failed to zero the load coil after I powered it up. But I couldn't run any
more experiments that night because I was out of fuses.
After ordering some more fuses, I tried it again. This time, I got a fault 04
(hard Ip fault) and decided I didn't want to use a $7000 amplifier as a tube
tester any more.
So now the Alpha OEM tube is back in and I'm going to try to get my money back.
I'll let the group know how well that goes.