Hi,
I'm in the process of watching a video regarding selling one's own DIY pedals, and the narrator is stating the "fuzz" pedals need a Charge Pump. He goes on to state that these would otherwise need their own seperate DC power supply. I have a few fuzz builds, and NONE include a C.P. on the circuit. I usually run an ISPOT to connect and power multiple pedals. Does this mean these builds will not be able to be connected with the same power supply that I'm using for say a delay? I'm confused...
Thanks
A charge pump is a way to increase the dc power to say 12 or 18v while just using a regular 9v power supply. I don't have a fuzz pedal that runs at 18v. Nine of the big muffs have one as far as I know. Some do, but you don't have to it.
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If it is a Germanium fuzz pedal using PNP Transistors you need the charge pump to invert the voltage or use its own power supply.
Nearly every fuzz using silicon transistors should be fine daisy chained with other pedals.
Are any of you fuzz pedals using PNP Germanium Transistors?
No. Two use 1n5817s, and the other uses a 1n4148. However, this does bring up a quandary with regard to another pedal build. I have the availability to use a rotator switch connecting four different diodes. Again, this PCB does NOT have a C.P. included. Just to be interesting I've purchased some OA1160 Tungsram Germs, D9B Russian Germ Detector, OA128 Telefunken Blackglass, and 1N60 Hitachi Germs, as well as 1N34As, 1N270s, and Yellow LEDs. Are there combinations I should steer clear of?
Quote from: K3yPr0gg3r on May 26, 2016, 02:41:56 AM
No. Two use 1n5817s, and the other uses a 1n4148. However, this does bring up a quandary with regard to another pedal build. I have the availability to use a rotator switch connecting four different diodes. Again, this PCB does NOT have a C.P. included. Just to be interesting I've purchased some OA1160 Tungsram Germs, D9B Russian Germ Detector, OA128 Telefunken Blackglass, and 1N60 Hitachi Germs, as well as 1N34As, 1N270s, and Yellow LEDs. Are there combinations I should steer clear of?
Those are diodes. Not transistors
If you build a Fuzz Face or other pedal with PNP germanium transistors, the power supply inside the FF is "inverted".
Thus the "ground" is now on the 9V + side.
So you cannot use the same power supply along with other "normal" pedals.
If the FF is the ONLY pedal you are using on that PS then no problem. Plug in and go.
But if you want to use any normal pedal along with the FF, then they cannot use the same PS.
One way around this is to use either a battery only in the FF, or, the FF must have it's own dedicated supply.
OR, use a charge pump inside the FF to invert the power inside the FF so all pedals can share the same power.
OR...
Here's a link to build a no charge pump Fuzz Face or other PNP pedal and still have it play nice with the same power supply (1 SPOT) as all your other pedals.
http://www.muzique.com/lab/fuzzface.htm (http://www.muzique.com/lab/fuzzface.htm)
As Orbis stated those are diodes and a total different story than transistors.
Whatever diodes you use should have nothing to do with the polarity of the fuzz.
You only need be concerned if you are using PNP GERMANIUM TRANSISTORS.
Otherwise don't stress about it.
Quote from: Jules on May 26, 2016, 06:08:08 AMYou only need be concerned if you are using PNP GERMANIUM TRANSISTORS.
This applies to
all PNP transistors, not just germanium.
Actually, it refers only to circuits that use a -9V power supply instead of +9V like we use for most things. You can build a +9V supply pedal with all PNP transistors -- the EHX G.O.D., Keeley Fuzzhead, and many others simply run the transistors upside down. The Jordan Buzztone, Harmonic Percolator, Octavio, and others use a mix of PNP and NPN transistors.
It's rare for a fuzz to run on a charge pump because they're almost always BJT transistors. If you want more distortion it's easy enough to get with them that you don't need more supply voltage.
As others have said, the guy in the video was actually referring to the chip being used as a voltage inverter for when you (a) want to use the original design that ran on a negative supply voltage via battery and (b) don't feel like doing the work to convert it to a positive supply and/or (c) don't want to just use NPN transistors because of reasons.
Thanks to everyone for comments. Looked thru all build docs., and with the exception of Ben's (RullyWow) Model B which has a C.P., all transistors are basic, (MPSA18s, 2N3904/06, 2SC1815, 2N5088, 2N222A, PF5102, BC337, BC170, BC546, BC109, 2N5457, and MPF102).