presenting the Schizoid Face

Original effects with schematics, layouts and instructions, freely contributed by members or found in publications. Cannot be used for commercial purposes without the consent of the owners of the copyright.
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Post by pinkjimiphoton »

if ya want about the same volume between the two sides on this, try a 390 or 470n cap instead of 47n

only install the snubbers if you have to, if it's hissy they can help, but if it's not its better to leave them out. the smallest possible values you can find that work are good..
100pF is a LOT of highs gone. 22-47p may be better. but like i said, on mine, i just leave 'em out, and the ones i had already built i just cut 'em right off the board. adds a bit more harmonic sizzle to the top end... in a good way.
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Post by Ripdivot »

Thanks for the cool project! I breadboarded this up with several transistors between the 175 and 225 hfe range. I found that it cleans up good but not great with any of them but the fuzz tone is nice. I have tested all the other components and they are all good. As someone else mentioned a 10k pot in place of the 8.2k resistor really opens the pedal up. I find that if I roll the guitar volume down to about 6, I can use the 10k pot to get the most out of the clean up. It always seems to sound best between 5-6k. The mids are thicker and it cleans up really well. It really gives you a lot of tones...

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Post by Manfred »

Hi bro.

You mentioned above as follows:
final revision of this particular circuit.
change the .047 cap (c1b) to .39
add a 50-150p snubber cap between c and b of q2
The changes do not appear in the last release of the schematic.
if ya want about the same volume between the two sides on this, try a 390 or 470n cap instead of 47n
Which one do you mean, C1b or C2?
Please tell me the current values. :secret:

I intend to modify the PCB in line with the recommendations as follows.
Omit the 4.7M resistor.
Make the snubber cap switchable.
Replace the 8.2K replace by a 10k pot.
if ya want about the same volume between the two sides on this, try a 390 or 470n cap instead of 47n
Make this cap switchable too.

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Post by pinkjimiphoton »

Ripdivot wrote:Thanks for the cool project! I breadboarded this up with several transistors between the 175 and 225 hfe range. I found that it cleans up good but not great with any of them but the fuzz tone is nice. I have tested all the other components and they are all good. As someone else mentioned a 10k pot in place of the 8.2k resistor really opens the pedal up. I find that if I roll the guitar volume down to about 6, I can use the 10k pot to get the most out of the clean up. It always seems to sound best between 5-6k. The mids are thicker and it cleans up really well. It really gives you a lot of tones...

you don't likely need the 10k trimmer on q2. crank the fuzz and volume full, and control it from your guitar. should clean up perfect. of course, "clean" will be maybe 1 or 2 on the guitar... from that point on, you can turn your guitar up and get any shade of dirt you can need from clean to crunch to scream.

i don't care for trimmer pots in this circuit. ya'll are free to add them if you need to.

if the mids ain't thick enough, use a bigger cap for the input on the photon face side. the original value i used for that was indeed 47n, and it cleaned up nice but was too thin on some of my strats, but nice on my les paul.

so i went up an order of magnitude 10x and increased it from 47n to 470n (or 390n, whichever i happen to grab first, the sonic difference is almost indistinguishable at that point between the two) and that gave it plenty of fat.

when my guitar is barely on, and the schizoid is cranked full, it sounds exactly the same as the guitar about half way up with the fuzz off, but a little more compression.

if you have the volume below full on the fuzz, yeah, it will sound exactly as you describe. try it pegged and do it all from the guitar, and i bet you won't need the trimmer.

to make a confession, some of 'em i build with 2 27 ohm resistors in series instead of the 47ohm specc'd for q2. this one resistor can change the tone and response drastically. if you go 27 ohms, it's fuzzier and harder to control. 33 ohms is better, 56 ohms and above and it begins to lose the clean up it should have. 47 is ideal, but 54 (27 an 27 ) is still close enough to pull it off.

them stupid low value resistors are what let the rest of the circuit be a classic standard fuzz face.


its funny, here you guys like it, over on the other forum all i got was shit about it from people that know better. i'm like .... breadboard it and tell me i'm wrong. nope. all i hear is "well, you shoulda done it this way like me"... except i've built or breadboarded most of their circuits, and they all fuzz, but none of them sound or clean up right.

