I recently finished up a phaser pedal. Upon testing it I found out that the phase effect isn't working. Going through all the steps to troubleshoot, the circuit itself is working and passes signal but the phase effect isn't working. I flipped the four jfet transistors and still nothing. I'm wondering what the voltage reference for the transistors is, the schematics does not have voltages for the vref. I've narrowed down that the transistors aren't switching maybe due to a voltage issue. If anyone has any ideas or knows the vref that could help me out thanks my fellow pedal builders.
Working phaser pedal non working phase effect (xc phase)
- Thread starter ZapAmps
- Start date
benny_profane
Well-known member
Have you used the BIAS trimpot? There’s a pretty narrow range in which it will work.
jimilee
Well-known member
Oh yeah, like slow slow, it’s so easy to miss.
apc42069
Well-known member
dude, I just finished building this and the SAME. EXACT. PROBLEM. I thought I had biased it properly because while turning the trimmer, I heard detected an audible change in my signal.. but no effect.
went back and turned it suuuuuuuuuper slow, first heard a clicking crackle in the signal that changed when rotating C500.. turned the trimmer another millimeter or two, and BAM- phasetown usa!
went back and turned it suuuuuuuuuper slow, first heard a clicking crackle in the signal that changed when rotating C500.. turned the trimmer another millimeter or two, and BAM- phasetown usa!
jimilee
Well-known member
It’s tricky the first time you build one.
sticky1138
Well-known member
I'm working on this one now and I can't find the sweet spot. I'll get a "fixed" phase sound inside about 20% of the trimpot's rotation, but never a modulating phase. Does that sound familiar? I feel like I'm turning the pot in the tiniest increments humanly possible and not finding it.
