should I have +9v...

Started by runmikeyrun, September 09, 2007, 12:11:10 AM

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runmikeyrun

on the output pin of a 741?  I can't find anywhere "normal" voltages for a 741 are posted.  This is in '77 OD 250.  I have no noise, signal, hum, anything coming out of it.
Bassist for Foul Spirits
Head tinkerer at Torch Effects
Instagram: @torcheffects

Likes: old motorcycles, old music
Dislikes: old women

burnt fingers

No....

You should not have 9V on the output of a 741.  It sounds like youve got a bit of a soldering problem.  Are you running your power close to the output of the opamp.  You may have a tiny solder bridge. 

Scott
Rock and Roll does not take a vacation!!

www.rockguitarlife.com
My Music

runmikeyrun

that's what i thought.  I've been going over it with the lighted magnifying glass/xacto and found a couple, must be one more in there somewhere.  This is first attempt at vero.  I've been building since 2000 and it is frustrating trying not to get bridges.  I have found a number of them.  I think i'm (dare say it!) going back to perf for my next build.

Thanks for the help, the search continues!
Bassist for Foul Spirits
Head tinkerer at Torch Effects
Instagram: @torcheffects

Likes: old motorcycles, old music
Dislikes: old women

Ronsonic


A DC offset on the output of an opamp is pretty much the symptom when they go bad.

If you've got the usual 4.5 on the noninverting input (pin 3) then I'm inclined to blame the IC.

It might not be you this time.

Ron
http://ronbalesfx.blogspot.com
My Blog of FX, Gear and Amp Services and DIY Info

km-r

or maybe the non-inv input is tied to 9v???

i never use single op-amp in an 8-pin DIL, i always use dual op amps beacuse its the only op-amp config i memorize...

Look at it this way- everyone rags on air guitar here because everyone can play guitar.  If we were on a lawn mower forum, air guitar would be okay and they would ridicule air mowing.