|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
68.195.144.181
I picked up several Sovtek 12AX7 LPS tubes for sacrificial purposes. Presently I don't play vinyl much and don't want to use up any good tubes in the phono sections of the various Fisher instruments I have. So, I grabbed these at auction for fairly cheap for the purpose of simply loading down the circuit. When I tested them in my Triplett 3423, one side of a couple of tubes pegged the meter! I'm just wondering if using them would cause any damage for the purpose I've stated.
Thanks!
Follow Ups:
As long as the tubes aren't shorted, nothing will be damaged. They're just exhibiting more gain than is typical.
--------------------------
Buy Chinese. Bury freedom.
Sorry not to doubt you, but you did test them at 12AX7 settings?
I would not use greatly imbalanced tubes in phono pre-amp use. Same, in most tuner sections.
Yeah, 12AX7 settings confirmed. I had to double check b/c it whacked the meter. Mind you, my slew of other tubes have never pegged. 10M's, RCA gray and blacks, GE's, Brimars, Japanese tubes, etc have never tested this high. Even JJ's, while high-ish never hit the wall. So, in the end, I'm asking will using them just to "fill the hole" in the phono stage adveresly affect other circuits or damage the unit. What I'm reading is that the tube could eventually let go thereby causing "damage" but that would be much like any of the other tubes going. And if that is going to happen 500+ hours down the line, I could live with that. On the other hand, if it'll go within the first 100 hours b/c of the gross mismatch, then I'd toss it and plug in something else.
I doubt the extra current draw, if any, will damage other parts up or downstream of this 12AX7. However, the audio prolly will suffer.
Just get another 12AX7 (with as close, balanced triode sections as possible). Mark and leave that mis-balanced one in your stock. You maybe able to use it in gain sections where balance is not as issue. Such places, where one triode is doing one function and the other another or none-at-all.
I've tried 12axlps in fisher gear (fisher 400 receiver):
i've found them perfect in v12 and v13;but i have always
selected them carefully.
If you find a tube that measures too low or too high respect
the average ,is generally a rejected tube ;if there is not
a leakege or short it won't damage anything ,it will simply
sound too costipated or too thin
I can deal with a tube with a low side, but if a side pegs the meter....I usually move on to the next tube.
"I can't compete with the dead" (Buck W. 2010)
"$45 gets them out the door tomorrow. $50 gets them out the door yesterday" (Byrd 2016)
I would be concerned about the high side as well. I don't know what would happen specifically but how much juice can the rest of your phono stage tolerate. Seems penny wise and....
Post a Followup:
FAQ |
Post a Message! |
Forgot Password? |
|
||||||||||||||
|
This post is made possible by the generous support of people like you and our sponsors: