Buffered ABY works best unpowered

[Jmeasterling]

Hi. I'm new. New to building my own pedals anyway. I've modded my guitars since the first, but that's not much circuitry...

I built an aby box following Breja toneworks plans
( https://youtu.be/f7Y8Qm1aOCI ) and built 2 of the buffer circuits mapped out by DIY Guitar Pedals ( https://youtu.be/dMxwT7BT7oE ) I took pictures as it went. It's not the cleanest of installs, but it is my first. The pedal works great, splits channels with no signal loss, runs both channels with no drop out, UNTIL I give the pedal power. It's powered so the LEDs will light telling what channel is in use. without power, it's great, but when powered, if on A or B there's a terrible, pulsing buzz... like a ground fault. Channel Y is silent until I roll the guitar volume on, and same sound... A and B respectively make the hum without volume from the guitar, but Y only hums WITH guitar volume. The breja schematic includes a ground lift, which I put in, but it makes no change when switching it on or off. I ran a 9v battery to the power jack with alligator clips and even tried reversing the positive and negative, in case I had gotten a positive center pin jack, but to no avail. I bought decent quality parts from Mouser and Pedal Parts Plus... Any ideas?

Thanks in advance for glancing at this

[thermionix]

Any way you can upload some pics?  If I'm understanding the concept correctly, the power should only be going to the LEDs and not interacting with the audio signal at all.  It doesn't even need to be grounded to the enclosure.  Sounds like you have a short somewhere, maybe at the foot switch (just a wild guess), and it's putting DC into the audio path.

[Jmeasterling]

https://www.instagram.com/p/BMaxeEZBePU9vB_oPhk4wiruh1Xlc5Wl-ndyLk0/

https://www.instagram.com/p/BMaxV3QBuqikWoRklp2NiYmRh86Zk-mYg1Y1Oo0/

https://www.instagram.com/p/BMX-muAhxHjnVZQd3u0OrzGfqZb3Jp7quApdI40/

[deadastronaut]

you could have used 1 dual opamp for both buffers...

have you drawn a diagram of your build?.

[thermionix]

Wow, I glossed right over the whole "buffered" part!  Ignore my previous post, I was thinking of a passive switcher plus LEDs.  It was very late at night, that's my excuse.

[Jmeasterling]

This is the buffer schematic I used
https://www.instagram.com/p/BMdepNthYcqzHVOKNXNR8RxWlp5ugXCGIbRQdU0/


One buffer replaces the wire from A/B switch to A output
https://www.instagram.com/p/BMdevOIhCpTcBlwrgaqhx1mcBafrdtUI0YC-0s0/


The other buffer replaces this wire from Y switch to output B
https://www.instagram.com/p/BMde0fBhvnoRWkd0T-12q5fy9P0P6HAPnNGnSs0/


This is the pedal wiring diagram, minus the buffers...
https://www.instagram.com/p/BMde3rUBZhkEuMeBF9E2T1tCYlASUDG0CsIOIE0/

None of the images or schematics are my own, just what I used as reference

Images didn't show, so I included the hyperlinks...

Thank you all again for even looking at this with me

[bluebunny]

Images didn't show, so I included the hyperlinks...

The images didn't show because the links you posted point to HTML pages.  They need to point to images: JPG, GIF, PNG, etc.