using an audio probe?

[hubble]

hi.  i just made an audio probe for the first time.  does the copper wire around the smaller center wire attach to the metal clip? and the inner wire goes to the capacitor?

also ive been probing and im asuming when i hit a bad point i just resolder that point?  and also, are there specific points that are supposed to be silent?  because everything that is on the board ground is no signal.

thanks in advance for help

[deathbravo]

sorry, i cant help u, i just wanna know how u made it

[Alex C]

Here are two links to diagrams showing how to construct an audio probe:

http://geofex.com/FX_images/audioprb.gif
http://www.diyguitarist.com/PDF_Files/DIY-AudioTester.pdf

does the copper wire around the smaller center wire attach to the metal clip? and the inner wire goes to the capacitor?

If you're using an instrument cable, the copper braid or shielding around the center conductor connects to a metal clip, which then connects to the ground point of the circuit.  The center conductor connects to one lead of the capacitor, and the other capacitor lead connects to a clip that is used for testing various points in the circuit.

also ive been probing and im asuming when i hit a bad point i just resolder that point?

A "bad point," or a point at which you're getting little or no signal, usually indicates a problem earlier in the signal path.  A bad solder joint is a possibility, but it could be due to miswiring or a solder bridge, etc.

and also, are there specific points that are supposed to be silent?  because everything that is on the board ground is no signal.

Ground is the point in the circuit which is at 0V, so you shouldn't have any signal at ground. 

What circuit is it?
Hope this helps, and good luck getting it working!

-Alex

[Peter Snowberg]

Welcome to the forum.  

Here's Paul Marossy's: http://www.diyguitarist.com/PDF_Files/DIY-AudioTester.pdf
And here's R.G.'s: http://www.geofex.com/FX_images/audioprb.gif

Yes, the shield wire gets attached to a clip which is then connected to the effect ground and the center wire connects to the cap which this connects to the point of the probe.

It's one of the world's best tools for debugging audio electronics.

===========================
Hehehe, Alex got it before I did. 

[deathbravo]

why not u use a oscilloscope?

[Peter Snowberg]

Scopes are great, but not everybody has one. Additionally, with an audio probe you can listen while you trace. With a scope you need to look back and forth as you follow the signal. The probe is also good for allowing you to judge the realitive level of amplification at different points in the circuit without having to do any thinking.

[$uperpuma]

best $1.23 I ever spent...

[hubble]

ok thanks for the help.  i hooked it up correctly, and found a handful of bad points.  the wiring is correct, so that means it must be bad solder joints?  im a beginner at this, but if the emitter of q1 is quiet/no signal then would the base need to be resoldered?

btw its the tyco octavia project from ggg
there are no solder bridges that i can tell, im 100% sure the wiring is correct.  when plugged up the pedal bypasses but when engaged theres no signal.  i did get it to make a crushing/distortion sound for a very short second, but not anymore.

[Seljer]

Might be a bad solder joint, might be a fried component, might be a wrongly oriented component....theres tons of things that can go wrong

[gaussmarkov]

yes, welcome to the forum! 

given the title of this thread, i suggest you start a new thread asking for help debugging your circuit.  be sure to follow the procedures outlined in the top thread What to do when it doesn't work and to read the Debugging Page and its links.  that will help us help you! 

[hubble]

thanks, ill post a new thread soon with more details!

[choklitlove]

there's also a good graphic and some good info on the probe here: http://storm-software.co.yu/diy/index.php?project=stuff