Here is another suggestion - since I just blew a fuse in my VP-100i. DON'T stick the common (ground) probe in the well on the same side of the amp as the hot probe. Use the common on the opposite side of the amp. That way you won't have to trim the probe. Also you will avoid a short. If you touch, or get real close for that matter, to the common with the hot, the probes can arc and blow a fuse. I just did that. How stupid of me to not see that the probe wells were designed so that it would be difficult if not impossible to get a reading with both probes on the same side of the amp. If you use the common on the opposite side, all is well - and you won't blow a fuse.
Cayin A50t biasing problem
I recently purchased this amp on a'gon and having trouble getting it bias. When try to measure the bias I get no reading on any of the pots. When I try to raise the bias, the travel of the pot is very small like 3/4 of a turn. Is this normal. I have had many tube amps so I think I understand the process. I can't believe I have 4 bad pots nor 4 bad tubes. What give anyone?