hey my friends,
i just wanted to hip you to a quick revision on the juergulator. i finally have a couple days off to mess with the circuit some.
i think i've improved on it... all the same sounds are in it, but it gets a bit more now.
here's the deets... swap out the 50k harmonics pot for a 10k... now the harmonics pot will be more useful, instead of all bunched up near the top, and you'll gain a little more balls. also, it lowers the input impedance significantly and makes the juerg way more friendly to guitar knob tweaking, like a fuzzface.
next up, take the "tweak" (or as i call it now, the "focus") pot and bump it up from 500k to 1 meg. you can go to TWO megs if you want to probably. this will make it much more obvious... almost like a tone or attack control... still subtle, but definitely more noticeable.
you can also try raising the percolate value to 250 or 500k most likely, tho i haven't tried yet.
this one i just finished is built to miro's excellent layout on tagboardeffects.
miro, i can't thank you enough.. really really groovy layout!!
i guess this makes it juergulator rev. 1 if you make the changes.
all pots linear
again, pnp ge russian mn25b, this one's hfe is 62
and a bc547, this time an hfe of 580.
i think we can call it done.
rock on, my brothers and sisters of diy
talk soon
peace
pink jimi photon
ReplyDelete
all the layout , schem demos etc are here.
i had someone trade me a mid 70's epiphone crestwood for the one in the video, this stupid little dano hodad does not do justice to the sound of it.
if you like percs, try this thing out. i think you'll be surprised.
;)
http://www.diystompboxes.com/smfforum/index.php?topic=102861.msg932469#msg932469
miro's layout
http://tagboardeffects.blogspot.com/2013/09/pink-jimi-photons-photonic-juergulator.html
Dude, you are awesome 8)
(http://i605.photobucket.com/albums/tt137/pinkjimiphoton/942182_10201403180394366_691940397__zps8f708987.jpg)
all i can say is wait'll you hear this $#i7.
seriously. it's surprising the hell out of me. just boxed the first "official" one, gonna put it to trial by fire at enforced recreation, live on stage tonite.
:icon_mrgreen:
you can dial in the harmonics/octave with the percolate control, and adjust the contour and slipperyness with the focus control.
the focus adds more high end harmonics as you turn it up.
video to come soon. ;)
If it sounds better than the original, it must be incredible.
The Guitar FX vero adds a 10K resistor from the Harm pot pin1 to ground and you're changing the pot to 10K, so is that 10K resistor a bad idea now?
Also, you have a 47R and a 100K in series from power in - probably don't need the 47R right?
Quote from: GGBB on September 18, 2013, 05:13:33 PM
If it sounds better than the original, it must be incredible.
The Guitar FX vero adds a 10K resistor from the Harm pot pin1 to ground and you're changing the pot to 10K, so is that 10K resistor a bad idea now?
nope, it's good... that just makes it so you can't turn the volume all the way down... or you could omit it. i don't think it would matter much. gives it a load of 20k i guess like that. i'd imagine tho you could omit it completely.
Quote
Also, you have a 47R and a 100K in series from power in - probably don't need the 47R right?
yah, i guess you could leave it out. it's really only there to help quiet the power supply a little. pretty negligible effect i'd imagine. when originally done, this had the 47r resistor in series with the b+ to help smooth the ripple a little, then it had a reverse biased 1n4001 to ground in parallel with a 100u cap, a 560p cap, and then another 1n4001 in series for overvoltage/reverse polarity protection. you can add it or subtract at will. i generally add that stuff anyways if i'm gonna be running off a wart. that one stupid little resistor can make a huge diff in noise sometimes.
remember, i'm a hack. i take the 10,000 monkeys approach, i'm sure there's stuff that could be improved on this. i mean, i found some huge improvements on it just this morning. so if it doesn't seem necessary, it probably isn't. 47r is pretty negligible and i don't think it adds any mojo whatsoever.
fwiw, the 47u cap is an electro, the rest are chicklets or ceramic. no real difference in tone that i've noticed, maybe just a touch more upper harmonic ring with ceramic. all the resistors are 1/4 watt carbon comp. i think the 470k was a metal film. that's it, no mojo really.
for authentic jimi photon vibe, use an ultraclear blue led with a 10k clr on the + side, and another 10k between switch and ground. no pops, no led noise that way.
seriously thinking about adding the transmission control from my transmission overdrive to this thing to play with the octaves more. i bet it would sound hip to be able to pan between the ge clipper and maybe some led's or bat41's.
