bias? schmias!!

[pinkjimiphoton]

i finally figured out how to reinstall the original video software, so i gotta redo this when the little woman leaves in  a bit.

one of the cool things about this that i couldn't show off last nite is the attack of this. at full fuzz you can achieve too much distortion.

it's almost like an envelope follower.. it's like if you whack a power chord hard, you get this crack of pure fuzz that then swells into this nice huge gated buzzy squarewave thing.

it's not for everything, and not a fuzz i would go-to all the time live, but if you like buzzarrounds and buzzboxes and such, crossed with a superfuzz kinda sizzle, it's kinda cool.

right now i am working on trying to find some boxes, cuz i don't wanna waste a 1590 on one of these. for stuff for me i like them rat shack boxes.

[pinkjimiphoton]

i just found this, looks kinda similar



this page seems to sum up this kind of circuit, and it's limitations.

the cool thing is what it does to your attack...

http://www.st-andrews.ac.uk/~www_pa/Scots_Guide/audio/part2/page1.html

[pinkjimiphoton]

revising this again. sounded a bit different boxed than on the breadboard.  changed the contour control to a tone control, can eliminate the .001 cap for it.
got the diode in the power supply backward as shown too.    brain dead...

gonna add the little booster stage that led to this to the front end and see what i think. i tried it after this and liked it but before it i liked it a lot more.
sorry for any inconvenience... stay tuned.

[bwanasonic]

stupid pedal trick... it works!! i really dig this thing...

and the vero above is verified!

I really like the spectrum of clean to dirty, and I got an idea of what it does to the attack. I have a bunch of Raytheon high-gain germanium (T59247-6416) that I'd like to try in this circuit, but maybe they'd be too high HFE.

[Gus]

i just found this, looks kinda similar

Jimi
that looks like a FF type circuit with a input blend.

[pinkjimiphoton]

yeah gus that one is... first thing i noticed was the lack of biasing resistors. it's not the same as my circuit, but explains maybe some of why it sounds the way it does.
skip back to earlier in the thread to see my schematic i worked up.

kerry, i tried some good ge's in there last nite, and it made me crazy for hours. it won't bias up unless the leakage is fairly signifificant. i could not hit unity gain with decent transistors, this sis strictly for crummy ones... which was my intent, to find a way to use garbage ge's that we all seem to have.

this drove me nuts last nite too cuz i lost volume when i boxed it...very weird!!

i am gonna build this: http://www.diystompboxes.com/smfforum/index.php?topic=105637.0

as a front end for this i think. i'd originally tried it affter the fuzz, but in this case, before the fuzz sounds great,  and pushes it just above unity.

the other thing with this is run it different from what you expect... crank the volume, and turn the attack all the way down, then bring it up til ya hit the desired level of filth. the last 1/4 turn of the attack knob will take it from overdrive to distortion to fuzz to velcro ripping pitched static. full blast, if ya whack your guitar, it will sag then swell in. it's kool!!

[pinkjimiphoton]

i built a tiny daughterboard.

there's a 100u cap for a filter, a 100k trimmer on c, e to ground, .0047u chicklet to base from switch, and .047u cap off c to input of attack pot.

wow. total difference. it's now a much more useable fuzztone, and it cleans up somewhat depending on how you set it.

very sweet and vintage sounding, like a little tweed ampular about to explode.

ya know that sound just before it's ghost comes out in a puff of smoke from the tiny voice coil you just abused you filthy amp destroyer, you.....

whoa.... lost my mind there for a minute.

i gotta draw the schematic AGAIN, and scan it.  but i think i got one that's kinda cool this time guys.

i even tried it in my clean fender twin, it sounds like a cross between a big muff pi and a superfuzz, but smoother. once my kid and brother get up i'll try and catch a little video loud enough where you can hear it.

and i'll bring the volume below unity on the fuzz so you hear the effect, not the amp.

peaaaaace...

[pinkjimiphoton]

OK....

here's a schematic (sorta)/pcb layout.

this is built (on vero) working and sounds really good... very very vintage sounding kinda distortion with ridiculous sustain.

if ya build this, start with the attack all the way down when you try it...  crank the volume and tone full, then bring upo the fuzz til it's good.

full attack should be noise. like... tuned noise!! below that are a lot of good tones tho.

i think i can stick a fork in this one finally!!!

i will try and draw a schematic to upload soon, and a vero too.

peace!!!



extra pads are for adding biasing resistors if you decide you need them for some reason.

this is the Liberal Komrade Boost (lkb1) (minus gain pot) slamming the previous version of this fuzz. now calling it the ancient prophet cuz it sounds like the 60's.

video soon, too. in sync, even.

[pinkjimiphoton]

stupid pedal trick... it works!! i really dig this thing...

and the vero above is verified!

I really like the spectrum of clean to dirty, and I got an idea of what it does to the attack. I have a bunch of Raytheon high-gain germanium (T59247-6416) that I'd like to try in this circuit, but maybe they'd be too high HFE.

kerry, where are you?
if you wanna pm me your address, i can send ya a few of these low gain old ge's to experiment with.



i got invited out last nite to a nice little juke called the hungry tiger here in manchester to play with my friend's power trio. i hate just sitting in on someone else's gear, so i tend to grab a fuzz an amp and a couple cords.
last nite i grabbed the ancient prophet after a/bing it with 5 or 6 other fuzzes i had handy (not the ones on my pedalboard).

guitar was a jay turser 134dc that i sniped two days ago on ebay to replace one my wife had gotten me that was lost to the sands of time.

amp was my cyberdeluxe, set on my usual setting (a clone of the princeton i'd built with a touch of tape echo)

i found this circuit had plenty of volume and balls on tap.

i like the gain pot at about 10:00 or so, and the volume juiced. too much gain  will lead to pitched ripping velcro fuzz with some serious sustain, which wasn't what i was looking for.

this way, when i turned my guitar up i gotta real nice crunchy sustained distortion, and as i turn it down it cleaned up.

did the last set with them, just the plank, the fuzz, the amp, 6 strings and an arsehole to drive 'em and it was great. i was really impressed, which i seldom am
once i try something live.

it's an overdrive/distortion/fuzz all in one depending on how you set it. and seems to have plenty of output.

if anyone dares trod this path... let me know.

i'ma gonna work up a vero and proper schematic. as soon as i get a time without a house full of peeps, i'll make a video.

