Breadboarding -9v?

[CheapSuitG]

Here is my question of the day.

New to all of this, learning bread boarding and want to try a fuzz face, what is the -9v on the top? How do I go about doing that?

 

[Robert]

Either reverse your power leads connecting to the breadboard (positive is now ground) or use a charge pump.

 

[CheapSuitG]

Either reverse your power leads connecting to the breadboard (positive is now ground) or use a charge pump.

View attachment 86898

So what typically is the ground is now the positive.


What is the reason behind this? Just trying to wrap my head around it.

 

[JTEX]

Circuits with PNP transistors usually use a positive ground because PNPs are biased the opposite way of NPNs: their base and collector need to be more negative than the emitter. Since the emitter is usually common between the input and output, we call that node the ground: the common potential to which all voltages in the circuit are referenced. A ground does not have to be negative, that is not a hard rule but just a convention. Negative ground simply happens to be more common these days, when NPN transistors are more frequently used than PNP.

 

[CheapSuitG]

Got it.

So I can use PNP germaniums with this, interesting......

Circuits with PNP transistors usually use a positive ground because PNPs are biased the opposite way of NPNs: their base and collector need to be more negative than the emitter. Since the emitter is usually common between the input and output, we call that node the ground: the common potential to which all voltages in the circuit are referenced. A ground does not have to be negative, that is not a hard rule but just a convention. Negative ground simply happens to be more common these days, when NPN transistors are more frequently used than PNP.

 

[Nostradoomus]

The original uses pnp (ac128), you can flip the polarity of the 2 electro caps and use NPN with a normal centre negative supply if you want. Decent PNP GE transistors are just easier to come by these days .

 

[CheapSuitG]

I actually obtained a number of PNP germaniums from the PIF, gonna have to give them a try!

 

[PunchySunshine]

The TwinFace taught me all about this.

 

[CheapSuitG]

The TwinFace taught me all about this.

Interesting pedal, added to the list!