Naughty Fish only does the down range, not up- schematic reading help needed

[fredwreck]

Yea those are the ones I have, with the blue dot.  And your right the build picture shows the Macrons in it, so that was throwing me for a loop.  I hope this helps other people having a problem.

Thanks for your help Brian.

[midwayfair]

The blue dot is for the supposed VTL5C1 substitute. Theoretically, it should work the same or better than the 5C3 substitute, because it would have a higher total dark resistance (which is limited by a parallel resistor). The important characteristics of making it work right in a Mutron III build wouldn't change, though, so it's not like you just bought the wrong Macron -- the gold dot ones don't work either.

[fredwreck]

Hey.. whatever the Einstein astro physics behind it is.  It still doesnt work.. Get the VTLs!

[taeagan]

I was just about to start another thread with the same basic issue... in my Naughty Fish build, everything seems to be OK in the Range=Down position.  In the Range=Up position I either get no effect, or an auto-wah that is so quiet as to be almost useless.  I fiddled with the gain, sweep, trimmer, and master volume pots in all permutations of the other switches where Range=Up.  I spent a bunch of time with it and I just couldn't get any useful sounds dialed in with Range=Up. 

I'm using the Macron "F" style Optocouplers from Smallbear.  I ordered them a few months ago.  Is the recommendation that I should order the VTL5C3 from another source?  Or should I do some other troubleshooting?  All of my voltages look reasonable as compared to the documentation. 

Thanks.

[fredwreck]

I was just about to start another thread with the same basic issue... in my Naughty Fish build, everything seems to be OK in the Range=Down position.  In the Range=Up position I either get no effect, or an auto-wah that is so quiet as to be almost useless.  I fiddled with the gain, sweep, trimmer, and master volume pots in all permutations of the other switches where Range=Up.  I spent a bunch of time with it and I just couldn't get any useful sounds dialed in with Range=Up. 

I'm using the Macron "F" style Optocouplers from Smallbear.  I ordered them a few months ago.  Is the recommendation that I should order the VTL5C3 from another source?  Or should I do some other troubleshooting?  All of my voltages look reasonable as compared to the documentation. 

Thanks.

Trash those Macrons..goto ebay and search for Xvive Audio VTL5C3! Cabin Global has them for $7.00!

It should be money after that! Let us know if it works after you replace them.

[rrroo]

i made my own LED/LDR combos. first it did not seem to work properly in the filter down mode. Then i noticed that guitar signal was not enough to turn the leds completely of. replaced the 5k trimmer with 25k and now it works!

EDIT: actually I found out that the main problem is that the bias voltage in down mode, defined by resistors r18 and r19 is not optimal. I replaced those with a trimmer working as a voltage divider and now i can really tune in all those crazy funky filter sounds from the pedal.