Fuzzface npn germanium issues

[pauldumbell]

Ok, so I've never been a pedal guy, the only pedal I ever use is a tuner. Ive build kit tube amps before without too much whoo ha, and I decided after scoring a ton of junk from a garage of a ham radio hobbyist from the 60s, that I would try my hand at pedals. Should be a snap I thought. Tons of germanium transistors in the lot, and I thought the best bet would be to start simple and build a negative ground fuzz face. etching the board, easy. sourcing the parts from my boxes of junk, check. dremel, roger. put it all together and it sounds VICIOUS. BUT...
i used a really high hfe  npn transistor (300) in q2. and q1 is around 115 hfe. Cant get a 9 volt power supply to work at all, and this mother scratcher drinks batteries dry like nobody's business. Plus, it really noisy, but i suppose that is to be expected. I used this schematic and board...

http://fuzzcentral.ssguitar.com/fuzzface/fuzzfacelayout.png

I flipped the polarity on the 22 and the 2.2 uf caps of course. I am assuming the 100 uf and the diode stay put like on the schematic.

am I missing something here?
thanks in advance.
Paul

[senko]

The layout that you linked is for a PNP positive ground circuit.   The instructions on the project page specify some additional instructions for negative ground circuits.

If you want to save money of batteries, look up how to wire up a DC Power Supply circuit.  All that you need is a 12V AC Adapter, a power jack, 9V voltage regulator and some caps to get a steady supply of smooth power for your circuit.  If you need a schematic, I'll post one here that you can use!

Fuzz Faces are very much "sweet spot" circuits that require good component selection and tweaking.  For your personal project, check out http://www.geofex.com/ for some great Fuzz Face notes, especially transistor leakage (a potential reason why your circuit eats batteries). 

[pauldumbell]

thanks senko. if you can lay a schematic on me, that would be brilliant! yea, i do believe that the q2 transistor has a high leakage.

[Thecomedian]

The positive battery terminal is ground in PNP. Negative to ground for NPN.

[pauldumbell]

thanks comedian,
I had that straight from the get go. doesnt work with a wall wart. and i have the poles correctly soldered up.
paul

[Pyr0]

A battery should last a very long time in a Fuzz Face.
To convert that layout for NPN transistors, you will also need to reverse the 100uF cap and the 1N4001 diode. This is probably why it won't work with an external power supply, and would also explain the high current draw.

[LucifersTrip]

Cant get a 9 volt power supply to work at all,

what do you mean by not work?
http://www.guitarpcb.com/photos/Easy%20Pedal%20Wiring%20Diagram.jpg

and this mother scratcher drinks batteries dry like nobody's business. Plus, it really noisy, but i suppose that is to be expected. I used this schematic and board...
http://fuzzcentral.ssguitar.com/fuzzface/fuzzfacelayout.png

that's a layout....do you have an actual schematic?

I flipped the polarity on the 22 and the 2.2 uf caps of course. I am assuming the 100 uf and the diode stay put like on the schematic.

everything with polarity should be flipped if going from pnp to npn

it really noisy

before continuing, check to see if your voltages are in the ballpark of a working one.
http://www.diystompboxes.com/smfforum/index.php?topic=98474.msg860882#msg860882

also, small caps 50-200pf across BC of Q1 and/or Q2 will always quiet things

[Perrow]

The diode is a reverse polarity protection. It works by conducting if you connect the power supply the wrong way. If you haven't flipped it, do so NOW. Not doing so would certainly make it eat batteries.

[Perrow]

It's probably the reason the circuit is noisy too.

[pauldumbell]

WOW!

Thanks to all of you guys for chiming in. Reversed polarity on the diode and 100uf cap, yup. that was the main problem. Also got rid of the 300 hfe transistor on q2 because after flipping the polarity on the diode and the cap, the circuit had a ton of white noise. put 145 hfe in its place and put 100pf caps across the BC of both transistors, and it sounds like it should now. wall wart still doesnt work though...of course wall wart is now showing around 12 volts output even though its rated at 9 volts. strange.

thanks a bunch everybody!

[petemoore]

 
  The supply adapter probably approaches the rated voltage when nearer max current output [high current load].
  With very small current draw [like FF] the voltage, or reducing loads = rising potential of supply voltage.

[LucifersTrip]

.of course wall wart is now showing around 12 volts output even though its rated at 9 volts.

an unregulated one will do that with no load...those are not good for pedals.

are you using an adapter designed for pedals, center negative or positive?

[duck_arse]

as a slight sidetrack, I pulled apart a ded plug pack last week. the overtemp fuse meant o/c primary, as usual. but the rating plate said 12V dc, and there was no filter cap inside. nice one!

[pauldumbell]

an unregulated one will do that with no load...those are not good for pedals.

are you using an adapter designed for pedals, center negative or positive?

ok, you got me there too. it was a center positive, but i flipped it. i think it was from an old answering machine. Im like sanford and son over here...the junk man. i do not think that it is regulated.

[EATyourGuitar]

forget what it says on the wall wart, if it puts out 12vDC then you need a 9v regulator. especially if it is a noisy 12vDC. try a 7809 and read the datasheet. also, bias your Q2 collector to be 1/2 of your supply. that is a good starting point to test if you like that transistor in that circuit. bias is done by selecting a bigger or smaller collector resistor.

P.S. we shun those who say positive ground, try "negative supply". ground is ground. ground does not have a voltage potential to other grounds when they are all connected!

[Thecomedian]

thanks comedian,
I had that straight from the get go. doesnt work with a wall wart. and i have the poles correctly soldered up.
paul

I know that whenever I have a "noisy" breadboarded circuit, the ground and positives are usually not in the proper place.
I don't know why people "shun positive ground". It is positive, with respect to the rest of the circuit.