Jack Orman's Super Buffer issue.

[Belt]

I've finished the build with a problem.  I'm testing it with a 9v battery.  My meter shows 7.9v.  I'm getting power through the opamps.  I'm using 2 4558's.  I'm getting power to the 100 ohm resistors.  I'm registering 7.40 on the positive lead on C3 and the lead on C2 that joints with R4.  On the neg lead on C3 and the other lead of C2, I'm registering .04v.  I am also not registering any voltage on R7.  Am I correct in thinking I should just change C2 and C3?

Here's a link to the schematic.  Aron, if there is a problem with me posting this link, please let me know.  I know Jack is a member here, but I don't want to create any issues.  None foreseen though.

http://www.muzique.com/lab/superbuff.htm

Thanks

Don

[Belt]

The neg lead on the C3 and the lead on the output side of C2 seem to "charge" up.  I've tested C3 and it registers 9uF.  When I hook up the battery, it registers around 7v, but then trickles down to 0v slowly.

Any ideas what's up?

[Belt]

anyone?

[MikeH]

Follow the steps here and post your findngs:

http://www.diystompboxes.com/smfforum/index.php?topic=29816.0

[Belt]

Hey Mike, I've kinda went through it that way.  I haven't got pics right now.  But I'll go back and check out the end of the perf.  I'm figuring that the problem is there.... somewhere.

Thanks

Don

[Belt]

I've just swapped the IC's for new ones.

Same result.   

[amz-fx]

I've finished the build with a problem.  I'm testing it with a 9v battery.  My meter shows 7.9v. 

Your battery is dead.

It should measure 9v+ at the power input to the circuit...  slightly less than 9v after the 100 ohm resistor.

If you are positive the battery is okay, then take a pair of cutters and snip the leads on C3 flush with the board. Remove it entirely.  Test the circuit. Does it work? If so, you had C3 in backwards.

regards, Jack

[Belt]

Hey Jack, thanks for the response.  I thought the battery was measuring low.  When I built it, I built it to run on my spare PP2+.  So I didn't add a battery snap, I added a DC jack.  I've hooked it up to the PP2+ which is measuring 9.33v.  Still the same problem.  I'll snip C3.  Should I replace it if that was the problem? 

Thanks again Jack.

Don

[MikeH]

Hey Mike, I've kinda went through it that way.  I haven't got pics right now.  But I'll go back and check out the end of the perf.  I'm figuring that the problem is there.... somewhere.

Thanks

Don

That's good that you did, but it makes it easier for us to help find the problem if we can see you findings too.

[Belt]

Unfortunately, after checking the schematic and the build, I had C3 in correctly.  I took it out anyways along with C2.  I replaced them.  I'm getting the same results.  I'm going to go over it with a fine tooth comb tomorrow.

[amz-fx]

Take the ICs out of the sockets. What are the voltages at pin 8 of the sockets?  They should be 9v.  What is the dc voltage at pins 3 and 5?  Should be 4.5v 

If you do not have these voltages without the ICs in place then you have some wiring problem.

regards, Jack

[Belt]

I'll try that.

[Belt]

woo hoo.

I've got it to pass signal.  NOW the real question.  How can I tell if it's working?  It's not a wet / dry type of circuit.

Thanks for all of your help.

Don