B&K Dyna Jet 707 tube tester... - Harmony Central Musician Community Forums

SQUAREHEAD · 11-19-2005, 12:07 PM

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

JerryP · 11-19-2005, 01:14 PM

B&K 707 Manual you can download the manual here.
Jerry

SQUAREHEAD · 11-19-2005, 02:37 PM

Quote:

Originally posted by JerryP
B&K 707 Manual 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, 02:43 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, 02:55 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, 03:48 PM

What the heck does that mean tho??

SQUAREHEAD · 11-20-2005, 10:05 AM

^^^^^^^^^^^^^^^

SQUAREHEAD · 11-20-2005, 04:20 PM

bump.

gringo699c · 11-20-2005, 05:40 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, 05:52 PM

go to tonelizards.com and look for his article about tube testers. very informative.

gringo699c · 11-20-2005, 07:15 PM

Why didnt I think of that?
chris

KCA NOS Tubes · 11-23-2005, 06:38 AM

Quote:

Originally posted by SQUAREHEAD
What the heck does that mean tho??

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, 06:55 AM

Quote:

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

11-19-2005, 12:07 PM	#1
SQUAREHEAD Hall of Fame Member Join Date: Aug 2001 Location: Canada Posts: 9,515	B&K Dyna Jet 707 tube tester... 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 __________________ www.fortinamps.com

11-19-2005, 01:14 PM	#2
JerryP Hall of Fame Member Join Date: Mar 2003 Location: Syracuse, NY Posts: 12,638	B&K 707 Manual you can download the manual here. Jerry __________________ FJA Mods Forum and Tech Help FJA Mods Forum FJA Mods Website FJA Mods FJA YouTube Mod Videos

11-19-2005, 02:43 PM	#4
JerryP Hall of Fame Member Join Date: Mar 2003 Location: Syracuse, NY Posts: 12,638	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 __________________ FJA Mods Forum and Tech Help FJA Mods Forum FJA Mods Website FJA Mods FJA YouTube Mod Videos

11-19-2005, 02:55 PM	#5
SQUAREHEAD Hall of Fame Member Join Date: Aug 2001 Location: Canada Posts: 9,515	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 __________________ www.fortinamps.com

11-19-2005, 03:48 PM	#6
SQUAREHEAD Hall of Fame Member Join Date: Aug 2001 Location: Canada Posts: 9,515	What the heck does that mean tho?? __________________ www.fortinamps.com

11-20-2005, 10:05 AM	#7
SQUAREHEAD Hall of Fame Member Join Date: Aug 2001 Location: Canada Posts: 9,515	^^^^^^^^^^^^^^^ __________________ www.fortinamps.com

11-20-2005, 04:20 PM	#8
SQUAREHEAD Hall of Fame Member Join Date: Aug 2001 Location: Canada Posts: 9,515	bump. __________________ www.fortinamps.com

11-20-2005, 05:40 PM	#9
gringo699c Junior Member Join Date: Jan 2004 Posts: 242	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 __________________ http://gringo699c.tripod.com/

11-20-2005, 07:15 PM	#11
gringo699c Junior Member Join Date: Jan 2004 Posts: 242	Why didnt I think of that? chris __________________ http://gringo699c.tripod.com/

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