Naughty Fish help, fizzy fuzzy

[irvmuller]

Just finished building the Naughty Fish but I'm having an issue.

Gain knob works just fine. Clear signal is getting through both in bypass and when the pedal is engaged.  However, I'm getting a buzzy/fuzzy sound when I begin to turn up the Peak knob to engage the filter. I'm thinking it may be the Vactrols I installed. I know people have had issues with Vactrols in the past. Does this sound familiar?

I checked all my soldering and everything looks/feels solid and I'm not seeing any bridging. I originally had the volume know installed but took it out to simplify things and hopefully get rid of any complications. The bridge for that is in the back.

I'm checking the volts on the ICs later today when I get my multimeter delivered. If anyone has any tips let me know. I've never done it before.

Any input is helpful. Thanks.

Update: I went ahead and added the values. I underlined the ones which seem most problematic to me. Any input is helpful!

[irvmuller]

I got the multimeter yesterday. The Volts measured pretty much right on. However, I had trouble getting the mV to read correctly. The numbers would just not stop changing. I think it was a trouble with the multimeter which I'm exchanging for a newer, better one. The lower the mV the harder it was to pin them down. So, I'm feeling doubtful there's an issue there and am thinking it is probably the Vactrols. Hopefully, I'll be able to get more solid answers soon. If anyone has any thoughts please let me know.

[danfrank]

Hi,
I've built this project along with a VFE mini mu, which, I think, is the same basic type of effect. The Mini Mu works excellent and does what it should. The NF sound, on the other hand, is glitchy and the filter doesn't engage smoothly. I think the NF circuit is fine but the vactrols I used (Xvive VTL5C3) I don't think are a good match. Maybe the originals would be better in the NF circuit. Either way, I haven't dedicated any time to troubleshooting it and trying different vactrols. Probably what I would do is trace the circuit that drives the vactrols of the Mini Mu, and modify the NF like the MM is around the vactrol portion of the circuit. The MM uses NSL-32, IIRC.

[irvmuller]

I updated the original post with the IC values.

[madbean]

The problem with vactrols a few years ago was specifically for the Macron work-alikes. I've built both the NaughtyFish and the predecessor with genuine VTL5C3 without a problem. But, of course things can go wrong with any build. I haven't seen the ones you are using before (the branded mold on them). Can you point us to where you got them?

[irvmuller]

I originally got it from synthrotek.com but they seem to no longer carry it. I know it is made by Xvive but I'm not sure if it operates the same way. I did find these from sythrotek. Would they work?

https://store.synthrotek.com/VTL5C3-Vactrol-Optocoupler_p_792.html

Otherwise, I know Small Bear is opening up for about 24 hours on Sunday. I can just order the part you originally suggested along with a bunch of other things I need from them.

Any thoughts from the IC readings in the pic above? Thanks for the help.

[danfrank]

Those are the same vactrols that you provided the link for, that I used in my build. Maybe you'll have better luck with them.

[irvmuller]

Great News! I got the Vactrols from Small Bear yesterday and it is now working perfectly! Want to put this out there, if anyone else has a similar problem this worked for me.