PNP positive ground?

[brokenstarguitar]

Got a quick question thats causing me some confusion. Ive been searching, reading, and trying to understand the positive ground with PNP GEs. While I understand that it needs it own isolated power source im unsure if I need to buy a seperate "positive ground" walwart or if a normal pedal plug would work.

I want to use a normal pedal walwart being thats all I have laying around at the monent. If I do need a positive ground plug would this 555 charge pump work and what are the side effects of using such a pump as to say a 7660 or similar dip?

  http://s1300.photobucket.com/user/brokenstarguitar/media/555%20charge%20pump/1_zpsxvphw9zg.gif.html

[smallbearelec]

Positive Ground simply means that the common ground of the pedal wants to see the positive rail of thehe negat sup ply. Is your "pedal wallwart" filtered and regulated? If not, find one that is. Then note whether the plug is center-positive or center-negative. Connect the positive side to the common ground of the effect and the negative side to - 9V (or however the power "hot") lead is labeled.

[PRR]

> a normal pedal walwart being thats all I have laying around

If you have ONE wart powering ONE pedal, then it is + or - ground depending how you wire it.

But next thing you know you have more-than-one pedal. Initially more-than-one wart, but that gets awkward fast, then you wish to combine things. + ground and - ground can not be got from one simple wart.

[brokenstarguitar]

All my pedals on my pedal board are negative ground. So this will need its own plug. Just got to fimd a diagram or understand this alittle better cuz im so not getting this. The board is done using,
http://s1300.photobucket.com/user/brokenstarguitar/media/peppermint%20-%20sun%20face%20fuzz/img_3_zpshthgllcr.gif.html

So i guess what I need to know is if i put this, http://s1300.photobucket.com/user/brokenstarguitar/media/peppermint%20-%20sun%20face%20fuzz/1_zpsqmlsjarc.gif.html

On the same board and connect the power from the sunface to the input power of the 555 schematic, can I wire it like a normal negative ground pedal with the output of the 555 schematic?

[Jdansti]

Here's R.G.'s explanation to add to what PRR said:

Where the positive and negative pins are attached to the incoming DC jack do not matter.

What matters is whether there is a short across the power supply. You cannot connect and have it work properly if
1) you have a single 9V power supply
2) one pedal connects the + side to ground
3) another pedal on the same power supply connnect the - side to ground
all at the same time.

The fact that one pedal connects the positive side to signal ground and the other pedal connects the negative side to its signal ground, and then the signal cable between the two connect the two signal grounds together shorts the power supply. Negative center, positive center, whatever. What matters is whether the power supply is shorted.

[brokenstarguitar]

I understand i cant have negative ground and positive ground in the same chain. What i dont understand is how to wire it all up with the positive ground, in / out jacks, power jack, dpdt stomp, batt clip.

lets forget about everything except wiring this up to work, then ill worry about the chain.

Ive been messing with it and got it to work somewhat but only the volume pot works and I have ALOT of noise. I put a .022 cap across lugs 1 and 2 of the volume and it seems to tame the noise but the other 2 pots still don't work so im pretty positive i have it wired wrong

[MaxPower]

All you have to do is reverse how you normally connect a wall wart to a circuit. Connect the positive output of the wall wart to the circuit's ground. Connect the wall wart's negative connection to the circuit's Vs (Vcc or whatever you want to call it).

http://fuzzcentral.ssguitar.com/fuzzface.php

Look at the PNP and NPN versions of the fuzz face. Look at how the batteries are connected. All you need to do is reverse the power supply.

[induction]

Got a quick question thats causing me some confusion. Ive been searching, reading, and trying to understand the positive ground with PNP GEs. While I understand that it needs it own isolated power source im unsure if I need to buy a seperate "positive ground" walwart or if a normal pedal plug would work.

I want to use a normal pedal walwart being thats all I have laying around at the monent. If I do need a positive ground plug would this 555 charge pump work and what are the side effects of using such a pump as to say a 7660 or similar dip?

  http://s1300.photobucket.com/user/brokenstarguitar/media/555%20charge%20pump/1_zpsxvphw9zg.gif.html

In short, yes, the idea behind the charge pump is to feed it +9V and ground and have it give you -9V to do with as you wish. Then you can daisy chain the positive ground circuit with the rest of your negative ground circuits. Of course, you can also use a dedicated adapter for the circuit. Either approach works. I can't say much about the pros and cons of using a 555 for a charge pump, as I have always used 7660S for this purpose, and have had no complaints.

I understand i cant have negative ground and positive ground in the same chain. What i dont understand is how to wire it all up with the positive ground, in / out jacks, power jack, dpdt stomp, batt clip.

lets forget about everything except wiring this up to work, then ill worry about the chain.

Ive been messing with it and got it to work somewhat but only the volume pot works and I have ALOT of noise. I put a .022 cap across lugs 1 and 2 of the volume and it seems to tame the noise but the other 2 pots still don't work so im pretty positive i have it wired wrong

Agreed, you have problem with your build. It isn't clear at this point whether the fault lies in the power wiring, though. It could be any number of things. We can't tell without more information, like photos and voltages. At this point, it isn't clear whether you are attempting to use the charge pump, a battery, or a dedicated adapter.

Start here, and get back to us.

[brokenstarguitar]

Ok ive uploaded a bunch of pictures. Im going for an Analogman Peppermint fuzz/Sunface with a few mods. Its based off a Fuzz Face but im sure you all know that.

Volume Pot - 250k
Fuzz Pot - 1k
Buzz/Sun Dial - 50k
Q1, the low gain transistor (138 hfe) is a Russian GT308V.
Q2, the high gain transistor (229 hfe) is a 2n404.
I have a 100k trim in front of the 1uf electrolytic cap (swapped for the 2.2uf cap) into the Base of Q1.
A 100k resistor from the Base of Q1 to the Emitter of Q2,
Fuzz pot lug 3 is connected between the 2 on the latter side of the 100k resistor.
A 50k trimpot replaces the 33k resistor in the path of the Collector of Q1 and the Base of Q2.
The other side of the 50k trimpot splits into 2 as one side goes to -9v and the other side to a 1k resistor (swapped for the 470R).
The other side of the 1k resistor splits into 2 with one side going to the .01uf cap that then connects to lug 3 of the volume pot.
The other split end of the 1k resistor goes to a 2.7k resistor (swapped for the 2.2k) in series with lug 3 of the Buzz/Sun Dial.
The Collector of Q2 is attached to lugs 1 and 2 of the Buss/Sun Dial.
Q1s Emitter goes to Ground which also connects lug 1 of the Volume pot and the positive of the 22uf electrolytic, all 3 are gounded.
Lug 1 of the Fuzz pot also connects to the positive of the 22uf electrolytic capacitor, with the negative side on lug 2 of the Fuzz pot.

Ok thats the basic rundown of the board. I built it on a bigger board than i needed in case I needed to add that 555 charge pump. I also have 2 GT308V transistors in the sockets in case something happened, I didnt want to damage the ones meant for this build. The "dot" on the tranny case shows the Emitter side with the Collector in the middle and the Base on the far side of the "dot". Also, Im not putting a stompswitch on this, instead itll be a dpdt toggle. No LED, but i do want a power jack, and battery clip.

http://s1300.photobucket.com/user/brokenstarguitar/library/peppermint%20-%20sun%20face%20fuzz