Crate VC50 H power tube question

[jessadr]

When I turn the amp on with the amp in standby the first power tube towards the transformer flashes white for a second. It is the only one. All new tubes. I didn't see it on before I got it. Had no tubes in it. No red plating.
Been on for a few hours tube seems ok. Amp works good. Very little hum.

[Jazz P Bass]

Is it at the base of the tube.
It could be 'heater flash'.
I have seen it in preamp tubes.
Never in a power tube. (yet)

[jessadr]

Yes the base of the tube

[jessadr]

Bad tube. Ordered 8 for 2 amps Groove tube #4 One bad. Something kinda weird. I can turn on the amp then after a while take off standby and when I trurn it off with the standby on the switch stays lit. And if the amp has been on and I turn it on standby the standby switch stays lit about 1/2 brightness. Amp still works good very little hum. I have 2 they both have a little background hum on the over drive channel.

[Jazz P Bass]

The standby indicator is getting voltage from the B+ high voltage rail.
So as long as there is voltage there, the lamp will stay illuminated.
It takes a while to bleed down.

[jessadr]

Thank you. The other amp doesn't do it so I was wondering. Got to tell you everything I know about amps I has gotten from this forum.

[Jazz P Bass]

Well if you are concerned, here is the schematic.
The power supply is on page 2.
There are a number of test point voltages that can be checked.
The dim standby lamp does sound as if something on the high voltage B+ is not correct.

[jessadr]

It sounds good and maybe "if it ain't broke don't fix it' works here.
Thanks everyone. Now getting back to that old 1970 Standell amp