News:

SMF for DIYStompboxes.com!

Main Menu

Tube Pins again

Started by petemoore, May 29, 2004, 07:24:14 PM

Previous topic - Next topic

petemoore

THe last thing that I feel pretty sure about is the Pin 1 of a
 12AX7...A little embarrassed asking this again...
 Facing the bottom of the tubes, looking at the lead pins, Pin 1 is at the bottom on the left of the space which has no pin? No pun intended....sorry for the time it takes to repeatedly answer this one little question...I'm at it again, and can only reference from memory, so I'm confused about it...the socket reversed from the first try...pretty sure everything is right, but still trying to find the problem.
 Still getting 37V on the plates 0v on all the other circuit pins of the tube...it lights using ac or DC adapter...trying to think of something new to tell you...
 :::Question stated as answer:
 I should be seeing close to 'normal' voltages using a bad tube?...ie could it be a bad tube causeing the 0v readings at the Grids and Cathodes?
 I believe the 30VDC adapter I'm using for the non-heater connections of the tube circuitry is rated at 1000Ma.
 I just pulled out the circtuit and ran more tests and lookin it over real good again...Hmmmm
Convention creates following, following creates convention.

sir_modulus

My bad tubes sound well....bad. Your's will sound like nothing. There appears to be a lose connection/short internally if the circuit is a good one. ALWAYS SUSPECT THE CIRCUIT. Check it or have someone check it. Your tube might be desoldered inside. Tube pin numbering(looking from bottom of tube and going right) Gap 1,2,3,4,5,6,7,8,9, Gap.

Hope it helps,

LM 250+

petemoore

Thanks Again..it was in there...I finally found the pinout again but thanks !!!
 I'll double up on my triple checkings...lol :D
Convention creates following, following creates convention.