Trying to ID the year/model specifically on this one.
How can I tell if it has the tube pre-amp?
Chassis #: 2275-130-UL
Serial #: B008226
Many more photos here: http://imgur.com/a/j5r9z
Images:
Wed, 06/07/2017 - 08:34
#1
armsanddanger
hd130 2275-130-UL
It's got the tube
Hi armsanddanger,
your amp has the phase splitter tube which means it was made 1974 to 77.
Sincerely,
Lars Verholt
Much appreciated! Thanks!
Much appreciated! Thanks!
If you don't mind, and I realize this is kind of a dumb question, but the amp was shipped with the tubes pulled out of the slots for safe shipping. They're all (4) 6CA7 tubes, but only two of them actually say EL34 on them, and those are a bit fatter. The other two simply say 6CA7, and are taller/skinnier. I have to assume it matters which of these go in which slot, in pairs, right?
Never installed tubes myself before, but I just moved 1000 miles from home so I can't take it to my usual amp tech.
(apologies for the redundant picture, but i figured it was worth putting in here. Imgur link above has high res, which makes it easier to read the old stamps)
I would default to...
Hi there,
I would default to putting, say, the two skinny ones on the outside and the two fatter ones in the middle. That gives you one of each tube in each push-pull set.
Cheers,
Lars Verholt
I would also check the bias
I would also check the bias on those four, especially since they are mismatched and obviously different brands. Total draw SHOULD keep you safe but you really should get a quad that at least STARTS out reasonably matched. Mike.