the thing in common is they all try and bias the q's with the c resistor. that's fine, but to control the gain, you gotta fuck with the e to ground resistance. totally changes the whole fucking thing.

peeps are butthurt cuz i said it don't suck. life's a bitch. it don't suck. if some folks can't deal with it, whatever. breadboard it and then tell me lol

either they ain't trying it, or they are and discovering it does sound and work good but won't admit it. i'm imagining they know better over there than to try it. their loss. :mrgreen:
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Post by pinkjimiphoton »

Manfred wrote:Hi bro.

You mentioned above as follows:
final revision of this particular circuit.
change the .047 cap (c1b) to .39
add a 50-150p snubber cap between c and b of q2
The changes do not appear in the last release of the schematic.
if ya want about the same volume between the two sides on this, try a 390 or 470n cap instead of 47n
Which one do you mean, C1b or C2?
Please tell me the current values. :secret:

I intend to modify the PCB in line with the recommendations as follows.
Omit the 4.7M resistor.
Make the snubber cap switchable.
Replace the 8.2K replace by a 10k pot.
if ya want about the same volume between the two sides on this, try a 390 or 470n cap instead of 47n
Make this cap switchable too.

sorry brother manfred,
yeah last revision i added all the switching and shit, didn't remember to remove the zero from the input cap. one side should be the standard 2.2uF (photon face) the other side (stupid face) stock uses a .047. it works and sounds nice.
but i prefer a 390 or 470n cap instead. c1a should remain at 2.2uF. c1b stock is .047, but i reccomend 390-470n instead, as it adds about 2 octaves more of bass. and thickens the fuzz up if it's two thin. in other words, i use 390 or 470 on my own personal builds, whatever i grab first on my bench. my preference is 390n, but the difference between 390 and 470 is pretty slight. .047 to 470 is a much more noticeable change, may be worth adding another switch for some people.

i DID try the "fake variable cap" thing with a pot and a couple caps but it was pointless and made no difference in the tone of the circuit other than robbing gain. that's why i made it switchable in the first place. it started with the stupid face. then i tried the same circuit with the more standard values and that became the photon face. putting 'em both together in one circuit (as it's really the same just a couple component changes that alter the sound drastically) became the schizoid face.

you can leave the 4.7m anti pop resistor, it's fine. i just use it differently, cuz the board you layed out won't fit in a 1590a. but it's perfect just the way you have it brother.

so in summary

c1b can be anywhere from .047 to .470n. i'd socket and experiment to see what you like best. if ya bought one from me, it would be 470n.

ditch the snubber cap, but i'd leave the holes for it just in case. mictester said in his build he added them between b and c of both q's. i found them unnecessary.

leave the 4.7m anti pop where it is. should be fine.

really nice layout. ass load of offboard wiring for sure!!!

but the lite show is kinda cool if ya wanna add it. photon side the smiley face lights up with green leds, stupid side with blue (just two, depending on which side you choose) and in bypass they all four turn red.

use a 27k or 33k current limiting resistor for each pair of led's. if ya use the tayda rgb's with a common anode like i do, left to right, with the longest lead being #2, it goes

red, anode, green, blue. the only other thing i'd suggest is running the CLR's right to the power supply jack, as they don't need filtrering really.

hope i didn't make shit more confusing.

ditch the snubbers

use sockets and try .047. then try .47. see what ya prefer

leave the 4.7m resistor

crank the motherfucker full blast and control it from your guitar.

you may find you can get away with turning the fuzz and volume down slightly, but like the real mccoy it wants to be pegged.

full fuzz full volume will giove you the most dynamics and touch sensititivity and best tone in my experience on any fuzz face circuit.

let the guitar be the volume and tone and pregain as it should be.

and i think you'll diggit. i gotta build some up this week, i'm sold out again... but will try and get some video of the full gospel circuit recorded for you guys.

hope this helps,
peace!
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Post by pinkjimiphoton »

manfred, i'm an idiot :applause:

yeah, absolutely, make the smaller input cap side switchable. it's worthy of a switch. at .047 your guitar can JANGLE when the fuzz is pegged and the guitar is way down.