[/quote]
Thanks Jimi. This is on my list for sure. I have redrawn the schematic and am almost done with a PCB layout - will post them soon.
thank YOU gord!!! ;)
took it out last nite put it thru it's paces...
the other guitarist took it home to try... he's bringing it back tonite
one of the bass players WANTS IT...
i think you'll diggit!!
Here are the goods. I added a power protection/filtering section and a status LED - if there's anybody who doesn't want it then just leave it out or jumper it where necessary. Pots are board mounted. Extra grounds and two LED connections depending on how you orient the board and where you want your LED. Board size is 2.2"x1.7" so it will fit in a 1590B.
EDIT: You can flip the board vertically and mount the pots component side with the solder side facing down if you like - that's the way I intend to do it.
Schematic:
(http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=49690)
Layout:
(http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=49694)
PCB Transfer (300DPI):
(http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=49697)
NONE of this is verified - use at your own risk - please post problems here and I will correct them.
looks awesome gord!! ;)
Nice! It's on the list! Thanks!
Brilliant job GGBB.
Just a question: Do you really need both D3 and D4?
***
I played with it a bit during last weekend, and got me a pcb design as well. Doublesided and unverified yet. If its ok (Jimi?) and you like me to, I gladly share it here. Might not be necessary though, with Gords great job done:)
I am still lookin forward very much to build this up!
Cheers
hi bengt, yah, you need the diodes...they're what makes the octaves happen, take 'em out and it's a jerkulator.
i didn't experiment with using silicon, so no idea if more ubiquitous diodes will work well or not, tho i imagine it may be a wee bit louder without them.
i would love to see your layout, too, so please feel free to post away bro!! it's an honor to be able to give something to the community and have the community give something back.
i hope to day in between doc appointments and crap i can video the juerg so you guys can hear it.
did you build this as posted, bengt, or did you try the updates?
Quote from: Vallhagen on September 20, 2013, 04:12:14 AM
Just a question: Do you really need both D3 and D4?
No - that's the power protection stuff I added. D3 protects from reverse polarity and D4 protects from over voltage - and I just realized I typoed on that one - should be 1N4739. I would normally leave out D4 myself, but for those who want extra security I added a place for D4. You can jumper D3 as well if you don't care about that stuff at all.
whoa, my bad, sorry!!
yah, i usually just use 1n4001's there, 4739 is a better choice. i didn't add them or anything like that on this build, i've found with percs sometimes they don't seem to run right with too much filtering on the power. it's such a weird ass circuit.. ;)
As Jimi said you can also use 1N4001/2/3/... - at D3 for series reverse protection, or jumper D3 and put one at D4 for parallel reverse protection.
Quote from: pinkjimiphoton on September 20, 2013, 07:29:45 AM
i would love to see your layout, too, so please feel free to post away bro!! it's an honor to be able to give something to the community and have the community give something back.
Awrite, here we go:)
As said, this is NOT verified yet. Basically its like your original post Jimi, a small 100p cap added, and I also skipped the two resistors around the Tweak pot.
And as you see, I go with my routine, and use an 1N4001 for pwr polarity protection.
Complete EAGLE project, packed file:
https://dl.dropboxusercontent.com/u/10190945/juergulator/juergulator_Vallhagen_1.rar (https://dl.dropboxusercontent.com/u/10190945/juergulator/juergulator_Vallhagen_1.rar)
High resolution Schematic:
https://dl.dropboxusercontent.com/u/10190945/juergulator/juergulatorSCH300_1.png (https://dl.dropboxusercontent.com/u/10190945/juergulator/juergulatorSCH300_1.png)
Lower resolution schematic:
(https://dl.dropboxusercontent.com/u/10190945/juergulator/juergulatorSCH150_1.png)
Board Layout (this is, if wanted, easily tweakable to a onesided layout):
(https://dl.dropboxusercontent.com/u/10190945/juergulator/juergulatorBRD300_1.png)
Cheers!
