NPN vs PNP

[Jiberjew]

So, I've been reading up a lot on this, and am some what confident I have this all ready to go. But, I figured I would check here to see If was correct in my thinking. What I'm trying to do is us a PNP transistor, BUT have it work on a negative to ground circuit. What I'm reading is simply flip the transistor so the emitter and collector are on opposite sides. AND flip the EL Caps's. This all seems WAYYYYYY to simple to be true. Am I missing anything, or back to research?? Thanks in advance.

 

[spi]

What circuit are you working with?

I'm not sure exactly what you're asking, but is it how to do something like this? Positive Power for the PNP Fuzzface (muzique.com)

 

[Jiberjew]

What circuit are you working with?

I'm not sure exactly what you're asking, but is it how to do something like this? Positive Power for the PNP Fuzzface (muzique.com)

A few diffrent pedals. Long story short, I’m trying to avoid using 9VDC battery power and use a negative to ground DC power supply. So, I’d like to either change the PNP to NPN transistors to use a negative to ground power supply, or figure out how to use a PNP transistor with a negative ground power supply. I’d like to make it the easiest way possible. For example on the pedals, an old fuzz face, Rangemaster and shatterbox. Hopefully that helps. Thanks!

 

[Harry Klippton]

What's wrong with using a charge pump?

 

[Jiberjew]

What's wrong with using a charge pump?

To be honest, I guess nothing is. I just need to look into how a charge pump works. Haha. I was just curious if what I was reading about flipping the transistors and EL cap’s was all you need to do. But, a charge pump might be the way I need to go, as I’m researching more. I’m still a rookie pedal builder, and I love the old circuits. Wish I could move on to IC’s, but those old pedals sound so good!!! Haha

 

[BuddytheReow]

The best answer you're going to get on flipping the transistor is "it depends". Charge pumps are pretty simple. Here's the power section for the gnat fuzz. You can ignore the top half since it's for the LED.

 

[Jiberjew]

The best answer you're going to get on flipping the transistor is "it depends". Charge pumps are pretty simple. Here's the power section for the gnat fuzz. You can ignore the top half since it's for the LED.

View attachment 80199That’s

Got it. This is probably why I don’t get direct answers when I research this. A charge pump is probably the way to go. I’m sure I can figure out how to implement it to the circuits I want. I did design a NPN Rangemaster, and it sounded great! But, I’d like to build it with a switch that will toggle between a NPN silicon transistor to a PNP germanium transistor. As well as finally build a shatterbox with a negative ground power supply, as I’m always talking about it haha.

 

[Jiberjew]

The best answer you're going to get on flipping the transistor is "it depends". Charge pumps are pretty simple. Here's the power section for the gnat fuzz. You can ignore the top half since it's for the LED.

View attachment 80199

Do you find the TC1044SCPA to be better than the MAX1044? I'm guessing they are pretty much the same chip, just a different manufacturer? Also, probably a dumb question, that the charge pump is obviously prior to the actual circuit, and the negative ground is powering the TC1044SCPA? Looks like the TC1044SCPA does all the work after it gets it's power. If this is the case, should be pretty simple to get this implemented on a PCB design, as it doesnt look like it'll add too much to the circuit. (Not that all those old circuits are too crazy anyhow). And, again, thanks for the help!! I'll order some stuff up and get to bread boarding!

 

[szukalski]

To add my 2c, I have had good success "flipping" circuits for negative ground. Basically, anything with a polarity needs to be reversed.

Generally, the circuits you do this on are not extremely complicated.

Charge pumps are great, but..

 

[Jiberjew]

To add my 2c, I have had good success "flipping" circuits for negative ground. Basically, anything with a polarity needs to be reversed.

Generally, the circuits you do this on are not extremely complicated.

Charge pumps are great, but..

View attachment 80211

This is kind of what I’ve been reading. I do, in fact, like the charge pump. BUT, I would like to do things in the easiest way possible. I am still going to try the charge pump. But I think I’ll try flipping all the polarity sensitive components on a bread board and see what happens haha. Thanks for the advice! Everyone here always gives me great advice and ideas!

 

[spi]

This can help you with wiring a charge pump. Mounted to your switch then you can tap the -9V pad for your circuit.

3PDT Charge Pump Board - PedalPCB.com

 

[Jiberjew]

This can help you with wiring a charge pump. Mounted to your switch then you can tap the -9V pad for your circuit.

3PDT Charge Pump Board - PedalPCB.com

Ohhhhhhhh!!!! Nice. Can’t believe I didn’t bother to look on pedalpcb.com. . Thanks man! I’ll grab a few of those for sure. I’m hellbent on building a shatterbox that works on a negative to ground power supply haha. Not sure why when I have a nice fuzz face and a kewpie from pedalpcb. Guess I’m just on a mission haha. Thanks again!

 

[Feral Feline]

I’ve read bad things about the Max, but not recently.
Nonetheless I’ve got a couple of them I’ve never used; got them from further back before I’d read about Max’s alleged problems.

 

[paulbarrette]

I have done charge pumps (sunface). They fit nicely in the pedal bard with others. I have done battery only (treble booster) that also fit in a pedal board with others. I think it depends on what transistor you want. You could also find decent germanium npn.

Pb

 

[Jiberjew]

I’ve read bad things about the Max, but not recently.
Nonetheless I’ve got a couple of them I’ve never used; got them from further back before I’d read about Max’s alleged problems.

Thanks for the tip!