i do it all with just two stompswitches, but each switch could be its own really, and give you a wicked crazy versatile fuzzface.

on mine, one is standard true bypass, and the other switches the input caps, the led's, and the location of the ground for the fuzz from before the 100ohm resistor to directly to ground (it makes a difference... when ya put a cap into a resistance to ground like that, it becomes a filter as well as a fuzz amount pot in the case of this circuit)

i think it's worth it. i am very psyched you guys diggit. rock on!
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Post by Ripdivot »

Thanks for your response Jimi, and no you certainly do not suck! I would be very interested to see what your thoughts are if you try a 5k6 in place of the 8k2? I do leave the fuzz pot full up on mine and control it from the guitar. I find with the 5k6 the cleans are cleaner but there is a big difference between 10 and 7 on the guitar volume pot. I use a full sized pot for the 10k to be able to control it at any time, I'm not a fan of trimmers inside either...

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Post by Manfred »

Hi brother Jimi,

thanks a lot for giving exhaustive informations.
. i just use it differently, cuz the board you layed out won't fit in a 1590a. but it's perfect just the way you have it brother.


How large does the board have to be?

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Post by pinkjimiphoton »

Ripdivot wrote:Thanks for your response Jimi, and no you certainly do not suck! I would be very interested to see what your thoughts are if you try a 5k6 in place of the 8k2? I do leave the fuzz pot full up on mine and control it from the guitar. I find with the 5k6 the cleans are cleaner but there is a big difference between 10 and 7 on the guitar volume pot. I use a full sized pot for the 10k to be able to control it at any time, I'm not a fan of trimmers inside either...
i did mess with the biasing like that, and have build most of the fuzzes in the past with a 10k pot (as big as 50k with some transistors) instead of the 8.2k, and yeah, it can work fine. but when i was dicking around, i was looking to make the circuit as small as possible on vero. i could get it even smaller on perf, but cuzza that i wanted fixed resistors. so i tried the stock fuzzface values... and it came to life.

a higher voltage there, like with a kk6 would definitely make it cleaner louder and more overdrivey. you can dial it in beautifully for a lot of sounds that work great for sure.

i think the key is floating the transistor... by adding a SMALL resistance to the e to ground, you can limit the gain somewhat. i suspect there's something to do with ohm's law and the increased resistance of the transistor, but i havent figured it out yet. it has to do something ... but anyways, a small resistance e to ground, not as big as usually suggested makes a difference. like i think i said originally, this is for q's with an hfE of around 215... so 220r and 47 r work real well. if i was using 3904s which seem to float around 360-400, i'd go 470r and 100r. 5088 or whatever, 1k, 220 r or 330r... it seems that as you increase the e resistor, it decreases the gain at a rather predictable amount. but then you kinda HAVE to mess with the c resistors to get it to react right. it's almost like the e resistor affects how much balls, and the c resistor affects the sensitivity of it.

but yeah, anyways, back to point, yeah, 5.6k is valid, 10k, whatever makes it sound the way you like. with the particular q's i used, and because they were so consistent in the bag, i found 8.2k worked perfect and consistently as the stock value so i went with that. something about the added resistance of the transistor... and i know i've read about this shit but can't quite remember (been kinda outta it since that stroke thang last year)... is what lets ya set the gain that's unuseable to a useful one. i wish i knew enough theory to understand it, it just works.

so my boards fit pretty much on a vero 8 rows down by 9 holes long. there's like, 15? 16? wires coming off it. fitting it in a 1590 is hard! ;)


so yeah, 5.6k is perfect probably for your transistors. i like having the extra pot sometimes too. i may add a starve control to one too... these do sound different a little on batery than power supply, but it's pretty close.

i did 6 hours in a local studio yesterday, playing country blues punk psychedelic shit for a local artist's live video shoot.
i turned it full blast. photon face side. used a suzy q overdrive (one of mine, look it up) and as predictable with me, noise reduction (ns2) a pt2399 style echo and one of them behringer digital reverb modelers, the deep blue ones, into my fender pro (late 70's, ultralinear 70 watter into 1 15" jbl d130 with a hammond long decay pan all stuffed in an old vibroverb box), had the volume and master on the amps about half up.

