Mods here: Bazz fuss, electra distortion ect.

Started by Havaden, January 06, 2014, 12:39:12 PM

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Havaden

I could not find a topic for modding these simple circuits.
I had a long time figuring out how to get the bazz fuss to sound a bit like a fuzz face instead of a misbiased 8-bit fart. :P
But yeah, post all the mods you like, cap values, transistors, diode arrangments, pots  ;D


Input cap: 333 = 33nF
Output cap: 105 = 1uF
Transistor: BC546B
Diode: 1N4007
Resistor: 680K
And a fuzzface fuzz control below the transistor with 10K pot and a 20uF cap

Original circuit:


Fuzz face fuzz control:
It's not always easy, but it's never impossible :D

Gibson SG Special worn brown 2006 (W. Bigsby b3)
Squier bullet fiesta red 2009 with a ton of care and mods.
Chibson LP Custom 2015 (Fixed broken neck)
Gibson LP Junior 2009

Domin321


Bunkey

#2
I spent a long time on the Bazz Fuss circuit.

https://www.diystompboxes.com/smfforum/index.php?topic=123686.msg1170560#msg1170560

Really didn't know what I was doing (and it shows) but you might find some of it interesting.

At the end of the day, a bazz fuss sounds like a bazz fuss; it will never sound like a fuzz face because it's not one.

The gated 8-bit fart is inherent of the way it switches the transistor using that diode configuration. There are some cool sounds you can make with it though, see page 2 and I'll post a piece below that I recorded with a later iteration, but if you're looking for a bit more of a refined tone then I'd recommend a different configuration that biases the transistor into conducting all the time using resistors and deals with the ac signal clipping seperately.

This is about as good as I got mine - was never into super high gain transistor sounds anyway and just like the pretty psychadelic noises it makes with germanium diodes:




Edit: Haaa I just realised this thread was op in 2014  :icon_lol:
...just riffing.

iainpunk

i'd like to add a ''''mod'''' of the 'buzz box' double bazz fuss
i was thinking about Harmonic Percolators and thought; "i can do that worse"
i added the biassing scheme from the Bazz Fuss, i used a reverse Beta 2N2222A for the NPN transistor, the reverse Beta has a certain, more rotten character to it, but it also biasses badly, and i added a resistor parallel to that gain stage to keep the first gainstage happy in terms of current.

i called it the Harmonic Instant Coffee

percolator coffee is nice, high quality, fine tuned by the masters of coffee making and soft in aroma's.
instant coffee is mediocre at best, poor quality, the cheapest beans are used and can be really harsh tasting.
Harmonic Percolator is nice, high quality, fine tuned by the masters of pedal building and is soft in tone.
Harmonic Instant coffee is NOT NICE, simplistic, cheapest parts are great for it, and can be really harsh sounding.

the resistor values i use keep changing on my breadboard, i currently have a 100k for the resistor from Q2 to 9v. and a 39k from the 9v to the 100uF ''middle cap''.
Q1: BC519
Q2: 2N2222A *
D1: BYX10 **
D2: Amber/Yellow LED

i hope it tickles you guys'es fancy.
cheers, Iain

* (C and E reversed in mine, if you decide to us it with the C and E normally, you don't need the resistor to the middle cap)
** (1N4007 is way cheaper, and sounds really close)
friendly reminder: all holes are positive and have negative weight, despite not being there.

cheers

OiMcCoy

What perfect timing! I just finished up a PCB design for the Bazz Fuss.



Rob Strand

#5
QuoteI had a long time figuring out how to get the bazz fuss to sound a bit like a fuzz face instead of a misbiased 8-bit fart.
IIRC Red LEDs help.

You can also clean it up a bit with 470R to 1k in the emitter.

Try both separately.

It's a long time since I've actually built one.
Send:     . .- .-. - .... / - --- / --. --- .-. -
According to the water analogy of electricity, transistor leakage is caused by holes.

Bunkey

Quote from: OiMcCoy on February 21, 2021, 06:37:56 PM
What perfect timing! I just finished up a PCB design for the Bazz Fuss.