Quote from: GGBB on September 20, 2013, 07:49:52 AM
Quote from: Vallhagen on September 20, 2013, 04:12:14 AM
Just a question: Do you really need both D3 and D4?
No - that's the power protection stuff I added. D3 protects from reverse polarity and D4 protects from over voltage - and I just realized I typoed on that one - should be 1N4739. I would normally leave out D4 myself, but for those who want extra security I added a place for D4. You can jumper D3 as well if you don't care about that stuff at all.
Thanx for clearing that out:)
Quote from: Vallhagen on September 20, 2013, 10:30:22 AM
Quote from: pinkjimiphoton on September 20, 2013, 07:29:45 AM
i would love to see your layout, too, so please feel free to post away bro!! it's an honor to be able to give something to the community and have the community give something back.
Awrite, here we go:)
As said, this is NOT verified yet. Basically its like your original post Jimi, a small 100p cap added, and I also skipped the two resistors around the Tweak pot.
And as you see, I go with my routine, and use an 1N4001 for pwr polarity protection.
Complete EAGLE project, packed file:
https://dl.dropboxusercontent.com/u/10190945/juergulator/juergulator_Vallhagen_1.rar (https://dl.dropboxusercontent.com/u/10190945/juergulator/juergulator_Vallhagen_1.rar)
High resolution Schematic:
https://dl.dropboxusercontent.com/u/10190945/juergulator/juergulatorSCH300_1.png (https://dl.dropboxusercontent.com/u/10190945/juergulator/juergulatorSCH300_1.png)
Lower resolution schematic:
(https://dl.dropboxusercontent.com/u/10190945/juergulator/juergulatorSCH150_1.png)
Board Layout (this is, if wanted, easily tweakable to a onesided layout):
(https://dl.dropboxusercontent.com/u/10190945/juergulator/juergulatorBRD300_1.png)
Cheers!
bengt, you REALLY need the two resistors around the tweak pot. the tweak pot doesn't make a lot of difference without them. seriously. nite and day, bro... you wanna add them back in. definitely. and use the revision values. 1 meg for the tweak pot is a HUGE diff, without them resistors tho, the tweak pot doesn't really do sh*t.
looks great tho!! ;)
EDIT: you need the two resistors, or go to a 2meg pot. the resistors also are important for setting the range of the second gain stage, and prevent you from getting too high or low... too high, and it becomes unstable, too low, and it could become unuseable.
the harmonic pot in this needs to be 10k, not 100
the tweak/focus pot needs to be 1m for best results. i tried a shit load of different value pots, and these two changes are literally HUGE tonally.
i mean, you can build it however you choose, but you won't get the same sound out of it as shown. i started with the 1 meg with no resistors... it's not even the same animal without them on the focus control. try it on the breadboard, i believe you'll find them worthy of inclusion.
the harmonic pot at 10k lets the guitar and fuzz interact way better than any perc/jerk i've tried. huge difference, and the harmonics pot actually works over most of it's range instead of being all bunched up in the last 1/8th turn.
not trying to be a bitch.... just want you guys to try it as envisioned before ya leave stuff out thinking it's unimportant.
by all means, if ya don't like it do what ya choose... but it won't sound the same, that i can 100% guarantee.
also, you may wanna re-visit the pots with the wipers tied to pin 3. i did do that, and it sounded and worked far better as a simple 2 connection variable resistor (particularly on the focus control)
this thing keeps surprising the hell out of me.
i thought it could use a little more volume. i found q2 doesn't matter much.
but q1 sure seems to. and against what i thought would be logical, it is louder/gainier/more distorted the LOWER the hfe of the transistor..
i tried a whole bunch of 'em, the one i stuck with has a gain of maybe 40. much better.
q2 i ended up putting on a switch, one side is the stock with the bc547, the other side an AC176.
