The Alberta Clipper: A Muffer Magnified for Maximum Utility

[David]

Well, I guess I'll never be an advertising copywriter.  Probably not a circuit designer either.  Oh, well...   
I can certainly be a circuit "block-connector".  And that is what I've done here.  I think I've come up with a cool set of "circuit blocks".  Let me explain.

Back before Christmas, I was messing around with trying to build a distortion that I could "clean up" with the turn of a dial.  For some reason, those struck me as being a little difficult to find.  Anyway, I was messing with an Electra distortion in the hope that I might somehow twist that into what I was looking for.  I didn't.  But what I did get out of it was Doug Deeper's handy-dandy little trick for changing distortion by connecting a 1K pot between two opposed germanium diodes and ground.  I got a tone control off Howie's Metal Simplex.  The Electra just didn't have the output I wanted.  So I started thinking.

I use a Muffer with the diodes and capacitor bridge removed so it works as a booster.  As I've stated before, it boosts like CRAZY!  I thought perhaps it might be a good candidate for my "implants".  It is.  I can vary the distortion from nothing to screaming.  I can vary the tone from swamp muck lows to icepick-in-the-eye highs.  I haven't put a volume control on it yet, but that shouldn't be a problem.  Boxing it might, but I can work through that too.

The way I did it was to remove the volume pot and hang the diodes off the output capacitor.  The far end of the capacitor then goes to lug 3 of the tone control.  Lug 1 goes to circuit ground.  Lug 2 then goes to the 100K volume pot that used to be at the output of the circuit.

[suprleed]

I can vary the tone from swamp muck lows to icepick-in-the-eye highs.

ROTFL 

I thought this description was hillarious!  I like to tinker with building blocks myself.  Nothing like a successful "inplant" to give you extreme tonal flexibility.  Keep us posted on the progress.

[David]

Yup.  Works great with a volume control too.  Now just have to confirm the distortion control will change the clipping even with all that new hardware hanging off the end of the circuit.  Man, the 2N5089 is one RIPPIN' transistor!

[David]

I almost choked on my own hype.  Once I had the thing fully assembled, it was no longer true that it would go from dirty to screaming.  I decided to see what would happen if I hung the 1K pot off the circuit output instead, and then put the opposed germanium diodes between it and ground.  That was a lot better.  The minimum setting gives me the "crunch" the keyboard player has been looking for.  However, a new wrinkle was introduced.  When I have the distortion cranked, there is a significant drop in output.  Putting an Adjusticator in place of the output pot took care of that problem.

All this got me to thinking that maybe I'm working too hard.  What I have now is a fixed-gain booster feeding a pot and two opposed clipping diodes, which then leads to a tone control, which then leads to an inverting booster which can cut or boost gain.  If I were to redesign the Adjusticator board I'm using, I could put a TL072 instead of a TL071 on there, do the high impedance mod, add an inverting boost with a fixed gain around 10 to replace the Muffer, then add the clipping and tone control stuff.  This would get me to a more compact board and reduce component count.

Hmmm...