This forum is telepathic don't you know.

Put some thought into an idea, get real excited about it, and I guarantee it'll show up on the feed. 

:icon_lol:
...just riffing.

Ben N

#7
If you want more sustain and less fart from a Bazz Fuss, add a simple 1-transistor boost at the input (Gus's NPN boost, or a BMP input stage) -- at which point you basically have an EQ-less Whisker Biscuit (although I would include the BMP sustain control or possibly a switch to go between singy and farty).
  • SUPPORTER

iainpunk

Quote from: Ben N on February 22, 2021, 04:26:33 AM
If you want more sustain and less fart from a Bazz Fuss, at a simple 1-transistor boost at the input (Gus's NPN boost, or a BMP input stage) -- at which point you basically have an EQ-less Whisker Biscuit (although I would include the BMP sustain control or possibly a switch to go between singy and farty).
both: add a emitter resistor and up the resistor to over way over 100k. this makes the output impedance worse, but that can be solved with a direct-coupled buffer:


cheers, Iain
friendly reminder: all holes are positive and have negative weight, despite not being there.

cheers

duck_arse

Quote from: OiMcCoy on February 21, 2021, 06:37:56 PM
What perfect timing! I just finished up a PCB design for the Bazz Fuss.



is your diode backwards? you should mark/name one of the transistor pads, E or C, so any transistor can be oriented correctly.
don't make me draw another line.

OiMcCoy

Quote from: duck_arse on February 22, 2021, 09:24:36 AM
Quote from: OiMcCoy on February 21, 2021, 06:37:56 PM
What perfect timing! I just finished up a PCB design for the Bazz Fuss.



is your diode backwards? you should mark/name one of the transistor pads, E or C, so any transistor can be oriented correctly.
It is. On the schematic its correct, but its inverted when I take it over to PCBNew. It's very annoying but I cant seem to figure out why its happening.

iainpunk

Quote from: duck_arse on February 22, 2021, 09:24:36 AM
Quote from: OiMcCoy on February 21, 2021, 06:37:56 PM
What perfect timing! I just finished up a PCB design for the Bazz Fuss.

is your diode backwards? you should mark/name one of the transistor pads, E or C, so any transistor can be oriented correctly.
or its left up to the builder how to orient the transistor, quite a lot of them work just fine in reverse Beta in circuits like the bazz fuss
the diode needs to be oriented the right way around tho

cheers
friendly reminder: all holes are positive and have negative weight, despite not being there.

cheers

OiMcCoy

Quote from: iainpunk on February 22, 2021, 07:58:50 AM
Quote from: Ben N on February 22, 2021, 04:26:33 AM
If you want more sustain and less fart from a Bazz Fuss, at a simple 1-transistor boost at the input (Gus's NPN boost, or a BMP input stage) -- at which point you basically have an EQ-less Whisker Biscuit (although I would include the BMP sustain control or possibly a switch to go between singy and farty).
both: add a emitter resistor and up the resistor to over way over 100k. this makes the output impedance worse, but that can be solved with a direct-coupled buffer:


cheers, Iain
I just bread boarded this out and it sound pretty cool. Definitely more stable sounding, even allowing you to roll down the volume on the guitar without getting gated. It is very bright tho. Going to try increasing the caps to get more low end in, but it might be worth having a treble bleed. And finally... its very quite. Well below unity. Not sure if all these "issues" are on my end or not, but I figured I would share my results. It's definitely on the right path to something awesome.

Fancy Lime

Quote from: OiMcCoy on February 22, 2021, 10:08:15 AM
Quote from: duck_arse on February 22, 2021, 09:24:36 AM
Quote from: OiMcCoy on February 21, 2021, 06:37:56 PM
What perfect timing! I just finished up a PCB design for the Bazz Fuss.



is your diode backwards? you should mark/name one of the transistor pads, E or C, so any transistor can be oriented correctly.
It is. On the schematic its correct, but its inverted when I take it over to PCBNew. It's very annoying but I cant seem to figure out why its happening.
That's curious. I just checked, my KiCad places the diode footprints correctly. I suspect it may be a bug in the footprint itself. Which of the many diode footprints did you use? I'd like to check if I can reproduce the problem. I tested D_T-1_5.08mm_Horizontal. that works for me.

