i got some jj valves for my jubilee 2558 25/50 watt combo today.
i watched the video of how to do an 800 on eurotubes and the jubilee is the same, they said to set the bias at between 35-40 ma, i tried to check what the plate voltage was but i got a spart twice and it killed my multimeter, the bias on the old valves was about 25ma, when i turn the bias all the way down it goes to 05.4ma, and when i turn it all the way up it only goes upto 29.4, i have the multimeter set on the same setting as they had on the eurotubes video and i have the leads plugged into the ports they said, does anyone know why i cant get the reading up into the 30s and 40s? even setting it at 25ma like the old valves were at had the bias pot thing turned up about 90%
i have been able to set the bias on my dsl401 and get the plate voltage reading on that amp aswell but this is a pain in the arse