Paired tubes in a 50/50

[srommes]

Ok, I tried the search function and read through 20 pages without finding an answer to my question. Which 6L6's are paired in the 50/50 poweramp? Is it the two left, two right or the two inside, two outside? Thanks in advance!

 

[crane]

Tubes are like AABB, A & B for each channel.

http://forum.grailtone.com/viewtopic.php?f=5&t=24803

 

[srommes]

Great. Thanks!

 

[petejt]

Is it possible to mix matched pairs in the 50/50? e.g. a pair of EL34s and a pair of 6L6s?

 

[crane]

The 50/50 doesn't support EL34.
I think it's possible in the 2:50, but either the 6L6 must be selected for the EL34 bias, either the EL34 selected for the 6L6 bias.

 

[elvis]

I wouldn't. One or the other will be biased incorrectly. If you choose 6L6 selected for EL34 bias, or vice-versa (if either such thing is possible), then those tubes are WAY out of spec, and will likely not perform very well.

It is possible a decent tech could modify the bias so that one side is properly set up for 6L6 and the other EL34. If that is possible, then it may also be possible to add a second bias switch so that each channel could have its own bias select. Depends on how interrelated the bias circuits are.