never turned the fuzz off once. played literally all kindsa bizzarre shit and got everything i needed, from uber over picked hyper rockabilly to gilmore style humongous. it feedsback right. for ME to be satisified with a fuckin silicon fuzz face.... lets just say, i am the high priest of the cult of germanium... and i am not wanting for anything at all with this design. the tone is there, most of the interaction is there, not too shrill, cleans up almost identically if a/b'd... man, i gotta make a video, but all i got in stock is the tiny one without the second footswitch. fuck it. the ol lady is out. i gotta couple hours. get some coffee grub and funny veggables in me and see if i can't make a stupid pedal trick up. a/b shit back and forth between the originalish germanium DA fuzzface reissue and this silicon thing.

the important thing and the only thing that matters is that if this works for you, i am happy.
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Post by pinkjimiphoton »

Manfred wrote:Hi brother Jimi,

thanks a lot for giving exhaustive informations.
. i just use it differently, cuz the board you layed out won't fit in a 1590a. but it's perfect just the way you have it brother.


How large does the board have to be?
it would have to be about 1 inch square, max, bro.

that way, if ya mount them 16mm alphas we all use on the sides of the enclosure near the jacks, you can usually just squeeze the board between them if you use 16v electros.. still an awfull lot of wiring to be done any way ya look at it.
or could use 9mm alphas, the pc mount ones. i've been snapping off the pc mount brackets and mounting them like normal pots. that gives a little more room in the enclosure, but it's still pretty tight.

i guess ideally, make it for the 9mm pc mount style pots, and mount 'em right to the board. there's just enough room to fit 'em in that way, and if the pots are facing up from the solder side of the board that gives somewhere for the population and wires to go. i'll try and scrounge up some pix, they should be on my facebook wall too.

thanks for the support, and glad you guys diggit. be back later with pics/video/both
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Post by pinkjimiphoton »

and hey, can someone smarter than me explain why the fuzz pot works and sounds different depending on whether the 22uf cap's cathode is connected directly to ground, or coupled with the 100r resistor? does it make the cap seem bigger maybe due to ESR or something? or is it a low pass filter.. i mean a cap in series with a resistor to ground makes a filter, right? and a variable resistor into a cap makes a high pass? my widdle bwain is melting...
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Post by pinkjimiphoton »

pics.... will get video shortly. gonna a/b it with an actual germanium fuzzface.

Image

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Post by pinkjimiphoton »

stupid pedal trick as promised

stupid pedal trick for the schizoid face, a/b-ing it with a germanium DA dunlop reissue fuzz face so ya can hear the differences and similarities. does it sound identical? nope. but this is the closest i've ever found. check it out.

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Post by Manfred »

Hi Jimi,
i just use it differently, cuz the board you layed out won't fit in a 1590a. but it's perfect just the way you have it brother.
I have a lot of hard work ahead to fit all components on a 1 inch by 1 inch PCB.
In some cases components can be ommitted on the PCB and placed outside of the board.
I refer to C1A, C1b, C3 and R7.
There is, however, one problem, it takes time because my in-patient rehabilitation measure starts in two weeks for a period of about six weeks.

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Post by pinkjimiphoton »

sorry bro ;)

take a look at the vero layout maybe? it may take a couple jumpers.
the pulldown resistors can be off board, the fuzz electro could be mounted on the fuzz pot itself,
could use them little monolithic deals for the onboard caps, tantalum for the electros. all the power supply stuff can be put on a little piece of vero or
as daughterboard.
use 9mm board mount pots maybe, fit the whole circuit on a board the size of a postage stamp.
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Post by Ripdivot »

pinkjimiphoton wrote:and hey, can someone smarter than me explain why the fuzz pot works and sounds different depending on whether the 22uf cap's cathode is connected directly to ground, or coupled with the 100r resistor? does it make the cap seem bigger maybe due to ESR or something? or is it a low pass filter.. i mean a cap in series with a resistor to ground makes a filter, right? and a variable resistor into a cap makes a high pass? my widdle bwain is melting...
The 22uf is called an emitter bypass cap. For AC signal it bypasses the other resistance in parallel with it to maximize the transistors AC gain. When it is connected to the 100 ohm resistor, that resistor is in series with the cap so it is limiting the AC signal gain. When connected to ground it is bypassing the 100 ohm so the gain is maxed out. Think of the 22uf cap as a zero ohm resistor for AC signal gain. Clear as mud?