Andy
My dry, sweaty foot had become the source of one of the most disturbing cases of chemical-based crime within my home country.

A cider a day keeps the lobster away, bucko!

OiMcCoy

Quote from: Fancy Lime on February 22, 2021, 01:43:12 PM
Quote from: OiMcCoy on February 22, 2021, 10:08:15 AM
Quote from: duck_arse on February 22, 2021, 09:24:36 AM
Quote from: OiMcCoy on February 21, 2021, 06:37:56 PM
What perfect timing! I just finished up a PCB design for the Bazz Fuss.



is your diode backwards? you should mark/name one of the transistor pads, E or C, so any transistor can be oriented correctly.
It is. On the schematic its correct, but its inverted when I take it over to PCBNew. It's very annoying but I cant seem to figure out why its happening.
That's curious. I just checked, my KiCad places the diode footprints correctly. I suspect it may be a bug in the footprint itself. Which of the many diode footprints did you use? I'd like to check if I can reproduce the problem. I tested D_T-1_5.08mm_Horizontal. that works for me.

Andy
Diode_THT:D_A-405_P7.62mm_Horizontal

OiMcCoy

#15
I think the issue may be the symbol used in the schematic. 

- edit - this was the issue. Glad I finally found the answer to this very annoying problem!

iainpunk

Quote from: OiMcCoy on February 22, 2021, 12:47:06 PM
Quote from: iainpunk on February 22, 2021, 07:58:50 AM
Quote from: Ben N on February 22, 2021, 04:26:33 AM
If you want more sustain and less fart from a Bazz Fuss, at a simple 1-transistor boost at the input (Gus's NPN boost, or a BMP input stage) -- at which point you basically have an EQ-less Whisker Biscuit (although I would include the BMP sustain control or possibly a switch to go between singy and farty).
both: add a emitter resistor and up the resistor to over way over 100k. this makes the output impedance worse, but that can be solved with a direct-coupled buffer:


cheers, Iain
I just bread boarded this out and it sound pretty cool. Definitely more stable sounding, even allowing you to roll down the volume on the guitar without getting gated. It is very bright tho. Going to try increasing the caps to get more low end in, but it might be worth having a treble bleed. And finally... its very quite. Well below unity. Not sure if all these "issues" are on my end or not, but I figured I would share my results. It's definitely on the right path to something awesome.

most bazz fuss types are quite low volume, that's why people like using LED's in them, especially if its a last gain stage of a design. the stock 4148 gives about the same volume as a single coil an LED gives double that, on par with most humbuckers. i personally don't mind the lower volume, since i have my guitar at 30 to 40 % (which works great since i have a "bright cap".) so i have most effect volumes rather low anyways.
if you want a softer tone, add a capacitor parallel to the diode, around 100p should be a good starting point, and you can go up or down to taste.

cheers, Iain
friendly reminder: all holes are positive and have negative weight, despite not being there.

cheers

OiMcCoy

Got my diode issue sorted. Here is the refined version... in mind blowing 3D!


iainpunk

Quote from: OiMcCoy on February 22, 2021, 02:47:10 PM
Got my diode issue sorted. Here is the refined version... in mind blowing 3D!

that looks super neat!

looking forward to see your next design

cheers, Iain
friendly reminder: all holes are positive and have negative weight, despite not being there.

cheers

Marcos - Munky

Quote from: OiMcCoy on February 21, 2021, 06:37:56 PM
What perfect timing! I just finished up a PCB design for the Bazz Fuss.


Nice layout. Very small and symmetric. But that "red" trace between the transistor pins is too close to the base pin (center one). Easily solved if you change it to "green" and run it over (or under) the red trace that connects R1 and C2.