290 question

[WEGjr]

Hello everyone! I'm new to this forum, but a longtime
owner of a Triaxis.
Recently got a 290 off of ebay, and it seems to be
working properly, except that it's a little crackle-y
sounding w/ some hiss. And input A seems to be
a little inconsistent signal-wise. Is this a sign the
tubes need to be changed? The tubes do have some
"wear" or "burn marks" on them. And one final
question-Am I to understand that I must open up
the 290 to replace the 12ax7's? I don't see them
in the back. Just want make sure that's a job I
can do without taking it to a tech. Just got my Triaxis
back from Boogie for repairs, and don't wish to
be w/out for another month! Thanks in advance for
your replies!

 

[Boogiebabies]

You can retuebe that thing yourself. Just unscrew the top and replace the two quads with matching tubes. The pre's are just as easy. The output will be pretty close with a new matched quad of tubes, but remember that unless you have perfectly matched quad 12AX7's in the preamp and your volume knobs are the identical taper your channels should be pretty close to having a perfect balance. I just did a a Simul 2:95 and it worked out perfectly and was nice and loud with great channel balance.

 

[WEGjr]

Thanks for the reply! Do you think the hum/hiss/crackle
and inconsistent volume changes on channel A is a sign
the tubes are on the decline? The tubes do have some
burn/wear marks on them...I'll probably get a retube kit
from Eurotubes. I retubed my Triaxis w/ a set from
Eurotubes and they are awesome! Thanks for the reply!