Fender Twin - time to replace tubes?

[fatorangecat]

Hi i hope this question hasn't already been posted, but here goes:
i'm using a fender twin reverb. Recently, the red power light gets dim after playing for about an hour or so. It seems like there is a slight loss of power/volume, but it's largely imperceptible. Does this mean I need to replace the tubes? I read a post that said if the tubes are blue, it's time to replace, but they still seem orange to me. Also, I've been using the amp for about two years -- how often does one rebias/change tubes?

If it's any help, i bought it new (black face reissue) and it's using groove tubes.

thanks for any help,
tim

 

[Middleman]

Could be the tubes but I would bet that you have a some leaky caps that need replacement. Take it to the shop and have them check it out. Unless you have experience in electronics I would not try to repair this yourself.

 

[pchorman]

That red light ought to be an indicator of line voltage, either AC line voltage before the transformer or DC (rectified) after it. If it dims, something is heavily loading down your power supply to affect the voltage regulation. Alternatively, some other heavy electrical load in your home coincidently kicks in from time to time and pulls the line voltage down, like a central air conditioner. Does this happen on any other circuit in the house? Is there a pattern to it? When it happens is it sudden or gradual, a one-time deal or periodic?

 

[fatorangecat]

Thanks for the help

As for the dimming light, it occurs on any outlet, in my house, in our rehearsal place, and during my last gig. I'm taking it in for fixing today -- if they can find the cause, I'll post it (as a FYI)

thanks again

--tim