[chenao72]

Hi Brach,

Thanks for your repply. I am glad my relatively lengthy descriptions help. It comes natural as my background is in engineering, but not in electrical engineering, mind you. So it happens that I started playing guitar late in life, as a hobbie, and now I am exploring pedal assembling and starting to read about pedal electronics and modification.

Since I have several SNL-32SR2A, I will find 4 of the most similar in the batch and give them a try. To simplify trying different optocouplers, I will remove the ones currently installed in the PCBs (main and stereo) and install sockets in their place.

Any thoughts or suggestions will be most welcomed.

Regards,

Carlos.

[chenao72]

Hi Brach,

Thanks you very much for your prompt reply. Here is the info you requested:

1) The stereo kit I recieved contained 2 pairs of LDRs, and the main Kit came with none.

2) All 7 jumpers (Cal-1… Cal-7) were installed when running the stereo routine (both times I ran it), and once the routine was done I pull them out and put Jumpers J5 and J6 back in place.

3) I am sorry, but I do not have the bags the LDRs came in. They went into the trash last week. What I can tell you is that there were 2 small bags, each containing one pair of LDRs, each pair consisting of a marked LDR and a non-marked one. These bags came as part of the stereo kit, stapled to one another.

4) I could try the poster putty, but I think the optocouplers are well sealed, as I used thick nail polish and built the seal using several layers to completely fill any gap. Additionally, when I was measuring the LDRs while having the LEDs powered at bias voltage, I tried measuring the resistance with my workbench spotlight on and off and I didn’t detect any difference in the measures. I will send you pictures of the optocoupler ends so you can see and let me know if you still think the seal is not what it should.

An additional question for you. If I were to replace the optocouplers using commercially available ones, would any of these models from Advanced Photonics work? :
* NSL-32
* NSL-32SR2
* NSL-32SR2S
* NSL-32SR3

I have about 10 of each and I can send you the satasheets for you to take a look.

How would one go about making pairs for each channel? what would the tolerance be?

Thanks again for your help.

Carlos H.

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