View Full Version : B&K Dyna Jet 707 tube tester...
SQUAREHEAD
11-19-2005, 11:07 AM
So...
I've used this tester for years...
It actually tells me how any kind of strong power tubes are, but what does it "measure" for 12AX7's?
I know it works, as I use the strongest tested 12AX7's and they SOUND louder... more gain etc.
But what is this thing actually testing in a 12AX7???
Gain? power? output??
Keith:confused:
JerryP
11-19-2005, 12:14 PM
B&K 707 Manual (ftp://bama.sbc.edu/downloads/b&k/707/) you can download the manual here.
Jerry
SQUAREHEAD
11-19-2005, 01:37 PM
Originally posted by JerryP
B&K 707 Manual (ftp://bama.sbc.edu/downloads/b&k/707/) you can download the manual here.
Jerry
Thanx Jerry... but it doesn't work.
I know "how" to work it fine...
I just wondered what it's testing as far as preamp tubes??
I've heard different measurements of 12AX7's... like 1.8 .... or 1600 ... I just want to know which type measurement this 707 tests?
Keith
JerryP
11-19-2005, 01:43 PM
I've had trouble with that site getting manuals too. I figured the manual would also describe the tester and how it tests. There's basically two type of tester as far as I know. One is an emission tester which just tests if the tube has any output and if will amplify, the other measures mutual transconductance and these are the better testers. I'm not really up on tubes. Someone like Mike at KCA or Doug could probably tell you more about what's going on there.
Jerry
SQUAREHEAD
11-19-2005, 01:55 PM
Ahhhh!
Now I'm getting somewhere, Jerry!
Thanx!
It's a mutual transconductance tester. I know that much!! It says that right on it.
Keith
SQUAREHEAD
11-19-2005, 02:48 PM
What the heck does that mean tho??
:confused:
SQUAREHEAD
11-20-2005, 09:05 AM
^^^^^^^^^^^^^^^
SQUAREHEAD
11-20-2005, 03:20 PM
bump.
gringo699c
11-20-2005, 04:40 PM
Info in testers that anyone can understand is here
http://www.tone-lizard.com/
B and K testers are not top of the line testers but will tell you if the tube has a short, gas leak and how much life is left in it.
I have one and its saved me lots of hassles. I dont have to wonder if I need to retube my amp this way.
got it at a yard sale for $35
chris
converge
11-20-2005, 04:52 PM
go to tonelizards.com and look for his article about tube testers. very informative.
gringo699c
11-20-2005, 06:15 PM
Why didnt I think of that?
chris
KCA NOS Tubes
11-23-2005, 05:38 AM
Originally posted by SQUAREHEAD
What the heck does that mean tho??
:confused:
I could give you the formula but what good would that do? Isn't it enough to know that it weeds out bad tubes?;)
Mutual Conductance is roughly equivalent to "gain" which, contrary to "guitar player parlance", doesn't necessarliy have anything to do with overdrive/distortion.
SQUAREHEAD
11-23-2005, 05:55 AM
Originally posted by KCA NOS Tubes
I could give you the formula but what good would that do? Isn't it enough to know that it weeds out bad tubes?;)
Mutual Conductance is roughly equivalent to "gain" which, contrary to "guitar player parlance", doesn't necessarliy have anything to do with overdrive/distortion.
Perfect! It's gain.
That's all I wanted to know, Mike!
Thanx!
Keith