Retube - Dimmed tubes question - Express

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1esotericguy

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I just did a tube swap on my Express 5:50. I noticed something odd and wanted to see if anyone else can explain or verify it.

The preamp tubes in V2 and V5 don't glow much at all. Like 5% of the glow when compared to the other tubes. I swapped in the original tubes in the same spots and they glow the same. You can barely see it.

The amp sounds fine. Nothing odd there.
The tube task chart in the manual says that the V2=1st gain stage clean and 2nd Stage OD; V5=Reverb

Has anyone noticed this in their amp or can verify that this is just the design of the circuit?
 
A few of the Russian tubes barely light up and is common and does not effect them whatsoever. I cant remember which brand right now...
 
I was wondering the same thing about the preamp tubes. In my Express 5-50 V1 and V5 don't glow at all while V2, V3, V4 are glowing away merrily. Tried swapping V1 and V5 with new tubes and they are the same. I can't see a glimmer of light from them at all and even darkened the room. Seems strange but amp working OK.
 
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