MAN... i'm sold. the two are very similar, yet worlds apart.. as expected, the ac is fuzzier sounding, and the bc a bit more strident.
the octave response is different, as is the response of the focus control. with the si, it's almost like a tone control in a way...but with the ge, it's like...
kinda.... controls the sustain, bloom and character of the fuzz.
tomorrow when gineen goes out, i'll shoot some video. i think you guys will approve.
peace
Quote from: pinkjimiphoton on September 20, 2013, 06:53:21 PM
not trying to be a bitch.... just want you guys to try it as envisioned before ya leave stuff out thinking it's unimportant.
Thanx for comments. And no, I don't think you're tryin to be a bitch ;D ... rather the opposite.
But just to explain how I thought in the first place: As your first (the one in the competition) version had 47k fixed + 470k fixed + 500k pot between Q2-s C and E it gives you an adjustable range between roughly 500k and 1M. Replacing them with just a 1M pot gives you and adjustable range 0-1M, which should cover it all. And I could argue for that if it is mounted as a trimmer, even if the trimmer range is unusable for the first halfturn.
Now on the other hand, as you move up to ver 1.0, 47k fixed + 470k fixed + 1M pot gives roughly an adjustable range from 0.5M to 1.5M. And that's a difference. Also, I notice that you skipped the trimmer in favor of an enclosure-pot.
So hey... I will come up with a new revised pcb design.
Cheerio!
Jimi
I believe I posted the following before. Something else to try a two NPN version
(http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=23006&g2_serialNumber=2)
(http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=43462&g2_serialNumber=2)
Quote from: Vallhagen on September 21, 2013, 01:56:56 AM
Quote from: pinkjimiphoton on September 20, 2013, 06:53:21 PM
not trying to be a bitch.... just want you guys to try it as envisioned before ya leave stuff out thinking it's unimportant.
Thanx for comments. And no, I don't think you're tryin to be a bitch ;D ... rather the opposite.
But just to explain how I thought in the first place: As your first (the one in the competition) version had 47k fixed + 470k fixed + 500k pot between Q2-s C and E it gives you an adjustable range between roughly 500k and 1M. Replacing them with just a 1M pot gives you and adjustable range 0-1M, which should cover it all. And I could argue for that if it is mounted as a trimmer, even if the trimmer range is unusable for the first halfturn.
Now on the other hand, as you move up to ver 1.0, 47k fixed + 470k fixed + 1M pot gives roughly an adjustable range from 0.5M to 1.5M. And that's a difference. Also, I notice that you skipped the trimmer in favor of an enclosure-pot.
So hey... I will come up with a new revised pcb design.
Cheerio!
hi bengt,
yah, the original idea was to be able to just vary the pot a little bit, so 500k was good... but being able to take it up to 1.5m is twice the gain of the original circuit. it's subtle still, but really different and useable. i don't wire the unused pot terminal to the wiper, i figure the fixed resistors will be good enough, as you say, you can only adjust the pot half way if you do that, but as a variable resistor, it gives the full pot range.
so... you can go from 470k to 1.5m roughly. that's a good good thing!!!
going down on the input "harmonics" pot also makes a huge difference, too...
i just shot video, it's rendering... as soon as it's done, you guys will see why i'm raving about this!! ;)
that looks cool, gus, have you built one yet? how does it sound?
will two npn's work and still do the same effect?
i like how you went with some simpler, more normal values... i like that a lot.
The bottom one is built and it sounds good. It has the nice feedback.
I measured the hfes of the 2n2222s with the HF meter.
I am guessing a number of people use that type meter to measure hfe.
I have also built one with a 2n2907 and 2n2222 with different resistor values
I used a 100uf Al electrolytic to be closer to a 47uf tant ESR
Hunting ebay for some 1N60's to give this project a shot, found a seller in Michigan, next door to me in Ontario, 2 diodes- 99¢ US, shipping to Canada- $23.99US... i'm going to keep looking.
http://www.ebay.com/itm/2X-1N60-Germanium-Diode-for-TV-FM-AM-Radio-Detection-/170852090875?pt=US_TV_Boards_Parts_Components&hash=item27c79403fb
dave, screw ebay!! get 'em on tayda for like a nickel a piece!!
gus... sounds good, i will give it a try one of these days!!
ok.... that said.... excuse the wanky wanky....
i present the stupidest pedal trick of all,
the photonic juergulator mk 1.5
Sounds cool Jimi!
