Transistor question

[Travis479]

Hi, I've been taking electronics for a semester now, and after doing a couple of basic projects in there, I thought I would try my hand at creating my own pedal.  I have a couple of questions though.  For one, it seems like most of the pedals use germanium transistors, I looked at radio shacks website, and I didn't see any there, so I'm wondering, are these extremely hard to come by, or are they pretty common?  Also, if I can't find germanium or silicon, is there any substitute, or I HAVE to use the transistor specified?Secondly, when you say "pot" I'm assuming you just a knob, but when in the schematics, say one end of the pot goes to ground, and then the other half seems to be pointing directly towards the resistor, I would assume that you just put the other half on the positive side of the resistor, right?  I'm a little lost, because in all the diagrams the pots seem to be pointing AT the resistor.  Sorry for the questions, just I'm a bit new, and I have a growing interest in electronics, and these two things seem to be about the only things stopping me from attempting my first stompbox.

[Travis479]

Ok, I think I understand the POT thing, the resistor IS the pot, right?

[petemoore]

  Read GEO Tech of FF for difinitive answer.
 Check out Fuzzcentral and Axis Face for Si Ge sounding FF tech.
 I'm workin' on a AF right now.
 Transistor gains/leakage equation should be looked at.
 I din't like any of the RS Q's in Q swap comparisons.
 Starting with Hfe gains @~70Hfe,  a small handful of 2n2369's and some other NPN variety of gains a little higher, <~150hfe for Q2.
 Rocket uses 2n5088, High Gain Transistors.
 Best thing to do now for a fine tuned FF, is reads on FF's, GGG, lots of FF info around...ROG...etc. I'm back up to a grand total of three usable FF's...
 ...per FF recommends...
  20k trimpot for Q2collector resistor 'replacement' to adjust bais on circuit
 *1k FF gain pot [from Small Bear] for excellent gain control.
 some lower gainers like 2n2369 or 2n4401
 some Med Low Gainers ... easier to find these  
 Try NPN Ge stocks for hybrid or Ge FF in the circuit.
 Ge...you may want to check out the Fuzz Face Calculator at Analog Anchemy...and some of the many Ge FF circuits that are about.
 Trimpot' and 'pot...[the circuit can't 'see' which type is used/either works]
  Trimpot usually means a little thing that can be soldered into a perfboard or PCB that has holes for it. Trimpots are usually linear taper, and could just as well be a surface mount pot on the box with a knob on it. I like the bias adjust on the box of my one FF.
  Pot' is usually meaning a variable voltage divider, with threaded shaft collar for surface mount, I've seen reference to trimpot as pot in context [usually] where the writer left off the 'trim part of the word.

[Connoisseur of Distortion]

actually, the vast majority of transistors you will use are silicon. huge majority. simply look up some recommended part values and take a look at them. 2N3904/06 , 2N5087/88/89, J201, BS170, MPSA13/14, are some of my most common buys.

potentiometers are variable resistors, essentially. I guess i don't understand your question 

[Travis479]

I read more in depth in the FAQ, so I think I understand now.  Thanks for the help.