Fuzz face using russian gt404g transistors

[karolisd]

Hi, I'm going to build a fuzz face using gt404g transistors. I've etched a board using the tonepad layout http://www.tonepad.com/getFile.asp?id=82 . But gt404g's are germanium NPN transistors. I want it to be negative ground. I want to ask, if I should just build the positive ground version with gt404's and just reverse the polarity of the caps and give the circuit reverse voltage. Also, I want to ask if carbon comp resistors would be better, or should I just stick to regular metal film resistors?

[Govmnt_Lacky]

Your are lucky to have NPN Germaniums. They have the best of both worlds! You get the Germanium "old school" mojo AND you get to build a circuit that can run off of the same power supply that the rest of your pedals use 

1) If using the layout you listed above, just jumer the circuit as NEGATIVE GROUND (top pic) also, PAY ATTENTION TO THE CAPACITOR ORIENTATION. Make sure you follow the negative ground layout when installing the caps.
2) As far as resistors go, that is your decision. Carbon comps for the "mojo" look. Metal film for modern look

Good Luck 

[karolisd]

But I believe I should still reverse the polarity on the circuit since transistors on the negative ground layout are PNP and I'm going to use NPN. And if I use negative ground layout and then reverse the polarity of the circuit, wouldn't it make it psoitive ground? Btw I got those transistors for 35 cents each 

[DavenPaget]

But I believe I should still reverse the polarity on the circuit since transistors on the negative ground layout are PNP and I'm going to use NPN. And if I use negative ground layout and then reverse the polarity of the circuit, wouldn't it make it psoitive ground? Btw I got those transistors for 35 cents each 

Use the positive ground circuit and do the flipping , that's for PNP "negative" ground because it's only a jumper 
Where did you get them ? 

[LucifersTrip]

a couple notes:

you will be simply building the npn version, but using 470 instead of the 330:



and be aware that the pinout is ecb. base is not in center
http://transistor-spravochnik.ru/description/gt404g/38483

remember to breadboard it first to tweak before you commit to solder


good luck

[karolisd]

I bought them from this shop (don't know if they ship worldwide, however they do have an e-shop in their site)
http://www.evita.lt/en/index.php

[DavenPaget]

I bought them from this shop (don't know if they ship worldwide, however they do have an e-shop in their site)
http://www.evita.lt/en/index.php

Wow ! Looks like you're gonna have a good time playing "mojo" .