Fifty/Fifty questions

[Rowan]

Hey guys I was recently given a fifty/fifty stereo tube power amp. I was wondering if anybody knew which tubes powered which channel. This amp has an A input and a B input. Also does anyone know how much these sell for? I'm not sure I have any need for it.

http://uploader.ws/upload/200810/boogieback_1.jpg
http://uploader.ws/upload/200810/Boogiefront_2.jpg
http://uploader.ws/upload/200810/boogietubes_3.jpg


Edit: added the URLs because the BBcode isnt working for me.

 

[crane]

The tubes are located this way :

back

I B B A A I---------------
I
I
I
I
I_________a_a__b_b___I

front

a, b : channel controls
A, B: Tubes

 

[Hames]

There seems to be conflicting information regarding the placement:
http://forum.grailtone.com/viewtopic.php?t=24803&highlight=

I don't know what to believe!

 

[crane]

"ABBA" (should say XYYX not to confuse with channels) is a placement of the tubes qhen you have two differents color duets. This way you can mix them to have the same sound on each channel.
But if you want to know wich tube powers wich channel, it's BBAA

 

[GuitarMan]

"ABBA" (should say XYYX not to confuse with channels) is a placement of the tubes qhen you have two differents color duets. This way you can mix them to have the same sound on each channel.
But if you want to know wich tube powers wich channel, it's BBAA

When you do this do you not get extra phonics noise cause in my opinion you should not mix colors on the same channel like say you have a yellow and a blue on one channel you are driving a hotter tube with a colder tube or a colder with a hotter depending on which one is first in the chain now it is ok to run like blues in say channel A and yellows in channel B I am just wondering how that works for you cause I never done it that way and I was taught ( In Collage in electronics engineering ) that it would make low phonics hums and other noises so I just never tried it.