Looking at ROG's Whisker Biscuit,



I found out that it has no gain control. I want to add one.

Will it be just a 100K pot after the first stage like that of a Big Muff pi?



Am I on the right track? Any other things to put there?

Thanks for any help

Hey man!

Why not try a bypass capacitor with a pot for controls across the collector resistor of the first gain stage. Thats what i would do. Although the guys here might have better ideas  

Sorry pre, I'm still kinda newbie on these stuff. :roll:  Can you elaborate more, maybe a rough diagram?

BTW, is the 1K resistor to ground on the sustain pot of the BMP prevents the effect from muting if the setting is at 0?

You could set up a volume pot between the first & second stage instead of that 10k resistor, use a pot around 20k or so, as long as you're in that region it shouldn't really matter. That way you can set up how much juice is driving the second stage.

That 1k resistor is preventing the second stage from being shorted to ground. Maybe that's to stop it oscillating or something, but I'm not sure about that.

As noted on the schematic, we suggest using the guitar volume control to adjust the gain.

You can implement the BMP Sustain control between the first and second stages, but it may not sound too impressive at lower settings since a Bazz Fuss needs a fair amount of signal to prevent gating.

Another option is to replace the 10k series resistor between those stages with a 4k7 resistor and a 50k (or so) pot wired as a variable resistor.  This may allow for some control of the gain without losing signal to ground.  I haven't tried this, so I may be way off.

What im talking about is putting a capacitor in series with a variable resistor. across R4 on the BMP circuit diagram. Get it?  :wink:

(Kumbaga nakaparalel tong cap sa R4)

If my knowlegde serves me right putting a bypass capacitor on a class A circuit increases its gain. In my experiments it also causes the circuit to be more open to RF interference. maybe it just needs shielding. bread board it to be sure

On a breadboard you can be 80% certain it'll pick up RF

80% chance huh? Maybe next time ill try boxing up my projects to get rid of RF

Ive given up on a lot off circuits for that reason heheheh  :roll: