Gain control for Linear Power Booster

[Gus]

YouAre

I am not posting the 5k emitter pot circuit is what is best.  I posted that sim because I am guessing you have a 5k pot from your first post and that is one of a few ways to adjust gain in a circuit like that.

First figure out or guess what min gain you want

If you think it is x10 use a 10K collector and a 1K gain pot   OR   a 1K fixed resistor with a rheostat and series cap in parallel, think about the value of the parallel rheostat.  Adjust the resistor divider note the input loading is part of the "sound" of the LPB. 

Less gain a 2K pot  OR  2k/2.2k fixed resistor with a rheostat and series cap in parallel.

and so on

[Gus]

Another thread to look at
http://www.diystompboxes.com/smfforum/index.php?topic=92478.0

compare the graphs.  Look at the low end and note what is going on with the bootstrapped one.

[Gus]

Another circuit a little lower min gain because of the 4.7k collector resistor and 500 ohm gain potentiometer.
I might build this one and adjust C2 for the amp/speaker(s)/cab/volume used
Standard value parts,  OMIT L1, V2, R7, R8 and C3 they are a simple guitar and cable sim.  One single coil pickup(7k and 2.5H), no tone control, volume at max(250k), 10 foot, 22pf a foot cable(220pf).
IMO this is a good circuit to learn to use LT spice and other sims.

[Gus]

Using the same circuit from the last post

Change C2 to a .0068uf cap and you get this.  A treble boost with a gain control and a 4.7k collector resistor

[YouAre]

Interesting!

I've been mucking about with the Muff circuit a bit, there's so much to juggle! I can see why guys can spend a huge chunk of time playing with this circuit...Granted not every change make a big difference, but some changes together will....