Just a variation of various Death by Audio circuits using reverse beta gain (reversed transistor gain). Initially I was messing with Fuzz War 7 transistor fuzz and eventually got it to work but it was unstable and the decay was very erratic.
Replaced the five first stages with the four first stages of Soundwave Breakdown since it's much more stable. Added a small 470pF cap across emitter and base to tame oscillation. Tonestack is big muff style with tweaked values with a treble bleed cap parallel with the tone control to the two revovery stages. Germanium hard clippers is russian D311 with quite low voltage drop (0,2v). And I found that MPSA18 worked much better than 2N5089 which sounds much bigger and has more sustain and pleasant decay.
And yes, it does doom.
Verified
Nice man will defo give this a whirl.
ReplyDeleteFyi i just posted and found in the requests of tagboardeffects the dunlop fuzzface. I modded one for a mate recently and it really suprised the hell out of me. Any chance of a cheeky layout?
Bookmarked! Will draw layout closer to the weekend for sure!
DeleteThis one sounds heavy as hell but I'm getting lots of noise. At the lowest filter setting it hums and then around 10/11 o'clock it starts to squeal and gets worst the more it goes. I used 1N270's that measure .25
ReplyDeletehttps://i.imgur.com/iaILaY3.jpg
https://i.imgur.com/pGNy8vp.jpg
https://www.youtube.com/watch?v=RxqP9fvkhNU
Using reverse beta WILL cause some noise,I've built a few and there is some hiss but not worse than some germanium circuits. It's the nature of the beast. By your demo it sounds like oscillation from feedback within the circuit? Make sure keep wires as short as possible since this is a very high gain circuit. Maybe you could remove the white wire going to lug two of Filter pot away from the other wires? And away from the jumper at the right side of the board. The board itself looks fine. Are you using MPSA18? You could try 2N5088 as well.
DeleteNo change with the wire tweaks. Removing the 18's and using 88's fixed the noise but took the fire out of it.
DeleteDo you have any diodes with lower voltage drop, say in the 0,15v-0,2v range. Beside clipping they clamp the signal to keep everything in check (sort of). You could try some Shottkey's if you don't have any germanium with that reads that low. Also you could try MPSA18 for Q1 to Q4 and 2N5088's for Q5 and Q6.
DeleteThe lowest drop I've got on some 1N60P's is .211 and .210 and it squeals with the 5088's. lol MPSA18's in Q1 and Q4 is Squealy Dan's greatest hits. I think this one just doesn't want to be my friend.
DeleteHow important is the low voltage drop? The lowest I can find from musikding.de that I'm sourcing from is 0,3
ReplyDeleteYeah, you can try those with 0,3Vd but noise could be an issue. If so, try increasing 470pF cap to 680pF-820pF.
DeleteFinally got around to making it. Works very well. Insanely heavy, never heard anything like it. Used two 1n34as that for some reason were ultra low, 2,1 and 1,9 respectively.
ReplyDeleteIt's hissy when idle in the test setup, but I tested it against the PcbGuitarMania Death By Fuzz (Fuzz War mk 1 clone) that also hasnt been assembled and it sounds very close to it, so I assume it's a grounding thing.
Is there any way to add the fuzz/gain trimmer of the Fuzz War and make it an external knob like the Death By Fuzz on this one?
Cool!
DeleteThe hiss is there because of the abused reversed transistors and if you cascade them six (or seven for the Fuzz war)thing is getting more hissy. I'm quite ok with it since it s not meant to be a hi fi circuit.:-)
The gain trimmer/pot from Fuzz War V1 basically is a ground lift for Q1. You need to take the collector of Q1 from the board, connect it to a 390 ohm resistor which is connected to one of the outer connections of the trimpot/pot. The wiper should be connected to ground. Stock value 100k is a bit much IMHO....10k-20k works better.
Yeah,thought the hiss was inevitable :) It doesnt squeal like the other guy here experienced.
ReplyDeleteI might just skip that mod and keep it stock. The filter - if you can even call it that! - changes the character a lot, and it's never gokng to be a versatile fuzz, haha.
In any case, thanks a ton for the layout. You oughta start a pedal company with all these creative mutants of different pedals. Beats all the YATS of the boutique world
Sounds totally awesome!!
ReplyDeleteI used 1N34A, MPSA18.
Little bit hissy when the filter knob pass 12 o'clock, but it's not so annoying.
Thank you for this great layout
This thing is mint - picked my highest gain MPSA18's and it roars.
ReplyDelete