# Blues Deluxe Power Section Failure



## Blueskidd96 (Aug 26, 2009)

I've encountered a strange problem with my Fender Blues Deluxe Reissue - it seems as if the power section has been cutting out when I play. When I say "cutting", I mean that there is a significant volume drop. This happens periodically. I know it doesn't have anything to do with the preamp, because when I engage the master volume channel, the 12AX7s distort accordingly with the drive control. Also, the speaker jacks are in properly - feeding the correct impedance to the speaker. The reason why I suspect that the issue lies in the power section - more specifically the power tubes - is that when I set the volume high, and drive the amp hard, the tubes glow brightly. But, when the amp "cuts" out, that glow is greatly diminished. So I think the issue is coming from the power tubes, probably not anything past that, like the power or output transformers. Bad connection, shortage, or even new tubes? 

Help anyone?


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## nonreverb (Sep 19, 2006)

Check the external speaker jack. There is a blade that is normally closed to make the regular jack operational. if this gets weak or dirty, the vibration from the speaker can make it intermittant. It's not the first time hearing or seeing this problem. It's worth looking at.


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## Wild Bill (May 3, 2006)

Blueskidd96 said:


> I've encountered a strange problem with my Fender Blues Deluxe Reissue - it seems as if the power section has been cutting out when I play. When I say "cutting", I mean that there is a significant volume drop. This happens periodically. I know it doesn't have anything to do with the preamp, because when I engage the master volume channel, the 12AX7s distort accordingly with the drive control. Also, the speaker jacks are in properly - feeding the correct impedance to the speaker. The reason why I suspect that the issue lies in the power section - more specifically the power tubes - is that when I set the volume high, and drive the amp hard, the tubes glow brightly. But, when the amp "cuts" out, that glow is greatly diminished. So I think the issue is coming from the power tubes, probably not anything past that, like the power or output transformers. Bad connection, shortage, or even new tubes?
> 
> Help anyone?


One thing you should understand. How brightly the tube glows has nothing to do with how hard it's working! The tube either lights up or it doesn't. If it does it's working. If it doesn't then it's dead.

That's the long and the short of it!

There are a lot of things that can be causing your trouble. It could be output tubes. It could be a filter cap or even a coupler leaking over or trying to short. It could be a resistor failing under load.

It sounds like you need a real tech to dig in and start checking around. Too many possibilities. It's like wondering why your car won't start. Sooner or later somebody's gotta pop the hood!

WB


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