Recommend a good Ge/Si dual Fuzz for a beginner?

[powerplayj]

As I have become older (32), my cd collection has gone from contemporary rock back to the 70's/late 60's and I am smitten with fuzz.  I like the Ge fuzz tones of Trower and early Hendrix yet I would hate to miss out on the Page/Eric Johnson Si fuzz tones.  I have modded several of my current pedals (TS-808 mod, Jack Orman's Rat mods, Crybaby TB mods) but, have yet taken on a pedal from scratch.

I would like a fuzz to be my first DIY project but, I want it to be versatile enough to stay on my board, hence the idea of a Ge/Si switch would be favorable.  Although I am not absolutely sure what "biasing" means, I gather it has to do with changing the resistance via a trim pot in order to change the voltage somewhere around the transistors (emitter, collector, base???).  I also know that the bias may differ for Si and Ge fuzzes.

With that said, does such a project exist on a beginner level?  If so, is it possible to also include a fixed resistor with the Ge/Si switch such that the bias changes as the transistor is switched, thus, minimizing the use of a trim pot?

[B Tremblay]

Check out Joe Gagan's Easy Face.  Not switchable modes, but combines the best characteristics of both transistor types.

[petemoore]

Multi- Face, I'm surprized B. didn't mention.
 Here's my face 'rant'.
 socket Q's and caps.
 Trimpot Q2 collector or use Multi Face.
 If you work at making different Faces, you can get some gruesome and beautesque results!!!  

[bwanasonic]

I love Ge fuzz, but it does present problems for regular gigging due to temperature instability. If you search the archives, there is a lot of info on *piggybacking* Si transistors, and a design that became known as "Ms. Piggy". Anyhow, there a lot of variations on the basic design. The Multi-Face that Pete mentioned is kind of a little Fuzz Face "Lab" for checking out the variables. One of the first things you will find out about the Fuzz Face is that it doesn't always get along with other pedals, especially anything with a buffer (read: Boss, Ibanez, many commercial pedals in general). It may take some work to integrate the FF into your pedal board. One final thing to consider is that the players you mention all use Fuzz as one component in a signal chain that centers on cranked tube amp tone. A Fuzz into a clean and/or solid state amp is not always the most inspiring tone if you are going for Jimi and Eric Johnson. OTH- If you are going for cheesy Indian/Bollywood movie soundtrack...:wink:

Kerry M

[powerplayj]

Multi- Face, I'm surprized B. didn't mention.
 Here's my face 'rant'.
 socket Q's and caps.
 Trimpot Q2 collector or use Multi Face.
 If you work at making different Faces, you can get some gruesome and beautesque results!!!  

Looks like a cool build with a lot of customizable potential.  How easy would it be to use two sets of transistors (Ge/Si ) and switch between them?

[petemoore]

I'd say as easy as including sockets for Q's.
 also, building a FF board isn't that super troubleysome, a couple varieties I use for testbed boards, 1 PNP pos Ground 1's NpN Neg Ground.
 Both are moddable, 1 I started with a long legged 100k [for the Q1 C res. ...the 33k] cause you can always go lower, then hooked a 100k pot to that [makes 50k right there, use 500k and measure] across it so I could tune that. But it's easier to just use a 100k trimpot on the board there. This R makes 'some' little dif between 33k and 100k. Reads told me/I trusted, and I didn't try over 100k there. I just use 33k - 47k there...
 Same goes for every resistor on the board. use 2k2 for gain or 2k's plenty, then turn the gain down, or set the max R by paralleling a resistor across lugs 1 and 3. Sticking near stock values seems to work well for most of them, the FF's Q2C/R needs trimpot anyway IMO, they're way EZ for tuning FF's these days and cheep...or build MultiFace.
 Changing from pos to neg ground is:
 Polarized caps and P.S. pole reversal
 [this means the bypass cap 22uf and any others if you choose them for input or output, I use films for those]
  I use socket for that bypass cap, the 22uf, and you can try 4u7 - 47uf there, I like the 22uf for the most part.
 So electros and battery clip + and _ [pos and neg] must all be reversed...to change it from 'PNP friendly' to npn version so you can use your different polarity transistors.
 You could put a plug on the battery clip and a jack on the board PS connections...socket the polarized cap, and plug your way instantly from pos to neg gnd. board setup.

[bwanasonic]

The classic Ge Fuzz Face was PNP/ Positive ground. Most Si versions are NPN/Neg. ground. If you want to explore switching between tranny types, I'd go with NPN/ Neg. ground. You won't be able to use the "Holy Grail" germaniums (AC128, NC275), but switching between grounding schemes is problematic at best. You may want to experiment with something like the Multi-Face ( or a breadboard) and come up with what is a "Best Of Both Worlds" design for your setup, rather than trying to switch out trannies on the fly. It may be more useful/functional to switch something like a cap or a diode/diode pair for an expanded tonal pallet. I'd also recommend trying a Rangemaster build. It's simple, a staple of many classic rock tones, and pairs well with a Fuzz Face.

Kerry M

[petemoore]

Yupp, for the most part tranny switching includes possible rebias, re-tuning of caps etc.
 yem\ I have a couple FF's here, couple testboards too. I figure why build just one...

[powerplayj]

Thanks guys.........