Tayda lists their 1N60's as Schottky's not germaniums so are you using the schottky's or have some germaniums? I can get some NOS germaniums out of Toronto, nearby would be here fast. I see slews of 1N60P Schottky's coming out of the far east. Also a source in Turkey for germaniums at a comparatively reasonable price, but takes acouple weeks.
http://www.muzique.com/news/fake-ge-diodes/
Take care
dave
cool, thanks dave....
in this one i'm using the glass ones with a black band on one side, which i guess is different from the 34, which has either 2 black ones or a green one.
them are shotkys? no foolin'.... i can't tell the diff tonally, i've been using them pretty much all the time lately instead of buying the glass ones...
i always seem to break half of 'em bending the leads, so i got frustrated.
but yah, i guess use the ge. the shotky's would probably work too, but may sound different.
Yeah....
I've been through this one already.
Schottky 1N60
http://www.alldatasheet.com/datasheet-pdf/pdf/122948/FORMOSA/1N60.html
Germanium 1N60
http://www.taitroncomponents.com/catalog/Datasheet/1N60.pdf
Go figure!
Didn't know about the two versions of 1n60 before, so thanx for info:)
**
Ive now had this JÜERRRRRGULATAHHH! thing up on my breadboard for a few hours, and I can verify its a fun thing:) ... It adds life. And gives a sound that a non-fuzz dude as me founds very pleasant on lead tones. Ive only played it bedroom-quiet, and I really long for boxing it up and try it out screamin feedbackin loud.
I had one Russian pnp with Hfe=62 in my drawer, perfect fo Q1. I picked a MPSA18 for Q2. I also tried an AC127 for Q2, but that didn't really sound good at all. I guess it need tweaking cuz of the big difference in Hfe between the ge and si one, so I stick with SI.
I don't have (any version of) 1N160 here either, so I picked another ge diod from my drawer: AA112.
Cheerio
fwiw, the shotky and ge sound real close to the same!!!
i am psyched you diggit, bengt, that makes me feel real good... today i kinda NEED that.
if you can go a bit lower on hfe for q1, you may like it even better... i'm sure an mpsa18 is a great choice for q2~
the ge for q2 needs to have pretty high gain if you go that route, i got one reading about 260 in there in the video demo and it's a little louder than the bc547.
this thing sounds even better into a distorted amp, or with a fuzz pushing it.
rock on!! :icon_mrgreen:
Just got around to checking out the SPT video, Jimi. Looks like I have yet another addition for my "to do" list!
BTW, I particularly enjoyed the "stupid glasses trick" at the beginning. I'm always doing that... :D
Hey Jimi, is the layout of this at Tagboard the same as the version you're demoing just a few posts above this? Really, really liking how this sounds. Seems like you've unlocked some of the mysteries of what this circuit is capable of! :)
read my notes in this thread or at tagboard. what you hear in the last video is the layout done by +mirosol from tagboard.
after he made it i changed the harmonics pot to 10k, and the tweak pot's name to focus and it's value to 1meg instead of 500k.
mine has a switchable q2, a bc547 with a gain of about 360 on one side of the switch, and an ac176 on the other with a gain of about 230 or so @about 6ma leakage. it balances nicely with the bc547 volume and tonally.
but yes, the tagboard effects layout is what you're listening to.
the two knobs are both subtle and radical at the same time. it's very weird how they interact. you almost can't tell they're doing something sometimes until you start playing thru it and it reacts totally differently...
and of course, to me the best part is that it cleans up like a fuzzface now... all them sparkly even order harmonics stay even when it's clean and crystally.
hope ya diggit when ya build it bro. peace.
That makes perfect sense--thanks Jimi! I'll just make these notes when I print Miro's layout and I'll be good to go. I really appreciate that this uses such easy-to-source parts.
all good. i wanted something you could almost build with radio shack parts if ya had to.
the "mojo" is all in the setting... i bet the guy who invented it did it while looking at an o-scope like in this:
i downloaded an oscope so i can see what the juerg does, try and make a little more sense out of it.
