Trumpet - Tube Roll, first pair of each?

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smitkoku

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Trumpet - Tube Roll, first pair of each?
« on: 8 Feb 2013, 12:23 am »
By "first pair of each", can somebody explain from which end of the chassis the "first pair" would be.  I have a trumpet that sounds really nice with the stock tubes, but I've collected a few RCA black plate 12ax7's and have some Amperex Bugle Boy and Telefunken 12au7's to experiment with.  I just don't know which are the first pairs.  When I start the unit up, the tubes to the front and rear of the unit light up brightest, which only added to my confusion.  The ax's are the same and the au's are the same, so I'm not sure why that would happen.

Help! :scratch:

hagtech

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Re: Trumpet - Tube Roll, first pair of each?
« Reply #1 on: 8 Feb 2013, 06:22 pm »
Each channel is identical.  The "first" tube is the 12AX7 that is closest to the input jacks.  The "pair" would be the first tube for both channels.  I prefer to have them reasonably well matched to keep the EQ the same for both channels.  This is very important for optimal soundstaging.

jh

smitkoku

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Re: Trumpet - Tube Roll, first pair of each?
« Reply #2 on: 8 Feb 2013, 11:59 pm »
Okay, thanks Jim.  That's what I thought, but was just puzzled when I noticed that the first and last set of tubes were glowing brightest so I thought maybe it went from outside to in.  :duh: