My First Fuzz...

[eatyourguitar]

Beep happens when the probes see a resistance < 50 Ohms. I think your probes are shit or dirty or oxidized. No need to buy probes though, we can work with this. I know your probes can get down to 49 ohms cause you made it beep once. Disconnect the power from the circuit first. The test a resistor anywhere and see if it gets close to the value marked on the resistor. You can check continuity with the meter set to resistance (ohms) and just look for < 100 Ohms manually with eyes on the meter.

[HighDeaf1080p]

Thank you!! I'm sure I will be getting new leads at least, and maybe a Fluke 113 to go with this cheaper Vici VC99 eventually. Then I can just use the vici for current measurements if I ever need to, and for measuring HFE on transistors.

At any rate, I just added the clipping diodes this morning, and i'm pretty pleased. Seems like everything got pretty darn dirty with those in place, so now I'm not sure the 3904 is too low of gain after all...especially since I'll be feeding this output into another gain stage. I don't think there's any way I can max out the knobs on the elektra side, and still have anything cohesive once it goes through the Bazz Fuss section I'm about to build.

Definitely going to want to put the clipping diodes on a blend pot as I planned, cuz I really like the loose flubby sound of the elektra without them, but with them, I'm in love. After a ton of swapping and reorienting, I think I've decided on a pair of 1n4001's in opposite directions, and then a switch to bring in a 1n270 oriented negative towards ground. I really liked the cleanliness of the 4001's doing symmetrical clipping...but then adding that 270 gave everything such a slippery, plexi-glass gurgle, like running your finger on a wet soapy plate. My, my, my.

I have to fight the temptation to just box up what I have before I at least try adding the Bazz Fuss half. It sounds so good, I'm just scared of diminishing what I have...but I have to remind myself that I can always leave off the Bazz Fuss when I go to circuit board if I can't see any improvements...and with my current knobs allowing me to turn the Elektra side all the way to clean, it seems I'll have a wide spectrum of sounds coming out the back end of the Fuss. Might even be able to get the MPSA13 biased similarly so I can make that stage totally clean if I want, and just have my current product sailing right through.

[eatyourguitar]

I was never impressed with the bazz fuss on guitar. it was a waste of time I think. on bass it depends what you use to build your bazz fuss. there are many variations around the internet.

[HighDeaf1080p]

Ok it's all on there and sounding gorgeous. Now just a few more parts to audition for changes. Then I'll mark up and draw the final schematic with the final parts.

Then it will be time to decide how to transfer it to a board and box it up. I'm really surprised at how good it is sounding, even just on a breadboard. I hadn't expected this big of a reward the first time out.

[crochambeau]

My advice is: once you have it sounding good on breadboard: LEAVE THE BREADBOARD INTACT AND ALONE. Build it on a board, for sure, but until you have the build recreated leave the breadboard up so you can direct measure stuff like voltages, etc...

If I had a nickel for every time I read "it sounded great on the breadboard but then I must have broken something transferring that to the enclosure"

Nice clean work surface! Curious if you can manage keeping it that way, hahaha.

[eatyourguitar]

The breadboard also has accidental schematic changes that you may have missed. If you take it apart and throw the resistors in a bin, you might not notice a different value resistor was substituted. If you have germanium on the breadboard you pretty much must transfer those transistors or give up on cloning that sound. Silicon it doesnt matter.

[HighDeaf1080p]

Is that just with transistors, or does that go for germanium diodes? I have one germanium diode (a 1N270). Everything else ended up silicon.

[eatyourguitar]

All the germanium diodes have the same gain and that is 0. They are all the same because the properties of doped germanium govern the forward voltage of a single PN junction. They are interchangeable and that is a good thing if you are a manufacturer using hard to find parts. If you have a curve tracer you can investigate if the germaniun diodes are consistent with others or are they special and rare.

[HighDeaf1080p]

Here's the current state:



I'm wiring up the clipping section like this tonight, testing the different capacitor values on input and output caps, and if everything goes well, I'll be ordering my parts for the permanent build tomorrow. Woot woot!

