Tayda Tone Bender PNP with 3PDT PCB

[makisushi]

Ah!
Another week, another (failed) pedal! I was on a good streak with my last builds, and I thought this one would be easy, but oh! Was I wrong?


So I built the Tayda Tone Bender PNP version (with 2N3906 for now), BUT I also used this 3PDT breakout PCB from pcbway, which works great on my other pedals. Now, I don't think I fully understand this whole 9v+ and 9v- thing because the first time I plugged the pedal in with a wall adapter: POW! Blew a cap… Replaced the cap, used a 9v battery, and this is where it gets complicated:

1. The 9v battery is wired the right way on the 5.5mm x 2.1mm DC male adapter, which means the center is POSITIVE and the outer is NEGATIVE.
2. On the pedal, the center pin is "NEGATIVE" (black wire), and the outer is "POSITIVE" (red wire). So right there, the polarity is reversed, but
3. The pedal does work like that.
4. However, the LED doesn’t work on 3PDT breakout, and I get a reversed voltage reading with V- on the positive lead and GND on the COM lead.
5. So where exactly is the ground going? Why is just not named the other way around? Do I just flip the LED on the breakout PCB, or does that mean that all my “ground” (black wire) from the 3PDT PCB is actually feeding the hot signal? Since I don’t want to blow more caps, how do I fix this the right way, the first time?

 

[makisushi]

So I did reverse the polarity of the battery AND the polarity from the breakout to the fuzz.

AND NOW:
I will name it the "Skrillex Fuzzstep"

 

[BrainDrain]

For positive ground circuits the LED will be reversed. Long leg to “positive ground” (black) and short leg to “negative 9v” (red)

With “positive ground” circuits you’re just reversing the positive and negative going into the pedal. I can’t tell from the pics if this pcb is specifically laid out for positive ground but usually it requires reversing any polarized components too. So for example, electrolytic capacitors will be reversed.

The easiest way for me to think about is the black wire is now positive and the red wire is now negative. It’s called “positive ground” because the 9v is now -9v and 0 is “more positive” than -9. There’s probably someone else on here who can explain it much better but that’s the basic idea.