pedalpcb Valhalla not working right

[whomeno]

I built the valhalla. works good except for this problem. after I engage the pedal, then disengage I have no pass through. If I keep switching it on and off, pass through comes back. I might have to do this 3 to 10 times of on and off before I get it back. Had the problem posted on there form but no answer. I tried another stomp switch still the same. what could be the cause of this?

[antonis]

Check white wires joints on PCB..
(they seem to be a bit of mess..)

If not, something might happen around L7812 regulator..
(IMHO,as it is, it's a bad design - for lack of both input capacitor and reverse polarity regulator shunt/bypass diode..)

[whomeno]

Cleaned wiring up. did not make a deference. I hate buffered effects. guess i might just have to live with the way it is.
Thanks

[whomeno]

This my be a dumb question, but is there a way to take it from buffered to true bypass?

[Ice-9]

I would try a new fotswitch, if it works after so many presses then it is likely the contacts in the switch or as said above bad wiring.

[r080]

The way the buffered bypass works is one side of the switch does the LED, and the other side of the switch selects whether the buffer out or the PCB out is what gets sent to the output jack. Yes, you could convert it to true bypass by using the input and the pcbout pads and find a true bypass wiring diagram. However, there is nothing about this that looks like the buffered bypass is causing the problem. If you convert it to true bypass, it is unlikely to fix the underlying problem.

One option, which you see in Pete Cornish builds, is to double up the signal part of the switch. You can see that in Aion's tracings of some pedals:

https://aionfx.com/app/files/2020/09/cornish-st2-inside.jpg
https://aionfx.com/app/files/2020/09/cornish-st2-main-pcb-removed.jpg
https://i.imgur.com/vYDAx9X.jpeg

I have never done this before, but it would be a quick way to give your switch some redundancy. If it fixes it, it was easy to do. If not, you might need yet another switch.

[whomeno]

tried 2 new foot switches re-soldered wiring to the foot switch. still the same.

[antonis]

I insist for op-amps latch-up..
(possibly due to both  power supplies not established simultaneously with or before input signal applied..)

[whomeno]

thanks for all the help

[Slowpoke101]

This probably will make no difference at all but...

Some of your 1uF and 2u2 electrolytic caps are installed with the wrong polarity.
The 1uF at the output of the buffer may be upset with that situation but I think it is installed correctly.
Have a closer look and see which ones are wrong, re-install them and see if things improve.

[antonis]

If it's possible, add a 100 - 470nF cap between IN & GND and a 10 - 22μF cap between OUT & GND of LM2940..

[whomeno]

the pcb is labeled different the the layout. don't know why but it is. I thought them same thing, pulled those caps to make sure.

[whomeno]

went over the switch wires again with soldering iron. works fine now must have been a bad solder joint.
thanks for all the help

[duck_arse]

a present on your birthday?

[whomeno]

duck_arse
Thanks