Thunder Fuss - A BtR Original

BuddytheReow

Breadboard Baker
This is another one of BuddytheReow's "originally" designed circuits and is more involved than my last build, the Heavy Devi. The heart of the circuit is a Bazz Fuss which does the clipping. You can read about this most latest version here. I need to update the daughterboard layout since I realized I made the layout incorrect. I will update that shortly.

Anyways, first is a PREGAIN control which throws some input signal to ground and the tone doesn't change in either direction. Then a BMP input stage to act as a boost. The "GAIN" pot on the BMP is the STARVE control here and gives that velcro sound when the signal is barely going into the Bazz Fuss stage. This then goes into the Bazz Fuss with selectable diodes and a Bias control. The diodes range from a Schottky 1n5817 through a Blue LED in terms of voltage drop. I went boutique-y with this and used a MPSA13 as a diode just to say I did it fancy, haha. The larger the voltage drop (LED side of things) the more "open" this sounds. Think less compression and clipping here. Higher voltage drops gives a more distortion vibe and smaller voltage drops give a more fuzz/buzz vibe. This then goes into an active Baxandall tone stack and then a volume control to output.

It's a glorified Bazz Fuss.

Boxing this up was the most time consuming, but I had the most fun here. My workbench looks like I spilled sprinkles everywhere. I think my offboard wiring is getting better compared to some of my other stripboard builds. I said better, it's not great yet.

I'm not 100% sure on the knobs or the enclosure art. I decided to box this up after really playing through it for about a week and decided I was happy with it.

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Dude this makes me want to build a circuit off of strip board! Love the guts! Sick build!
Stripboard definitely gives off the true DIY vibe and there's a great feeling of knowing you made a circuit start to finish from scratch. It is easy to work with and very forgiving with your soldering iron. Theres a stripboard thread in the Test Kitchen to get the info you need. The downside is that they can get very large depending on the circuit and the offboard wiring can get messy if you're not careful. PCB builds are much sharper looking and more compact. IMO it doesn't matter what it looks like as long as it sounds good since you won't see the guts when it's all boxed up.
 
The DIY part is why I’m here not saying I’m that advanced yet but I def want one under my belt and if I’m going to be doing this of course I have to mod it haha
 
DAM Meathead and Dr Tony balls 1966 look like easy enough circuits might start with either one….I’m going to keep this as a future project!
 
Finally finished the enclosure, but I did spend a lot of time with this on my board. The 'Fuzz' control is just the diode selector. When I get into the germanium territory, it's a little too compressed and quiet for my taste. I think where this one shines is in the LED and transistor territory for clipping. Since it's a fuzz, the best way for me to clean up the treble portion is to throw a Rat in front of it with the gain turned nearly all the way down. I'm very proud of this one since I basically pulled it out of thin air with a little help from this site.

Anyways, I hope one of you builds my tasty creation and can compare.

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Hey Sandy,
I was looking at this one again and I wonder if R6 is really 220K, or something smaller? Is STARVE 50K or 500K? Just seems to me that R6 should be smaller than STARVE. I'll have to breadboard this and find out.
 
Hey Sandy,
I was looking at this one again and I wonder if R6 is really 220K, or something smaller? Is STARVE 50K or 500K? Just seems to me that R6 should be smaller than STARVE. I'll have to breadboard this and find out.
STARVE is 50k and R6 is 220k. 220k seems really high, but thats the value I ended up with. Fully CCW I wanted the signal to barely make it through the clipping stage to give the "starved" sound. Anything lower than that and the signal dies out.
 
I ran a sim and it looks like you nailed it. R6 & STARVE alter the bias on Q2+Q3 by just the right amount.

You don't need R1; the PREGAIN pot performs the ant-pop function.
 
I ran a sim and it looks like you nailed it. R6 & STARVE alter the bias on Q2+Q3 by just the right amount.

You don't need R1; the PREGAIN pot performs the ant-pop function.
I thought 100k wouldn't be enough to prevent popping. Most schematics I see have a 1M or no pulldown resistor. I guess it's overkill here.
 
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