SOLVED Paragon - Works with Battery, but not Power Supply

[mmthmj]

Hey folks! I just built a Paragon and everything works when it's on battery power, but nothing works when trying to run on power supply (it does pass signal when neither side is engaged with power supply plugged in).

If I plug the power supply in while the battery is in, it will immediately quit working, but then starts working if I unplug the power.

It seems like this would be related to the power supply wiring, but I'm also wondering if leaving out the Charge Pump causes some issues with the circuit if the battery snap is wired in. I followed the steps in these threads, and neither example included the battery snap.

Another Paragon

I've been meaning to try this for a while, so I finally got around to it: another Paragon build, this time without the charge pump and using carbon comp resistors in the signal path like the original. I had some of those Panasonic film caps at hand, so I threw those in there too. 1S1588 and...

forum.pedalpcb.com

Paragon (KoT)

There are four toggle switches on case (instead of DIP s/w on PCB). Using carbon film resistors and carbon composition resistors like an original KoT. MSPA18 transistor's emitter-base was used for MA856 diode and it sounds really good ! I don't need 18V so charge pump IC isn't on PCB.

forum.pedalpcb.com

Changes I made:
C10 - bumped to 100uF
C21 and C22 - Omitted
Jumpered D14 and D15

If simply removing the battery snap completely will fix the issue, that would be great, but I'm hesitant to try it until I know for sure thats the culprit, since the pedal is functional with a battery.

Here's a picture of the power area. I did reflow a few solder joints with the power jack wiring, but still nothing. Here's a pic of the power area.

Thanks in advance!

 

[spi]

I think you have the post where the battery snap goes and where the power to the board goes reversed.

 

[carlinb17]

Here’s an explanation from beavis audio

Remember how pins 2 and 3 are internally connected inside the jack? So when the plug is not inserted, power flows from the battery, through pins 2 and 3, and on to the circuit board. What happens when you insert the AC adaptor plug? The jumper inside the jack is disconnected, which effectively removes the battery from the circuit and replaces it with the positive signal from the AC adaptor plug:

 

[mmthmj]

Oh wow, that makes complete sense. I was operating under the incorrect assumption that those positive posts were basically interchangeable.

Thanks so much @spi and @carlinb17 !

I'll swap those connections out and confirm when resolved.

 

[mmthmj]

We're in business!! Thanks again everyone!