Fuzz Face with ICL7660S/Max1044 Power Supply Converter

[POTL]

Hi
I want to build a germanium fuzz face with the ability to use a standard power adapter
I need ICL7660S / MAX1044
I use solid ground (without earthen paths)
There is such a conversion scheme

but I do not understand
After the fifth pin of the chip, we get the necessary negative 9 volts
But how do we get a positive land?
Capacitors 14 and 15 go to ground, but what is it? Positive or negative?
How do I properly dilute the circuit if I want to use the ground with solid fill (no tracks)?

[kaycee]

Ground is ground.

think of 9v positive as above ground, and 9v -ve as below ground, ground is still ground, its the potential difference between one rail and the other. Confusing at first, I know.

[amz-fx]

Ground is relative...  it is the point that we have designated as the reference, to which other voltages are compared. For example, the typical wall adapter is marked plus and minus; there is usually no ground on it. So for our purposes, the minus side becomes ground (because we designate it as such) and the plus side of the power supply is then +9v with regard to the ground that we have established.

The charge pump generates a new voltage that is negative when compared to the ground that it is connected to the chip's pin 3, i.e. power supply ground. And pin 5 is negative 9v compared to our established ground.

This revised drawing may makes some of that clearer:



Best regards, Jack

[POTL]

Eureka!
Jack once again many thanks! I thought about this, but my theoretical knowledge is much inferior to practical ones, so I'm sure I'm not sure.
The most important thing is that you sent the picture, because Google interpreter very badly translates terms and I see an unrelated set of words, half of which is translated incorrectly =)
Kaycee also thanks for responding)

[POTL]

Raise the subject
The question has arisen, why use voltage converters, if you can just swap the plus and minus wires?
Or it will not work properly

[duck_arse]

daisy-chained pedals, all using a single wall-source. if your fuzzface has positive ground, and all the other pedals have negative ground, you have shorted your supply negative and positive, and nothing happens except smoke.

an inverter takes +9V and 0V [from external] and gives you 0V and -9V [for internal]. same 0V, everyone is happy and correct.

[POTL]

daisy-chained pedals, all using a single wall-source. if your fuzzface has positive ground, and all the other pedals have negative ground, you have shorted your supply negative and positive, and nothing happens except smoke.

an inverter takes +9V and 0V [from external] and gives you 0V and -9V [for internal]. same 0V, everyone is happy and correct.

Thanks =)

[TejfolvonDanone]

Raise the subject
The question has arisen, why use voltage converters, if you can just swap the plus and minus wires?
Or it will not work properly

If you just swap + and - than as duck said you just short the power supply. But you can operate a fuzz face from regular power supply: http://www.muzique.com/lab/fuzzface.htm

[POTL]

i`m back 
Came across this scheme

In it, conventional pnp transistors that require negative power and positive ground, but instead of a power converter simply turned upside down
It reminded me of the Zvex Fuzz Factory pedal which is a modified tonebender mk ii but also uses an inverted circuit instead of a power conversion
Zvex Fuzz Factory

Tone Bender MK II


These pedals work both from the power supply unit and from the battery, tell us what are the drawbacks of this circuit in comparison with the scheme with a power converter?

[R.G.]

See the direct explanation on this in the separate topic.

[dbwbr]

hi all -
i know this is a frequent topic, so i chose to respond to this thread rather than start a new one.
i built a germanium pnp fuzz face - and started with the standard approach, switching the negative and positive terminals of the battery.
the fuzz sounded great, but i believe this created problems later on with hum/buzz, since the pnp's "ground"  is different than all of the other pedals/amplifiers/guitars that i might use it with.

my next attempt was to switch the power terminals back to normal, as suggested here:
http://www.muzique.com/lab/fuzzface.htm
this absolutely did not work for me. the sound was not overdriven at all, it sounded very mild.  completely different from when the terminals were switched. maybe i'm missing something about this approach?

finally, i ordered some 7660s from amazon. i have built the circuit as included in several different locations on the internet. the schematic above is pretty close to what i used, but there's also this version that has a few different components: https://guitarpcb.webs.com/PDF%20Files/PUFF_v2.1.pdf

i should specify, i used a 4004 diode instead of a 4001 diode. i'm not sure if this would make a big difference.
however, this circuit whines at a high frequency - and it doesn't seem like there's any way to stop it.

has anyone ever tried all of these options and still not been satisfied with the results?

[idy]

Can't be sure what went wrong with the voltage inversion version.

About charge pumps: they whine often. There are 1044 and 7660 with the SCPA suffix: these, when you jumper pins 1 and 8, the frequency goes way up and the whine is not audible. Maybe "S" stands for "super."

In my experience there are low quality chips out there. There are also the 1054 that are better quality but more expensive... they are used when more current is necessary.