Small Fuss/Bass Fuzz - Adding "Mix" Control

[spacefuzz74]

Hello all,

So, I'm a real huge fan of this "Small Fuss" circuit here...it's super minimal, and actually sounds really great.  it's easy to change out the diode and transistor to find the sound you want, especially for people just starting out.

here is the link to the original post:
http://diystrat.blogspot.com/2015/04/building-bazz-fuss-fuzz-pedal.html

I recently built up the "Green Giant", and as i was working on it, I thought how nice the Small Fuss would be with a "Mix" control that would have a clean to full fuzz range.  I found mods for the bazz fuss that have a "tone" control, but not a "mix".

However, my skills are not quite advanced enough to figure out how to add a Mix control into the circuit.

Does anyone have any ideas that can help me mod this layout?  Small Fuss and Green Giant layouts attached.

Thanks!

[Neil mcNasty]

First of all it is important to notice that the "Clean Mix" feature of the Green Giant is not blending between a clean and distorted signal, but is actually a "diode lift" (reduces clipping diodes connection to ground at the output, which then prevents clipping of the output signal), and that this method can therefore not be applied to the Bazz Fuss, since it does not have the same clipping feature.

But that does not mean that it is not possible, but rather that we need to take a different approach to get the desired result.
What is needed is a circuit that runs parallel to the fuzz, that can be mixed at the output.
You could use a blender circuit like this one: http://tagboardeffects.blogspot.no/2012/02/split-n-blend.html (Send=Input of Fuzz, Return=Output of Fuzz)
The only issue that can arise from using the Split'N'Blend circuit, is the fact that the signal is now buffered, and can mess with the sound, if the chosen effect does not like a buffered signal (like in the case with a FuzzFace that demands to "see the guitar pickup" to behave properly/as it should)

If not using the blend circuit above:
Since the Fuzz is quite louder than the bypassed signal, I would consider using a clean boost circuit wired in parallel with the fuzz (input goes to both circuits) in order to get the clean signal up to the same level as the fuzz.

In order to blend the two, you have a couple of options:
#1: Have 2 Volume pots (one for clean and one for Fuzz) and then add a 1K (or higher) resistor at each output (from lug 2 of each of the volume pots) in order to make them sum together without any issues.
You will then have the possibility to set each volume separately.
#2: Remove both Volume pots and run the output of the clean-boost to lug 1 of a (linear) pot (experiment with value) , and the fuzz to lug 3.
Then connect lug 2 to a volume pot as you would usually do.
You now have a Blend/Balance pot between the two signals, and a single Volume control.

I hope this helps you achieve your goal.

Cheers!

[spacefuzz74]

Yes.  Exactly.  Having 2 volume pots that i can "blend" is exactly what I'd like to do.

I'm also going to build the Paralooper and see how that works out.

Thanks a ton for the help!

[nocentelli]

You can't directly apply the "clean mix" from the green giant to.the bazz fuss, since the pot just reduces the amount of clipping from the diodes: The greater the resistance, the less hard clipping occurs: It's not blending in clean. The bazz fuss diode operates in a different way (in the feedback loop, setting the bias aswell) so you can't just stick a pot in there. You can just put a 1k/2k pot in place of the emitter wire to reduce the amount of dirt in the bazz fuss.

[spacefuzz74]

Got it!  Going to try it out.  Thanks!