I just saw this for the first time yesterday. It's interesting. We hooked my working build and my f'ed up one to a scope at work this past Friday. The curve was similar to what is seen in that clip on my working one, whereas my oscillating, theremin-sounding one looked like this jagged, saw-tooth wave.
What caught my eye was how the whole line would move higher or lower on the grid depending on which diodes (ge, si, or no diodes) were in the circuit. I'll be curious if you see similar movement with your Q2 switch!
Nice, Jimi! My build is underway ;D
Larry
thanks larry.
haven't forgot about ya, too goddang busy
Hey Jimi, in the midst of a crazy and stressful week at work I managed to find time to finish my build using Miro's layout. I think this is an awesome circuit! Thanks for putting this out there for the community. I hooked it up to my test box last night and had a blast.
So, I did used the 1n34 and 1n60 as you suggest. For Q1, I have an old General Electric 2n1305. It's not very leaky and measures at about 49 hfe using R.G.'s method. For Q2, I have a BC549c in there with 550 or so hfe. Do those sound like a good combination gain-wise? I've actually got 2n3565s but it sounds so good as is I may keep that setup intact.
Sonic impressions--at first blush, it sounds similar to the Keeley Fuzzhead I did recently (and I couldn't tell you how close that sounds to the original). Not totally unlike my Albini-specs Percolator, but less dark and compressed. But then I started playing with the percolate knob. This is where the magic happens! I cranked it, hit a power chord, and just let it ring out. It just sustained and bloomed into this ear-pleasing harmonic feedback. Just to clarify why that was so special, I was playing through a stock Blues Jr. with the pre and master volumes both at 4, and a Mustang with some fairly low output pickups! Never had a pedal that could do this at bedroom-ish volume.
I'll have to play with the focus knob more to figure out what works best with my setup. I like what it does but can't describe it. Is there a setting on that knob that would make the most sense with my setup?
All the best,
Bret
just sweep it til ya find the sweet spot bro, that has more of an effect on the "feel" and bloom than the tone. it's subtle, but it's there.
really psyched you liked it.
any transistors that sound good to YOU are the CORRECT ones. ;)
Thanks again--will mess around with it some more tonight. Forgot to mention--even without any power supply filtering, it's not particularly noisy. No more so than my other one, which was on the Madbean Pepper Spray board. That has a 100uf filter cap.
When I box this, I may just put it in a sparkly pink box and call it the "Photonic Pinkulator"! I mean, I wouldn't really label it or anything (not a big decal fan), just a fun nickname in your honor. ;)
swirl paint a psychedelic box, pink, magenta and lime green.... ;)
i would add a simple power supply filter. i didn't show it on the vero or schem, but i usually use a 100-220u cap across the power jack pos and ground at the very least, but usually i do something like this:
(http://i605.photobucket.com/albums/tt137/pinkjimiphoton/PJPPSU9V_zps6bd35ef8.png)
depends on the pedal. some don't need psu filtering, some do, some don't seem to wanna work with it even.
but i usually use a scrap of vero and put the crap all on there, but you could solder it to the back of the power jack too if ya wanted to.
Thanks man, that is super easy. I may add this on when I box it.
You will laugh over this. I realized I had kind of rushed when I tested this and found, first off, that I had Q2 in backwards. I flipped it and it suddenly sounded way meaner. However, it had this kind of weird, mis-biased, sub-octave thing going. I took a good look at my work next to Miro's layout, and found the 10k resistor next to Q1 was only linking the bottom four rows, not the bottom five as it should be. Fixed that and all is good!
Now, I'm just trying to get my head wrapped around it all! This is one mean box. I've built both Albini and stock specs Percs as well, so this was educational. Those versions are both pretty smooth and compressed even with the different amounts of gain on tap. I think the Jerkulator lineage brings its own goods to the table. It's got this edgier, more octave- or synth-overtone-laden sound compared to those other two versions. It sounds borderline-bias-starved, but will sustain really long--it's just fat and nasty on single notes. Chords have this dying amp, almost atonal thing going. More sixties fuzz-like, if that makes any sense. I even listened to some clips of straight-up Jerkulator build just to see how it compares.
