[Amps] AL-572 Negative grid current?

[Scott Manthe]

Thanks to everyone for their suggestions, I really appreciate it!

Well, I don't think it's a tube short, because the behavior is present 
until all the tubes are removed and then, with no tubes, the meters read 
OK. So I either have multiple bad tubes or it's something else.

So here are the new symptoms. When I power the amp up, the grid meters 
pull negative slightly and then slowly move up to zero. Once it get 
close to zero, if I tap on the meter, I can actually get it to stay at zero.

Any ideas?

Thanks,
Scott, N9AA