cmoy no sound

Remove the op amp from the socket, and measure the voltage over the capacitors again. (to begin with).

P.S.

Always be careful when handling the op amp. Touch the ground of the amp with the hand or the instrument you use when inserting it in the socket. En electrostatic discharge can be destructive to its sensitive input stage.

Good, then we can concentrate on simpler things to find the error (or one of the errors).

Is the voltage right at the battery poles when it is switched off?  Do something cause lots of current to be drawn from the the negative supply battery when switched on ( and still with removed op amp). Is any of the components getting warm? (they should in that case).

You must go through the everything on the print board once more. Do all the resistors have the right value. No unwanted connections by loose metal parts?

But perhaps the most common error in a case like this, would have to do with the electrolytic capacitors. First of all check that there is no mixing up of leads around the switch and from the battery. Then try to let the capacitors change place. Any difference?

P.S.

Let us say it this way: No reason to put back the op amp before you have -9V on pin 4, and +9V on pin 8.

The batteries should each show 9V when the amp is switched off, needless to say! You measure always against ground.

Be sure that the batteries are not empty!

To proceed I suggest that we do more simplifications. (feel free not to follow my suggestions, people will attack such problems from different angles).

The switch and the capacitors are not needed to make the thing work.( the capacitors are just giving the battery a helping hand, so to speak), I suggest that you temporarily remove them, to see if you can get the thing up and running. (but keep leads relatively short)

The op amp needs  -9V at pin 4 and +9V at pin 8 (as I said).  See picture. To arrange two 9V batteries to be able to supply these voltages, they are coupled together as on the picture, as you probably already know.  (the important thing is to be aware of orientation of the plus and minus terminals, of course). Olaf

What?! It does not work even with the right voltages supplied to the op amp? Well, keep it this way for a while, it seems at least as though we have eliminated one fault ( since you didn't get the the voltages right earlier).

In my view there is now two possibilites: 1.The op-amp itself is defective (not extremely likely) and 2, even it the schematics are very simple there may be some faulty connection somewhere (even less likely, in view of its simplicity). Will you try another op amp? Or will you once more go through the components and connections on the board?  Your choice. But I can tell you this: The error must be something rather simple and obvious, since  both channels are silent. Olaf

You are sure the headphones are plugged into the correct jack,

don't laugh I've seen it happen

Quote:

Originally Posted by losemoneyg 

......

 

. When I installed the jacks the pins going into the board didn't quite go all the way through. Just trying to narrow down the issue.

 

Follow that lead! Say, if the ground contact of the connector  has no contact, there will be no sound. Also if the two other pins have no contact there will be no sound. (if NO pins has contact, you should be able to remove the whole thing, of course). Switch on your practical sense and you will find a way to  measure to check the contact, I suppose all multimeter instruments have a buzz or beep function!). Olaf

Sorry with the ground off you still hear sound, its very distorted but still there, if there is absolutly no sound ie totaly dead, I'd be looking hard at the power arrangement

cheers

FRED