Bazz Fuss optimizations: the fish variety

After the successful building of my first Bazz Fuss, I was ready to try more. There are some pointers on the Bazz Fuss page at home-wrecker, so I decided to check them out:

1. put the transistor and diode in a socket, so you can actually try some different ones without having to build a new board every time :)
2. add a pot between the emittor and ground, so you can dial back the fuzz a bit
3. use a 10k collector resistor instead of a 100k resistor, for... reasons.. :)
4. make switchable (on the website it's done with a balance pot) input caps to get rid of the ultra low end. (Hint: this did nothing for me..)

So, this is how it came out:

BF-2 Fish Fuzz, artwork by Petra Randewijk

When I finished putting it in the box, I found out that I wired the volume pot the wrong way around, so this is my first pedal with an Attenuation knob. The unmarked mini toggle adds a .47uF Wima MKS cap to the input, which should give a total of around .33uF input.

The board: L-R: the .1uF output cap, 10k collector resistor, unmarked LED, BC107, 4.7uF input cap

I tried a lot of different diodes and transistors, some of which were more successful than others. On the transistor side:

• MPSA14: overpowering amount of gain, heavy compression
• BC517: another Darlington, a little bit more controlled than the MPSA, but not my cup of tea
• BC109C/BC108C: a lot of gain, but pretty okay
• BC550C: the one I used in the BF-1: nice but a bit compressed
• 2n2222A: I don't like the high end on these, and the note trails are very fizzy, severe gating
• AC127: ouch, my vintage AC127s are unhappy, loads of hiss, very little signal, farty distortion.
• BC107: just the right one for me, I love the open low-mid range on these and even though the high end is not as controlled as for example on the BC550C, it's very musical, I think.

on the diode side:

• 1n4148: classic Bazz Fuss fuzz. Lots of compression, a lot of high end fuzziness
• Germanium diodes (probably 1n34a): A lot less compression, but the mid range gets a bit honky and some of the low end sounds like it's killing the diode
• OAZ205: A vintage (early 1960s) Germanium Zener Diode. Very nice open distortion, but very little high end
• Red LED (5mm): dark distortion, but the low end is too much for this one, some of the notes sound like they don't get clipped at all.
• unmarked clear LED: the right one! just a hint of compression, the open LED distortion characteristic, but with a better high end. All in all a very nice mix between the classic diode fuzz and the dark LED distortions. It's sad that I only have two, and I'm not even sure what color it is..

I've already taken this plastic box on the road with The Legendary Pink Dots and it performed very well. I think I like the magic toggle in the "up" position a bit better, but I'm not even sure if that's with the extra capacitor engaged or not..

BF-2 Fish Fuzz schematic

Back to building: the Bazz Fuss

In the years after building that first successful Fuzz Face I just built a couple of passive boxes, among which a looper/switcher that I use a lot.

Also, after watching how older Meyer Sound processors use LEDs to clip/compress excessive input levels, I decided to modify my DOD OD-250 Overdrive/Pre-Amp to have LEDs instead of the normal silicon diodes that are used to clip the signal. The result was a lot more output and a more "open" distortion characteristic. Eventually the footswitch started failing so I got an MXR Distortion+ and did the same mod on that one. 

Earlier this year I was looking around the internet in search of a nice little project I could do and found the Bazz Fuss on home-wrecker, from a design by Christian H, (neither of these pages have been updated in a while, by the way) and thought that I should be able to build a small project like that (5 components, plus bits) so I went ahead to make a proof of concept:

BF-1 Butterfly (artwork by Petra Randewijk)

This is what the board looks like: transistor is a BC550C, diode a 1n4148. The sound is very dark and fuzzy, played with a bass guitar you get very nice bass synth sounds. Also, because the diode "steals" a lot of current/voltage from the transistor, there's a lot of gating going on and note decay is very fizzy. In a good way, though :)

BF-1: 0.1uF output cap, BC550C, 4.7uF input cap

BF-1: 100k resistor, 1n4148 diode, that's it :)

This is what the schematic looks like:

All in all a very easy build an highly recommended if you want to try your luck at soldering :) Also, using sockets for the transistor and diode add a lot of fun, because you can try different combinations, as you'll see in my next post..

If anybody's curious about listening to these pedals I made, I will soon start putting up soundbites here and there.

Building fuzzes, early attempts

Back in 2000-2002 I built my first fuzz. It was a Fuzz Face clone with BC109C transistors. As I had no previous experience in electronics, I was pleasantly surprised it worked at the second try (after I switched around the transistors a couple of times to get the legs lined up...)

The old 2.2uF Sanyo electrolytic cap probably wasn't the greatest idea for an input cap and with no clue about biasing transistors, the high Hfe BC109Cs are probably not running very efficiently (iCircuit tells me Q2 Vce=7.31V)... The schematic looks like this:

All in all this box makes a lot of noise, chokes on the low end, oscillates like crazy and picks up all kinds of radio stations, but it worked! Even the LED lit up, albeit not very brightly behind that 470k resistor..

About that LED, I only figured that I needed about 1.5Volts to get it to work, so I set to finding a resistor that would give me around 1.5Volts, no clue about Amperes... (iCircuit tells me the Voltage over the LED is in fact 1.383Volts) :-)

After this succes I decided to build another one, but it sounded whimpy, I figured I must've done something wrong, so I set to building yet another one, which didn't work at all, so I scrapped the whole DIY project and put everything in a closet for 12 years.

I did use this Fuzz Face a couple of times, but it kept breaking, because of crappy wiring, so eventually it got an early retirement..

Welcome

Hi folks,

welcome to the BC107 Love blog. I will be writing about my adventures in electronics, particularly about building Fuzz boxes..