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I get it far enough along so the heaters are wired up, then I do the first power on to make sure they're ok before doing anymore. Wiring up heaters on noval sockets is such a pain, I don't like doing it when there are other wires around. Measure Vf without, then with tubes. Should be high with no load (say 6.7v) but spot on with. I do this before I hook up the HV secondary - I tape off the HV leads, and tape them to the chassis so they don't move or touch anything else.
Before you fire it up with HV the first time, please do the following. This is a short version, there is really more than this to completely measure the amp.
Check the resistance read by your meter by touching the leads to each other. Remember this value.
Check the resistance between the ground of the power plug and the ground of the input jacks. It should be very close to the previous number. If it's not you have a dangerous problem.
Check the resistance between any and all ground points and the spot where the mains ground is connected. It should also be very close to the previous number.
Check that there is no continuity between the HV side of the power - including anode terminals on the sockets - and ground.
If the HV fuse is after the power supply, remove it, hook up your meter to the first filter cap, turn on the amp, measure the B+. You should really use a current limiter or a variac. Turn off the amp and wait until the filter caps are drained.
Put the fuse back in.
Put an 8-ohm dummy load in the speaker jack. Put the tubes in. Measure plate, cathode, and screen voltage on all tubes. Write it down. Measure the voltage at each PS node. Write it down.
I use these these long things to keep my hands out of the amp. I also turn off the amp between measurements. I'm really paranoid about this.
That's just the way I do it. You can do it anyway you want.
Another thing: if the voltages on your tubes look wrong, something is wrong. If the voltages on your tubes look right, well, things may be ok.
Take it step by step, and check it step by step. Have fun.
steven
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