# Fender '57 Custom Twin - Rectifier Question



## Mad Manitoban (Feb 1, 2016)

Recently, I purchased a used Fender '57 Custom Twin 5E8A. It is the earlier model with the brown caps and Weber designed speakers.
I'm not sure what year, but it is in showroom condition.
All 4 preamp tubes are AX7's. This amp has dual 5U4 rectifier tubes.

The Fender manual, and a couple of other sources from the interweb state that one of the rectifier tubes can be removed to increase sag and compression, and reduce negative feedback.
None of the sources, including the Fender manual mention if it should be one or the other.
They only state that one of the rectifier tubes can be pulled.
This leads me to believe that it doesn't matter which tube I pull; I am hesitant to try it.

Does anyone know _for sure_ if it matters which 5U4 to pull?

From the Fender manual:


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## jb welder (Sep 14, 2010)

It does not matter. They are in parallel so there is no difference. Pull whichever you prefer.
The statement about negative feedback is incorrect, the rectifier has nothing to do with it.


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## Mad Manitoban (Feb 1, 2016)

Thanks.


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