[pinkjimiphoton]

here's the schematic for this thing.
guess you guys are sick of fuzzes.

some poor guy will discover this some day tho, and be like..... "yeah..."

[Cozybuilder]

I look forward to building this one too!! Check the polarity on the diode and filter cap in the power circuit.

[pinkjimiphoton]

good catch. brain dead.


so... 1n400x needs to be reversed in polarity as well as the 100u cap.

my apologies, just realized i'm looking at this backwards from what i was thinking.
so used to drawing pos on top, neg on the bottom.... :oops:

so the cathode always needs to face the voltage potential, irregardless of polarity of the circuit.

please, if ya mess with this, adjust the schematic/layout etc accordingly

thanks delta fred, box, and cozybuilder for catching this mistake!!

i may have to revisit some of the other pnp's i'd built that had "issues".

[pinkjimiphoton]

remember too this isn't a crank the gain to 10 and leave it there pedal for most peeps.   

if ya test it with everything full, expect it to sound bloody horrible in a kinda cool way.

i'd start with the attack all the way down.. it will still overdrive like that cuzza the small resistor between pin 3 and ground.

start with the tone about 1/2 way up. i'd changed it, so it really only seems to do anything thru the first half of the sweep (you can make it a contour control, add a 1n cap to ground from pin 1 of the pot if ya want a little more tweakability, but it puts max treble near the center of the pot rotation, which i liked but found counter intuitive.

with your amp cranked up to a normal playing level... maybe not stadium volume, but at a volume you'd actually use it at ... turn it on and turn the volume up.
you should hear the effect come up immediately. crank it up to unity gain. or go past unity gain if ya want. the higher you go, the more distortion you'll get, it's fairly interactive with the attack pot.

now start bringing up the attack until ya get a decent fuzztone. you should be able to twiddle from fuzz to cleanish from your guitar smoothly... at least thats my way to do it.

that'll probably be, if you were looking at a clock around  10:00 on the attack,  1:00 on the tone and maybe 12-1:00 on the volume. should give you a decent useable range with a bit of a boost to it.

into a cleanish amp it sounds to me when the fuzz is cranked almost a univox kinda sounding fuzztone, and you can get that tuned static thing going fairly well. it's more jagged and harsh with the guitar up, but sweetens up when ya turn the guitar down.

into a cranked up edge-of-breakup kinda amp, it's smoother and darker and it makes the cream come out of it.

in the live video, you can also hear what it sounds like into a hyper distorted amp (if ya notice something clam me up, and reaching for the guitar knobs that's why... the sax player had brushed my amp's patch selector knob, and changed me from my normal princeton to a boogie-ish patch.).


objectionable hiss may or may not be an issue depending on individual transistors. i found i could dial in "sweet spots" that would be less hissy and still produce decent tones over a range of transistors... as long as the gain is really low they all seemed to work. you may need to examine your pinouts. i've found that often with these transistors, i just try them socketed in normal or reverse beta, and use whichever polarity sounds best. sometimes they have more-- or less--- gain that way. sometimes one normal and one reversed also seemed to help with the noise some, wondering if it was via phase cancellation.

you can also put a smallish cap from signal to ground on the output pot to help tame hiss. this is no worse than any marshalls i ever owned (ie: when you stop playing, you WILL hear some ocean, but it's masked when you're playing.  even the crummy noise gate on my cybers can deal with it)

things to play with.

i never ever used to do it until just like LAST WEEK even tho i've had it for years, but i would advise using a breadboard and trying this before committing to a build.

that way you can play with cap values etc.

something to ponder... most people seem to so far like a bigger cap for the input. you WILL get a LOT more fuzz that way.

but as you add stages, it will get unstable and motorboat possibly, leaving you with weird voltages and an aching bwain. and farty, gated, nasty, buzzsaw kinda fuzz.

however, if you go SMALL... 1-10n max on the input, and imho the smaller the better (but not below .001u) the sweeter the entire beast becomes. you get more guitar signal thru the crucial
first stages with less waste in bass frequencies you don't even have.. and then as it comes out of stage 2, the big-ass 470n cap lets enough of the subs generated by the first two stages of distortion and it starts to phatten up again. after the final stage, it phattens up more... and you lose most of the farty buzzy stuff. (good, imho) and it starts sounding almost muffish with a sweet sustain and weird almost envelope follower effect.
you can effectively tune the overall gain of the circuit by how much bass you wanna let thru.

while you ARE dispensing with it going in, as you fuzz the signal, you add harmonics and sub harmonics..so you're replacing some of the original frequencies with for all intents electronically synthesized ones, which i think may be part of why it sounds the way it does.

lean in, and it cracks. back off, it smooths down. whack it and it overloads (at some settings) and swells in.

there's more going on than i am even on the dawn of comprehension of.

[pinkjimiphoton]

update: forget this (apparently) with npn transistors. either they won't work correctly, or the ones i have are "too good".

shitty, crummy pnp's sound great. none of the npn's i have sound even remotely decent. <shakes head>