need help for debugging a screamer clipping stage

[nonoxxx]

Hello,

I have an old metal zone that I used for experiment for years, and now I am trying to reboxing it , The clipping stage was damaged ( I made a lot of experiments with it, so , unsolder , solder ... and know some parts of the clipping stage are damaged  )
So I decided to replace all the clippings stages by a screamer style one that  was working fine on test board but I made a tagboard and there is something weird , no gain , clean signal.

the voltage are weirds to :

pin1 : 8.30V
pin2 : 8.30V
pin3 : 4.56
pin4 : 0V
pin5 : 1V
pin6 : 1.45V
pin7 : 1.45V
pin8 : 9.20V

I am using only the first opamp so there is nothing connected ton pins  5 ,6,7 .





The blue wire is the input , taken after the buffer of the MT2 (it's connected to the 1uf cap)
red : 9v
black : ground
orange : 4.5v (taken on the mt2 pcb).
the two others wires (blue end green are for te gain pot).

I am testing it by audio probe the opamp pin 1

Thanks

[EBK]

In the future, get some FR-4 boards if you expect to solder-unsolder-solder.

[antonis]

pin1 : 8.30V
pin2 : 8.30V
pin3 : 4.56
pin4 : 0V
pin5 : 1V
pin6 : 1.45V
pin7 : 1.45V
pin8 : 9.20V

ICa out is hitting the positive supply rail, perhaps due to:
<I am using only the first opamp so there is nothing connected ton pins  5 ,6,7 .> 

edit: Your stripboard makes no sense to me..
The picoFarad cap seems to be open - same for poly cap on HPF with gain resistor..

[nonoxxx]

I will check that,
For the tagboard I started with this layout

[antonis]

My bad, didn't notice the 2 row jumper on left of diode pair..

[nonoxxx]

Sorry  for the really bad quality of the picture , the camera on my phone suck

The 8.30 V on the pin 1 and 2 are weird, cause when the ic is removed, and voltage taken on the socket it's fine

[nonoxxx]

I fixed the issue for the first part of the opamp voltages are now corrects . But now the pin 7 is at 9 V lol.
I will try to figure why tomorrow

[EBK]

If you're only using the left side of that chip, you should connect pins 6 and 7 together and connect pin 5 to some voltage between your supply rails.

[nonoxxx]

Oh I got it , the chips was damaged   I swapped for another and it's good now.
@EBK, you think it will be working fine this way?
I am hesitating between a simple buffer like on a ds1 or something like on the Red Snapper OD ( inverting opamp with a 10k and 33 k resitor + a little cap)...

[EBK]

Oh I got it , the chips was damaged   I swapped for another and it's good now.
@EBK, you think it will be working fine this way?

Dunno.  That's why I said "should" instead of "must".   

Preventing noise and reducing unnecessary power consumption are the main reasons for properly terminating that op amp.  Don't know if it also protects the op amp from harm.

Here's some reading material:
https://www.maximintegrated.com/en/app-notes/index.mvp/id/1957

[nonoxxx]

thanks, in fact, the ic was damaged before I put it on this circuit, I forgot that I noticed it some months ago  on a test board  .
the other thing that make the circuit bugging was the fact that I had take the 4.5 on the Jfet switching part of the metal zone and It make  weird things, so I recreated a VB on the tag board from the 9V.
All is fine now (y).
I think I will wire the 2nd part of the opamp as a 10 or 15 db switchable boost stage , and try to add clipping leds , it should sound massive so I will have an OD and a distortion + a paremetric EQ in a box.
I take a look at your ressource on unused opamp so now I think that if the second part is wired as a non inverting 15 db boost , biased correctly , but nothing on the input ( OD mode on my pedal, the output of the first opamp will go to the EQ part of the Metal zone, on the dist mode the opa 1 output will go to the opa2 input ) their will be no noise issue or no damage on the iC , am I right?

guy's , a great thanks for all your replies and help , this forum is really great .