This doesn't look so bad. Billions of wires running to pots, but otherwise, it looks easy enough for me to handle...assuming I got it right.

[HighDeaf1080p]

SUCCESS!!! The clipping section seems to work perfectly, with a knob that goes from fully silicon symmetrical distortion all the way to the left, to fully germanium/silicon asymmetrical distortion all the way to the right...and a smooth transition of every combination in between. LOVE IT!!!

Parts are ordered for the permanent build, and extra bonus: Once I build the stripboard version, I'll have all the parts needed to quickly build a second one. Woop woop!!!

Thank you guys for all your help. If I run into any problems during the soldering part of the project, I'll report back, otherwise, I hope to post a completed pedal with sound clips, etc. soon!!! Wish me luck!

[culturejam]

Man, that's a lot of gain controls for one pedal.

[HighDeaf1080p]

Haha, four of 'em and they all go to 11!!!



Inject: Controls how much input signal hits transistor 1
Aggitate: Controls the gain of transistor 1

These are similar controls, but the sound of Inject at 10 and Aggitate at 3 is definitely different than the sound of Inject at 3 and Aggitate at 10. You have the added bonus that you can use the inject control to "set the range" of Aggitate, and vice versa.

Graft: Controls how much distorted and possibly clipped signal hits transistor 2. This creates a wider range of differences because such a wide range of sounds are going through it based on earlier knob settings. A subtle gurgle from earlier stages causes graft to behave much differently than sizzling cranked grind. It's basically setting the ratio between the two gain stages and the clipping stage in the final product.

Incubate: This is the most interesting of the 4 gain knobs. This one at low settings causes the sound to squelch out to a low volume right after the attack...it creates a pizzicato effect that doesn't die out completely, but sustains for a bit of time at a pulsing low volume after the initial swelled attack. At medium settings, you start getting crackling vecro static on the notes, particularly on the decay, but the volume swelling/pulsing stops. At high settings it brings on the hiss of white noise like a knife blade. I'm really praying that when I get the permanent board soldered up, all these behaviors stay, and its not just due to some mistake or problem on the prototype, but everything seems so stable on the breadboard right now. When I swap things around, or move parts of the circuit, all the behaviors and sound stays, so I'm feeling pretty good about it. Only oddity is that it seems to only get to working this way after 30 seconds or so of warming up. Not sure if that's the germanium diode in the works or what. Maybe all my pedals are that way and I've just never noticed because their effects are less pronounced.

Given the vast range of output volumes from the various settings of the 4 gain knobs, the "Magnify" output volume control gets quite a workout.

The "calibrate" knob that warps the waveform from symmetrical clipping to asymmetrical is just super. The B50k pot in the clipping section was just the first value I tried, and it sounded so good I didn't bother auditioning a 1K, or 10K or anything, but its possible something else sounds even better. It just didn't seem to me that the value of that one would matter much, given its function is just to fade signal from pin 1 to pin 3, and both paths go through a diode to ground.

I couldn't be happier with this fuzz pedal, as long as everything goes well in the transfer to circuit board from bread board, and it still sounds the same. Working with dminner on a badass enclosure design.

Minor addition of LED and protection:

[HighDeaf1080p]

So the schematic I stole the LED protection from had a 22uF capacitor before the resistor. Can anyone tell me if the capacitor's value is critical in any way. I only have a 10uF in my hoard at the moment. I'm expecting that the capacitor is only there to ease the speed of on/off...is that correct?

I assume the 4.7k resistor is what's actually protecting the LED, and changing the value of that determines how bright or dim the LED is...

[crochambeau]

Yeah C6 is just filtering high frequency out of the power supply, R7 is current limiting the LED (your so called protection). 10u is a fine value for filtering, though you find it may not be critical, it is certainly not doing anything for the LED (aside from maybe shunting the LED noise I hear people talk about but have yet to notice or be bothered by).

[HighDeaf1080p]

Ah, I see. Thank you! I'll stick the 10uf in there and be done with it then. Yea, I was calling it LED protection because, while I don't really care how bright the LED is, I do care about the LED burning out quickly, which I understand will happen if you don't use a resistor or some kind.