I'm using the Bazz Fuss as a sort of jumping-off point to build my own distortion/fuzz/whatever. I've been reading the Cook Your Own Distortion article for a while now, and want to experiment with some of the things mentioned there. Since that article deals primarily with Op Amps and the Bazz Fuss uses transistors, how do I go about the following:

Adding a basic tone control. According to the CYOD distortion, the tone control goes somewhere between the In and Out jacks...which leaves the whole circuit up for grabs. I see that the Bazz Fuss has a resistor to capacitor at the front end of the circuit which I see is a low pass filter. By replacing the resistor with a pot do I magically make it a tone control?

Also, I'd prefer to not have the volume cut out when the pot is all the way to the left. Does moving the pot to the front of the circuit like in the Drive Control example work to eleminate that? If so, where do I connect the pot lugs? Do I just move the wiper contact to the input cap?

I think that's all the questions I have. I'm sure I forgot something because I'm off to bed...sorry if some of this is nonsensical.

Cook Your Own Distortion
url]http://privatewww.essex.ac.uk/~mpthak/Distortion/[/url]

Search for "Big muff tone stack" and "stupidly wonderful tone control" for some versions
which will work a treat.
Yes the tone control can go "anywhere" but to be honest, "after" distortion/fuzz happens
is by far the best place IMO, after all the front end is where your guitar enters, if you
want it "duller" here, just turn the gtr tone pot down  !
After the "boosting/Crunching" gives you more to play with and helps you dial out some
harshness from the distorted signal .... yes ?
"SWTC" is right before the output pot and is NOT a serious volume sucking circuit 

Marty.

Thanks for the tone circuit suggestions! I'm looking into them now.

I'm trying to calculate my limit frequency according to the CYOD article, but since it's been a while since math class, I wanna make sure I'm calculating right. I hope some brainiacs out there can help! 

f=1 / 2 * P I* R1 * C1

I know my limit frequency is 130.81Hz (I play in open G)

So to figure for C1 we use

C1 = 1/(2 * 3.14 * R1 * 130.81Hz)

That's easy enought to do...but how do you go about finding the optimum value for R1? Because the article deals with Op Amps (which I'm not using) the gain is set by R1/R2. If I'm using transistors this doesn't apply (correct?) The article does mention using at least 100k resistors because of impedance, so should I just stick with that as a base number? If I do use 100k for R1:

C1 = 1/(2 * 3.14 * 100,000 * 130.81Hz) = 0.00000001217 = 12nf

Is this correct?

I divided 0.00000001217 by 0.000000001 to get the nf value.

The scientific notation still throws me off a little.

Any and all help is appreciated. I really wanna get off on the right foot and design my first circuit correctly without just throwing stuff on the breadboard for no apparent reason (although there is a time and a place for that!)

Hmm, well the "maths" part is what i resort to when all else fails
I tend to use advice from here/ known circuits etc  and MY EARS  !!
Op amp calculations are a little different, you'll see many "Fuzz" circuits
made with transistors, with everything from 0.002uf input caps to
4u7 input caps !!
In general, to reproduce guitar frequencies and not "thin out" your
sound, then in/out caps of 0.047  to 0.22 are going to be fine
Coupling caps of 0.1uf and above are "the norm" and to reduce some
high end "fizz" 470pf through to 0.0047  ( 4n7 ) will work when tied
from signal to ground .
Not very "techie" as an answer, but i hope that helps you.
Have you tried searching for the "duncan tone stack calculator" ??
Also the FAQ and "simple mods/tips" wil help you a lot  .
Use sockets and buy yourself a selection of "poly caps" from
1n ( 0.001uf ) up to 470n ( 0.47uf ) and you'll have many options
covered  !

Marty.

The "not very techie" answer has helped. Sure I want data, but that doesn't mean I won't settle for learned values! I have the circuit on a breadboard so swapping out parts isn't a problem. I do still have some questions regarding the tone control though. You suggested placing the tone control after the distortion happens which makes sense. Where does the distortion happen exactly? I'm assuming after the transistor because it's acting as an amplifier, right? So would I connect the "IN" of the tone control to the emitter of the transistor, or do I connect it after the transistor/diode junction?

And do I connect the "OUT" on the tone ciruit to the same lug of the mono jack that I already have the volume pot connected to? I think the out is confusing me more than the in.

Just so we're on the same page:

I am sure someone will correct me if I am wrong, but I believe the "in" from the tone circuit should hook up right after c1 on the bass fuzz, the side of c1 that goes to the volume control of the bass fuzz.

Then, the "out" from the tone circuit would go to "where c1 is attached to the volume pot the way it is in the bass fuzz circuit."

Peace!
Arn C.

In to tone control from where C1 is ( but omit it ! so direct from junction of R1/Q1 )
Out from tone control to where C1 was ( include it here before volume/out pot as schem)

You could have a "C1" on both sides to be fair, but it's not required.
Your "out" connection will attach to lug 3 of the vol pot, via the C1 ( 0.1uf ? )
Volume pots are alway's the same, Lug 3 from circuit, Lug 2 to output jack
and lug 1 to ground.

Cheers,
Marty.

Thanks Marty, you've been a great help. I've edited the schematic according to your description of what to do. Does this look right?



I'm on my way out so I don't have time to breadboard it. Sorry there's no values on the schematic, here's the original:

http://www.home-wrecker.com/bazz1.png

Yup looks good to me !

Marty.

Works perfect! Thanks again! Now it's time to start swapping components and see what happens!

Please forgive the self-promotion, but I've recently done the same thing you are doing here, i.e. marry a bazz fuss to a BMP tone control and tweak values etc. It will be interesting to compare our results.

Here is my build report:
http://www.diystompboxes.com/smfforum/index.php?topic=38682.0

-- T. G. --

Not the same approach, but in the spirit of Mark's Stupidly Wonderful Tone Control, here's what I've been playing with:

Sorry, no clips, but it's..., well, interesting!