Phase 90 with Vibrato and Variable Feedback

[Tom F]

Nothing groundbreaking here, just thought I'd draft a layout of the Phase 90 that facilitates a couple mods.

The first is a switch to kill the dry signal, leaving you with a vibrato sound similar to what you'd get from a univibe. I added a 100nf cap in series with the 150k resistor that gets disconnected by the switch - I had been getting pops whenever I used the bypass switch before, and found that adding the cap there fixed the issue. The second mod is a 50k trimpot instead of the 22k resistor that goes to the script switch. This can be adjusted to give you more or less feedback if desired. Finally, I changed the 47uf electrolytic to 100uf to help filter from the power supply (can't hurt), and I changed the 4.7k resistor in series with the Speed pot to 2.2k to allow faster speeds.

With the exception of a small change I made on the left side of the board (where I fixed problem of the original layout for the phase 90 where a link goes over a wire), this is pretty much verified by me, so it is safe to build. For anyone wanting to take it further, you can do what I did and take the wires for the Speed pot, connect them to a 3PDT footswitch, wire up 2 pots and 2 different coloured LEDs, and have yourself 2 different speed settings that can be toggled by foot.

[vicfiveleven]

Hi, newbie here and a lurker posting for the first time. You guys are amazing thank you for everything here.

Anyway, I already built some of the pedals in this page. Working perfect and sounding amazing. But this is the first time I’ve encountered this issue. I made this pedal and there was no sound when turned on, only when bypassed there is a sound. I double checked and found no accidental solder bridges. What could be the cause?

Thank you in advance for any help and assistance. 😊

[monasfx]

Doublecheck if all components are on the board. With somewhat bigger projects it's easy to overlook a crucial component and especially when the forgotten component is in the signal path its omission can cause your issue, no sound.

[vicfiveleven]

so after finishing some dirt pedals, I finally came back and checked this build. found some cold solder joints and now there’s output. Problem is the volume is very low and there seems to be no phase effect at all. Any ideas? Busted part maybe?