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Post by pinkjimiphoton »

thanks for the explanation.

so it's essentially a gain limiter in this particular useage. makes a lot of sense, i'm just not all that savvy on electrical anything ;)
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Post by triplesevener »

Ripdivot wrote:
pinkjimiphoton wrote:and hey, can someone smarter than me explain why the fuzz pot works and sounds different depending on whether the 22uf cap's cathode is connected directly to ground, or coupled with the 100r resistor? does it make the cap seem bigger maybe due to ESR or something? or is it a low pass filter.. i mean a cap in series with a resistor to ground makes a filter, right? and a variable resistor into a cap makes a high pass? my widdle bwain is melting...
The 22uf is called an emitter bypass cap. For AC signal it bypasses the other resistance in parallel with it to maximize the transistors AC gain. When it is connected to the 100 ohm resistor, that resistor is in series with the cap so it is limiting the AC signal gain. When connected to ground it is bypassing the 100 ohm so the gain is maxed out. Think of the 22uf cap as a zero ohm resistor for AC signal gain. Clear as mud?
Not just that, but changing the value of that cap can adjust how much low end gets boosted. 22uF ensures that pretty much anything gets through. It's just like the Marshall bright channel, which uses low-value cathode bypass caps to chop off some low end.

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Post by pinkjimiphoton »

hahahah i think i alienated the other forum again ;) ooopsies....


so like... gotta question.

ya know how a good fuzz will clean up nice as ya turn down?

and start to act like a bit of a treble boost? right. that part.

if you wanted the tone to stay more consistent as you turn your guitar down,
could you do the opposite of a "treble bleed" and make a low pass filter by using the resistance of the guitar being turned down to shunt more treble to ground?

i'm thinking a simple cap to ground before the input of the circuit... i'd expect i'll have to play with values some to get it where i'm happy, but maybe somewhere between 10n and 100n ought to do it maybe? i'm thinking right before or after the input cap. before it actually seems like the only way it wouldn't be isolated from the guitar by the input cap itself. that should produce a treble roll off as the pot is turned down, right? or am i missing something <<<<<what i expect, that...
is there a better way?

i love the fuzztones. like nothing else. but i would like to find a way to combat this aspect of them. be nice to have my les paul not sound like a tele when it's barely on.

thoughts and edumakashun gratefully accepted

i don't want to kill any high frequencies when the guitar is pegged... can use the tone knobs for that. only as the guitar is turned down.

FWIW, i leave my fuzz face generally wide open into an overdrive (suzy q) and control the whole mess from my guitar. that's the basis of my guitar sound generally. (and it's not a fuzz bomb fest like ya may expect ;) )
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Post by Manfred »

Hi bro Jimi

I could took the notebook with me to the rehabilitation hospital, so I created the small Layouts earlier as promissed. (1" x 1")

I omitted the power supply part and made an extra PSU board ( 1" x 0.4")
R9 4.7 MegOhms is omitted too.
SchizoidFaceSmallLayoutMain.JPG
SchizoidFaceSmallLayoutMain.JPG (58.43 KiB) Viewed 3146 times
SchizoidFaceSmallLayoutPSUMain.JPG
SchizoidFaceSmallLayoutPSUMain.JPG (22.69 KiB) Viewed 3146 times
SchizoidFaceSmallLayoutMain.pdf
(89.93 KiB) Downloaded 104 times
SchizoidFaceSmallLayoutMainMirrored.pdf
(89.77 KiB) Downloaded 112 times
SchizoidFaceSmallLayoutPSU.pdf
(88.69 KiB) Downloaded 96 times
SchizoidFaceSmallLayoutPSUmirrored.pdf
(88.68 KiB) Downloaded 89 times

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