checking voltage on tube mono amps

My Quicksilver mono amps (old 90 watt monos) have not been used for about 17 months. Mike Sanders told to check voltage first before setting-up. He told me, but I have no idea what he said. Any advice on how to do this?

I would call him back and ask him what he means. Other than biasing the tubes and rechecking them to see if they stay within the limits, the amps should be fine.
Agree with Yogiboy. He may have meant bringing them up slowly to 117 VDC with a variac, but they have not sat long enough to warramt that IMO.