Amp suddenly goes to half Volume??? Even with new tube...I'm clueless...

[jozLuck]

Have an amp with power problems that just developed. Thought it may be a pre amp tube...nope, maybe a cable..nope.. started with Reverb unit just dying out. Disconnected it as I don't use it much anyway. Low pass filers? Now here is the real clincher: One Fender, did same thing, and had a Carvin, did the same exact thing and the effects loop went out: so got a good wall source with filters, 15 amp and power register to a good conditioner.............. I don't believe in Ghost, anyone have any ideas what cause's this odd situation or what to check...? only notation: can turn the amp off for a few seconds and back on and walla works great for a while...

 

[zzmoore]

Re: Amp suddenly goes to half Volume??? Even with new tube...I'm clueless...

I am confused...are you saying you have identified a wall source problem.?
If not...does this amp have a tube rectifier...have you changed that.?
If this is an amp problem, I would say you need to yank the chassis, and measure all power supply nodes when the volume dives.
best

 

[Johtosotku]

Re: Amp suddenly goes to half Volume??? Even with new tube...I'm clueless...

Have you tried changing all tubes to tubes that you know to work?

 

[zzmoore]

Re: Amp suddenly goes to half Volume??? Even with new tube...I'm clueless...

Have you tried changing all tubes to tubes that you know to work?

^^^^^ Yes.
Re-reading the confusing OP...he does not say anything about power tubes, just pres.
Is it possible he has gone through all of this, and not.......
You also need to look for a cold solder joint that is giving up after the amp hits its operating temp.

 

[Zombiwoof]

Re: Amp suddenly goes to half Volume??? Even with new tube...I'm clueless...

When I had this problem with a new Marshall, it turned out to be a bad power tube. The tech put in a new set of EL34's under warranty, and it went away. Have you checked the power tubes?.

Al

 

[ehdwuld]

Re: Amp suddenly goes to half Volume??? Even with new tube...I'm clueless...

Hmm I had the speakers out of phase with.one another and lost volume once


Had one positive negative and the other negative positive

*(Sent from my durned phone!)*