Death by Fuzz I (Fuzz War)

[Hexjibber]

Hey all, hope everyone is well!

Latest effort is a DBA Fuzz War v1 clone, the er, infamous 7 transistor version! I’ve always been curious about this version having built a couple of the 4 tranny Big Muff based version. The original circuit design seems to have got a lot of flack as well as a reputation for being temperamental, found this board from PCB Guitar Mania so thought I’d give it a shot!

It needed a bit of work to get the best out of it, namely using 2N5088s with similar gain, preferably the lower the better.

Anyway, the main thing is, I really like it! I wouldn’t necessarily call it versatile but if you like over the top raging doom fuzz then you might dig it!

Etched and painted with a dose of glitter spray, again!






Had a go at doing a demo vid too;

 

[Robert]

Very nice, I have a board for this on the way so that's good to know about the transistors. =)

That purple sparkle is purdy.

 

[Barry]

Good looking build

 

[Hexjibber]

Very nice, I have a board for this on the way so that's good to know about the transistors. =)

That purple sparkle is purdy.

Thanks! Originally I just chucked a random set of 2N5088s in, it worked but just seemed like there was too much gain going on and was getting a bit gated. After measuring them I saw I had a mix between 350 - 480 hFE. With the amount of transistors being used it seemed to make sense to go for low gain, fortunately I had enough in stock that were all around 350-360 and that seemed to yield better results.

Another part that makes a big difference is the cap that is tied to lug 3 of the tone pot, I’ve read values of anything from 4.7nf to 680nf so I tried loads, I settled on 220nf (which was also recommended in the build doc) as 4.7nf for example made it too mid scooped and quiet for me and 680nf caused the output level to be out of control. Definitely a ‘quirky’ part of the circuit! Someone with better electronics knowledge than me would likely be able to explain what is happening, I just went with what sounded right to me

 

[Ratimus]

Sweet looking build! [edit: and sounding. Am I going crazy, or did I hear Moldy Peaches at some point?] I had to look up the schematic; how can you not love seven transistors of doom!? That circuit has a Big Muff Pi style tone stack- it's a high pass filter on one side and a low pass on the other, with the tone pot controlling the mix. If the cutoff frequency of the HP is much higher than the cutoff of the LP, you get that classic mid scoop.

Increasing the value of that cap lowers the cutoff frequency of the high pass. If it goes lower than the cutoff of the low pass, midrange in the overlapping region comes through both sides.

Jack Orman has an article about making that tone stack more flexible: http://www.muzique.com/lab/tone3.htm . If you look at the "shift" knob on the Hoof/War Horse, it's an implementation of his idea. Interesting way of dialing in scoop or boost.

 

[Hexjibber]

Ah thanks, that makes sense now! I thought it was behaving in a similar way at certain points. There seems to be a few version of the v1 Fuzz War with quite wide variation in terms of caps used throughout so tbh I don’t even know if mine is accurate to the original but I like what this one is doing!

 

[Chuck D. Bones]

Sweet. Beautiful artwork.
I have been wondering about this fuzz. DBA likes installing transistors in upside-down. They still work like transistors, but the hFE is much lower. DBA must have hand-select the transistors to get them to bias correctly in this circuit.

 

[therockdontstop]

Sounds awesome, in a completely brutal way. Appreciate the demos. Gonna try my hand at etching based on your walkthrough as well.
How'd you do the sparkle? And is there a gradient in the purple?

 

[Hexjibber]

Sounds awesome, in a completely brutal way. Appreciate the demos. Gonna try my hand at etching based on your walkthrough as well.
How'd you do the sparkle? And is there a gradient in the purple?

Thanks! Thought this one was worth doing a demo for as not many about, particularly DIY versions. Definitely give the etching a go, can take a few go's to get it right but really satisfying when it comes out good!

The sparkle was this stuff (link): Montana Hologram Glitter Spray

Just got to try and resist the urge to use it on every build now haha!

Good spot! I did indeed do a gradient, purple to black, the knobs ended up covering most of the fade up so it's pretty subtle!

 

[Nostradoomus]

Pro tip: Experiment with etching on your bottom plates! Wish I woulda done that

 

[Mir9]

That's a great sounding demo. Do you find the voltage starve trimpot they added useful, or would one be fine leaving it out?

 

[homeoffice]

I just built mine and it has significantly lower gain than yours. If I crank the gain it's kind of similar (still a bit lower I think), but the first 3/4 of the fuzz pot is more medium distortionish. Not quite as thick as yours on the lowest setting, too.
Also, the volume boost on the tone pot is massive. Especially in the last quarter it gets loud as hell.

Ideas?
My transistors are more or less matched hFE around 250.

 

[Hexjibber]

I just built mine and it has significantly lower gain than yours. If I crank the gain it's kind of similar (still a bit lower I think), but the first 3/4 of the fuzz pot is more medium distortionish. Not quite as thick as yours on the lowest setting, too.
Also, the volume boost on the tone pot is massive. Especially in the last quarter it gets loud as hell.

Ideas?
My transistors are more or less matched hFE around 250.

I used 2N5088s which were all around 350-370 so I would expect would explain the difference in gain, but with this janky circuit who knows?! Yeah I found the same with the tone pot, not exactly refined is it!

 

[homeoffice]

Thanks for your answer! I'll try some different 2N5088s!
edit: switched those I had in there to a set of 290-320s (those were the highest rated I had here) and voila! --> more gain!
That was easy... Thanks again!

 

[Bobbyd67]

Thanks for your answer! I'll try some different 2N5088s!
edit: switched those I had in there to a set of 290-320s (those were the highest rated I had here) and voila! --> more gain!
That was easy... Thanks again!

You might wanna try some 2n5089, it's basically a higher gain version of the 5088

 

[homeoffice]

You might wanna try some 2n5089, it's basically a higher gain version of the 5088

Good idea! I'm going to get some, try it out and report here.