Favorite Bazz Fuss Mods, Anyone?

[superferrite]

Got this thing working great and it is wicked cool swapping things around.  I found a ton of threads in the search function, but I was wondering which mods work best with this simple circuit after you guys have lived with it a while.  I need at least ONE other knob to twiddle! 
Anyone want to volunteer some links for a brother?

[geertjacobs]

I just built one too and tried it (on bass) during band practice.
A comment read a lot about fuzzes on bass is that the lower bass notes are cut a bit too much when using a fuzz.
That was confirmed when playing with the band.
I'm probably going to use the bazz fuss in combination with a blender that adds a parallel clean path that is mixed with the fuzz.
So my extra knob would be a blend, but unfortunately it's going to take a lot more circuitry than just one knob. 

[jayp5150]

I have one built into my bass (primarily a guitar player, though).

I used 10uf on the input and output to let more lows pass through. I also used a darlington (homemade one--2 2N5089's), and I used a diode "loop" (two in parallel--opposite directions) instead of the single diode. I think I used 1N914's.

I don't think I have any sound clips, but if I dig some up, I'll post them.

Edit: I didn't catch the other knob thing... my bad. You could always put an input cap blend on there. Just use a smallish cap on the input, then parallel that with a larger cap and a pot wired as a variable resistor. It's a poor man's tone knob, and works well on fuzzes.

[ambulancevoice]

you can add a gain pot which can be useful, although the bazz fuss really does sound best at full gain
a bias pot is probably recommended, the 10k resistor doesnt hit the fuzz's sweet spot, so if you adjust the bias yourself you can dial in the best sound
id say a 100k lin in place of the 10k resistor, wired like 9v+ -  pin 1 - pin2 connected to pin 3 - pin 3 to collector
there is also that thickness control on the Deluxe Bazz Fuss
according to the home wrecker/run off groove notes on it, if you use it with a 1n4148/914 you can dial in the sound that you would get when using other diodes, like, for example, say at max thickness it would sound sorta like the LED, in the middle, like the germ and silicon combo or something
when i get a breadboard im gonna experiment with a way to prevent the low end from getting clipped, maybe by putting a small cap before the diode to only let the high end get clipped

[mac]

http://www.diystompboxes.com/smfforum/index.php?topic=62944.0

My favorite mod is to use Ge transistors.
http://www.diystompboxes.com/smfforum/index.php?topic=60531.0

I was about to post it:


mac

[raven72]

While I like the original Bazz Fuss with it's Synth-like Fuzz - I wanted to modify it for a more traditional distortion for playing thrash metal (think early Metallica).

I used:-

Transistor BC548 (any NPN bipolar with a hFE of about 120 should work)
Resistor 100k (with the BC548 anything between 10k and 100k works fine
Input Capacitor 0.02 uF Ceramic
Output Capacitor 0.002 uF Polyester
Clipping Diode Green LED

I also used only 6 volt supply instead of 9 as I want to run it on 4xAA batteries instead of a single 9v cell.

One thing I did learn working this out is the lower the capacitor values the more bass is cut from the sound (which was required here to get the 'thrash' tone that I wanted.

The trade-off being,  the more bass you cut also lowers the amount of note sustain (although not enough to be a major problem)

Also different types of capacitors give different sound. eg:- 0.2uF polyester can sound different to 0.2uF Electrolytic, even though they have the same value.

So the moral is,  when developing a Bazz Fuss for a certain sound have plenty of capacitors of varing values AND varing types.

[brianq]

I like to combine different diodes:
1n4007 & 1n914
1n914 & LED
Or instead of traditional diode across base & collector try symmetrical clipping diode arrangement.

[raven72]

I like to combine different diodes:
1n4007 & 1n914
1n914 & LED
Or instead of traditional diode across base & collector try symmetrical clipping diode arrangement.

diodes combined in series or parallel???

[brianq]

Series and parallel

[bassmannate]

Built the "deluxe" version and love it. Gives you a bit of variation without having to swap out parts. Being able to change the gain and input capacitance with a knob makes it so much more useful. You can get some really cool overdrive sounds or go full on synth-like fuzz.

[Ben Lyman]

Ya, it's a good one. Did you see my version of it, the Black Lightning MKII ?
I put a cap on the wiper to eliminate crackle on the dirt pot and a switch for Si diode for that insane synth tone or LED clipping for a crunchier more tube-like OD
Pics and vid in the Pictures section above

[mac]

Favorite Bazz Fuss Mods, Anyone?

First let me explain the Bazz Fuss bias.
Doing some reverse engineering, I noted that in orther to get the best of it, the voltage drop across the diode must be almost zero. That is, the voltage drop between the collector and the base must be zero.
But IIRC diodes turn on fast with very tiny currents. And at the same time the diode must feed the base. There's the rub

If you use a high gain device, darlington or mosfet, you need very little current across the diode to feed the base, and at the same time to have almost zero voltage drop across the diode.
That's why a 2n3904 needs a much higher collector resistor (+100k) than a darlington (10k).

IMHO darlingtons, sound better.

Having said that, here is my favourite mod:

The diode is forced to clip and bias the circuit at the same time. What if I help it a bit by adding a base resistor?



With this trick a single or darlington germanium can be used, although the bias pot must be adjusted oftenly as temperature makes the bias point drift 

mac

[raven72]

been tinkering with my 'heavy metal' version and came up with this combination

Transistor BC548 (as always)
R1 10k
C1 0.033 uF
C2 2n2

This time I used a 1n4148 signal diode for clipping and a 50k linear potentiometer on the output side to control the level

I must say, I really like the 'sizzle' in the crunch for power chords and palm muted notes

As this is the first combination if have truly come up with on my own I'm going to call it the "Metal Fuzz MK-1"

If anybody tries it, please comment as feedback would be appreciated.

[Groovenut]

Here's one I did a while back, still use it

[raven72]

Here's one I did a while back, still use it

While I love the look of the schematic - It knida takes away from the 'simplicity' of the Bazz Fuss...but this thread is about Mods...lol

[duck_arse]

Transistor BC548 (as always)

do you ever test for gain?

[raven72]

Transistor BC548 (as always)

do you ever test for gain?

No, just go off the data sheet that says the BC548 has a hFE of 120 - then just play it by ear on the proto-board

[raven72]

Here is a question that I hope someone can help me with:-

I simulated the volume control turned halfway up with a pair of same value resistors as a voltage divider on a Bazz Fuss.....when I replaced the resistors with an actual potentiometer turned to it's middle position the sound has more bass in it (which I don't want). Does the potentiometer have a capacitance value that is affecting the sound that a pair of resistors don't?

[thehallofshields]

A darlington Bazz Fuss has the sustain of a muff, but sounds like it's all even-order instead of odd-order harmonics. Is there any way to rebias it to change that balance?

[mac]

Does the potentiometer have a capacitance value that is affecting the sound that a pair of resistors don't?

The capacitance of a pot, if any, is much, much less than the bypass resistor.
Is your potentiometer linear or log?

A darlington Bazz Fuss has the sustain of a muff, but sounds like it's all even-order instead of odd-order harmonics. Is there any way to rebias it to change that balance?

You can try a big bypassed emitter resistor to send the collector above 7-8 volts... just guessing.
A pot wired as a variable emitter resistor with a 47uf cap can do it.

mac