flemming
Well-known member
Did I miss the big reveal? If you lost the post-it note with the details somewhere on the workbench just say the word and I'll come by and help look for it
Fuzz War V1 Question (Transister-related)…
- Thread starter Coda
- Start date
Coda
Well-known member
Well maybe if you stopped focusing on build docs you’d have more time…
owlexifry
Well-known member
apologies if this has been addressed elsewhere already.
i’ve been trying to dig through the forum and find if there’s been any update since this PCB was examined.
looking at the timestamp on the current build docs (2021) it’s unclear if the schematic has been updated since.
there’s some interesting discussion on this thread about the whole thing.
of most concern is regarding the alleged tone cap - 680pF - appearing over a silkscreen that calls for 4n7.
then there’s a ‘stable’ fuzzdog version that seems reliable to function, and appears to have a 220nF tone cap (perhaps to align with the rest of caps).
quite a range of variability for a tone cap
will the real slim shady please stand up?
Ginsly
Well-known member
Givin’ this a bump, as reading through Bellum MKI threads has me scratchin my head a bit… Didn’t realize it was so finicky! Like you, @owlexifry, I’m wondering what might need to be tweaked from what is currently in the build doc…
youngkong10
New member
Yeah I'm also still dying to know more about this. I've been to these bellum mk1 threads a few times over the years but I finally have everything and I'm about to build mine to ease some of my curiosity. Would love to see the results of the trace for closure though.
There's an article in the magazine link posted by @cbg342 (https://circuitpunk.neocities.org/) by someone at DBA that goes over how they used a current mirror to reliably emulate the unreliable reverse active transistors. Might make for an interesting daughter board...
BrainDrain
Active member
Any updates on this one? Curious to know how it turned out.
Chuck D. Bones
Circuit Wizard
Interesting, but it's mainly a thought experiment. Unless we use a quad transistor IC such as MPQ3904, then we're still going to have some unpredictable behavior because the Vbe and HFE of the transistors won't be matched.
Par for the course
