Nazo Fuzz revised from gus's HP SI 2n2222 fuzz

[EATyourGuitar]

do you remember when Gus posted 2 Si NPN HP like fuzz

after a non-working perfboard build I decided to come back and breadboard it. the difference is that I now have a 100uF non-polar tantalum. electro wont work at all.


I didn't have a gain pot on the input but I did have a volume knob on the output. I was getting so much volume on the output and the voltage at the collector of Q2 was a little more than what gus posted in the original schematic, so I just replaced the 47K with a 100k. I was also getting tons of static or RFI unless I palm muted the strings. like what you expect from a really high gain pedal or amp. thats another reason for the swapping the 47k to 100k. the static was audible when the volume knob on my strat was 6 to 10 bridge position only, even when muting strings not playing . on the input I tried a 47k shunt, slightly less noise, 1m no change. then 15k shunt on the input and the noise is completely gone except for a little on the tail of the note. is this only a problem on the breadboard? can I eliminate the 15k shunt when I box it up?

second problem. with all the original caps its a bit louder in the treble. changing the 47n to 100n just gives me a mid bump. I want it to be flatter or a little more bass. I redrew the schematic with the Diodes gus suggested (1n4001). also gave it a catchy name. I'm using the TO92 package 2n2222

click for large view

final thoughts, I think I like the sound of it without the diodes but it is way too loud and not enough fuzz. it would make a great boost, slightly fuzzy boost actually. I want to stack two nazo's together but I dont have another tantalum cap right now. when I get around to it, I want to try like 75uF on the first input cap and 120uF or 220uF on the input cap of the second nazo.

I tried a feedback resistor from the out jack to the in jack and I like it. but there is no way to gate it when not playing. if anyone can help me figure out how to make a feedback gate, I will buy you a beer. this circuit is too much fun to leave it where its at.

[EATyourGuitar]

fixed a mistake on the schematic I posted earlier today. double check what schematic you are using

[EATyourGuitar]

click for large view, links to my flickr page where you can also view hi-res pics.

I have not verified the 2.0 yet. everything should work. its a runoffgroove buffer splitter with one side going into the V1 nazo. the other side feeds an LED that turns the feedback on when you are playing and shuts the feedback off completely when your not playing. without the feedback gate, you would have an oscillating tone that never shuts off. on the breadboard, a 330k resistor from before the volume pot going back to the input after the gain pot was all it needed to oscillate but you could still play and control it. the total resistance of the LDR at full brightness + the feedback pot should be set to equal 330k. when the LDR goes dark it will be about 300k to 1M plus the 300k of the feedback pot for a total of 600k to 1M3, dpending on what LDR you use. that should be enough to stop the thing from oscillating when not playing. if you build this before me, please let me know how it goes.

[EATyourGuitar]

there is a mistake in the old schematic, missing the +9v on pin 6 on the 386. I fixed it and reposted the corrected schematic above.

[EATyourGuitar]

the IN comes from the gain pot and the OUT goes to the volume pot. in the perf layout, C3 is connected to the lead of R3 which is connected to the emitter of Q2. this is a really tight layout and may not be easy for a beginner. all the components are flat so at least you dont have to worry about that. my 100n poly film's from tayda take up 3 holes exactly. I'm using SIP sockets for the transistors on this one but you don't have to. C3 is tantalum, I guess it is polarized by the markings on it but I hear no change in sound when I flip it around. aluminum electrolyte wont work but I dont fully understand why.

[John Lyons]

Interested...just watching 
Curious to hear what it sounds like.

[EATyourGuitar]

I'll try and get you a video demo. I'm just gonna send it out with the 9 knob fuzz factory to my video guy. I can tell you this though. without the diodes, its just a slightly fuzzy boost with a poop ton of volume. thats why I want to do two nazo v1's stacked up with different input caps to flatten out the frequency response. 47n input is too much volume in the treble range, 100n is better but still too much mids. if I stack up two nazo's I'll have 80n and 150n input caps for a flatter frequency response. it should get a good fuzz sound without having to cheat and use diodes. its gonna be loud though.

[EATyourGuitar]

pictures of the completed pedal

Nazo is Japanese for strange/mysterious. the 15k shunt on the input makes it wobble like a trem or a dieing amp that sags at random. without the shunt, its a more standard fuzz without the broken random sag thing. also has more bass, more defined etc.. the problem is that it is so high gain, it picks up noise. thats why I added such a small shunt. anything above 15k doesnt bleed noise to ground at all. I want to make another one battery only with shielded wire running to the switch so I can just remove the 15k shunt and have a really sweet fuzz. if you build it, try it without the clipping diodes, that makes it way loud and just a little fuzzy. you could also make it with shunt and clipping on switches. maybe a switch for different input caps also. this would be great as a pcb with board mounted everything.

[EATyourGuitar]

I just tried it with another fuzz pedal. the 15k shunt is doing something bad that makes the ground of all the pedals do weird things. the nazo was in bypass and it made the other fuzz pedal sag and wobble. I'm using two separate one spot adapters. its doing something to the ground and I'm not sure if its going to damage another pedal or a power supply. looking at the schematic, I wonder if the base being connected to the emitter through a 100nf and a 15k resistor is somehow bad. does this pass an amplified ac signal back into the input? it is also not protected by the input cap.

[EATyourGuitar]

4 switches in a DIP8 package for diode clipping options. without the diodes, this is just a really loud clean boost. I like a 2 knob pedal so having switches inside was the best option IMO. it fits on a 9 x 19 stripboard.