Ultimate Fuzz Face-Need Help

[reactionkilla]

So I want to make pretty much my idea of the best of all Fuzz Face worlds, and of course that involves both silicon and germanium transistors. I've decided that the best way I feel to do this is to get two separate boards, that is the GGG FF PCBs, and build one of each, as well as having switching arrangements to select between the two.

How I plan to do this is to feed the imput into a DPDT stomp switch, which when in the on position will send the signal to a SPDT toggle switch that will either send it to the Ge board or the Si board. Both outputs on the board will return to the output section on the DPDT switch, which will then send it to the jack. I will wire the DPDT like I were wiring a bypass box, and by doing that should have true bypass. Each board will share the fuzz and volume controls.

The transistors I've chosen are NOS AC128s and a pair of BC109s. The only problem here is that the grounding on the two are different. Is there a way I could wire this to one battery/power input, or would it be easier to just wire a battery to each and have the specific groundings done that way? Is there anything I should do for this that I couldn't think of before? I'm brand new here, but it seems like the best place for a question like this. Thanks!

[jimbob]

This might help

[url][www.beavisaudio.com/Projects/FuzzLab/FuzzCloneMods_V2.gif/url]

[reactionkilla]

I actually tried to do that with my current fuzz face, but ran into the same grounding problems, plus I don't like the switching with the transistors, I would rather have one board for each with correctly biased resistors and different mods tailored to each transistor.

Basically what I need to know is could I power two separate boards with different grounds from one battery or power source, or would it need to be two? Or how would be the best way to do it?

[caress]

your life would be a whole lot easier if you just used either some NPN ge transistors or PNP si transistors.  keep the grounding consistent and you'll have waaay less issues...

[petemoore]

Basically what I need to know is could I power two separate boards with different grounds from one battery or power source, or would it need to be two? Or how would be the best way to do it?
  From what you wrote I can't tell what'd be your best option, heck I can't even tell my own best options without building, testing, trying, re-contemplating sometimes.
  Good way is to pick a PS scheme [ie neg gnd] and stick with it.
  Pos Gnd is ok for the unit, just build the Si version as PNP too, IIRC they purportedly make fine FF's.
  Then you start getting in to 2 batteries...obvious drawbacks there are twice the room, twice the battery maintenance and testing, four 'twisto' wires instead of just two.
  Or MAX1044 voltage converter, which isn't too bad, you can charge some caps very frequently [in reverse polarity] to ~9v, check the data sheet for the Vdrop, consumption, and other details, PNP/NPN in the same box just doesn't fit well with 'ultimate' IME.
  If you connect +/-, it is a direct short in the PS, ignore that they are also connected to 'ground', a no-go.
 

[reactionkilla]

Noted, thanks both of you for your help. The GGG kits come with PNP Si transistors, so I guess I will use those along with the AC128s (which came today, taking roughly 6 days to arrive from Germany, I'm impressed ) and use the BC109s for something else.