So, hats off to you! You brought together the best of these circuits. I goofed around with a DMM just to see what the voltages are like. Looks like the focus and percolate controls actually allow you to vary the Q1 and Q2 emitter voltages--is that right?
yep, they control the gain to both stages and let ya dial it in.
i'll let miro know about the mistake!!!
not surprised a reverse beta sounds better at q2...often pinouts don't match the data sheets!!
sounds to me like you got it perfect bro. ;)
Oh, it was my mistake, not Miro's, unfortunately! I didn't follow his layout correctly, so the fix on that 10k resistor was to get it in line with his mapping of the vero. Sorry I wasn't too clear there.
Yeah, it is really interesting how this thing works with the reverse betas--it's true of both positions. I mean, following the schem/layout gets the meanest sound, but flipping the transistors can help you dial it in to taste.
i routinely flip transistors. whichever way it sounds the best is how i leave it!!! lol
sometimes they just plain sound better.
Nice circuit, I want to say "thanks" to Pink Jimi. I've spent the last couple of days messing with various HP circuits and mods. The Juergulator sounds the best for my rig.
I'm Using a Ge PNP and a Ge NPN. Si NPN ain't bad at all (bc547), but the Ge seems to be a little bit sweeter. Any random Ge PNP in Q1 sounds good to me, slightly different textures/gain/tone...it's hard to pick one...
My only mod (at this point) is to omit the clippers at the output - they don't seem to do much for me besides compress the signal.
welcome to the forum!! glad ya like it.
the clipper at the end i don't think is necessary. ge diodes there give a bit more octaves tho. ;)
revisited this last nite was quite surprised how differently the controls seem to work depending on the type and gain of q1.
lower gain ge definitely won for the pnp. i tried by ear several (shoot, maybe 20) different transisters from ge to si and gains around 20 on q1 gave better fuzz than a 3906 did definitely. tried ac128, a bunch of russians mn or mp or whatever the cyrillic is on it, and a bunch of others. on mine, q2 is hardwired to a switch to switch between si or ge.
but there's some little teeny tall tophat looking thing i can't make the numbers out on, i'd ordered a bag of 50 to try 'em and thought they were bunk. but in this they sound great... the gain on my meter (most stuff is packed up) was coming up at hfe of 18. little bastidge SCREAMS.
putting in a much higher (leakier) gain ac128 that was reading around 300 and it became almost more like a clean compressory boost with a hint of grit to it. very similar to the 3906. 5089 was even "cleaner"... the lower gain also seems to be louder...
my theory on that is that by not putting out as much, it's not hitting the second transistor as hard, so rather than driving it into clipping as it would with a high gain stage before it it's able to amplify more, with clipping on the peaks instead of the severe compression you get when driving the base of q2 to clipping non stop. try it and see.
the funny thing is that i built a jerkulator, same values specified by tim escobedo, and it sounded great. i gave it to house of lord's guitarist jimi bell, who's a local guy and an awesome musician as well as a beautiful cat. anyways... the escobedo circuit sounds more like the ge circuit, with a 3904/6 combo...
surprisingly similar. i don't know if the control change i tried to implement is making this happen, as otherwise the circuit is nearly identical, a dumbed down dumbed down version with a couple extra "range" knobs instead of fixed resistances. i would think the fuzz would be different with the same transistors.
maybe it was the gain?
anyways... onwards n upwards, good peeps....
Hey guys, I am planning to build one of these. I'm still a bit of a newb though, so I have a question:
I want to integrate the Perc and Focus knobs, but I already have a pcb using the Madbean Pepper Spray layout so I'm trying to figure out where they should go.
Jimi Photon -can you help a brother out?
PS. This all started with the Catalinbread Karma Suture for me. I've been eyeing a HP clone for years but that Cbread pushed me over the edge. I like the idea of more knobs for better fine tuning.
i'd have to see the schematic of bean's pedal bro. i dunno what he did. i have so many schematics it makes my ass hurt.
basically, this is a dumbed down version of a escobedo's harmonic jerkulator, which was itself a dumbed-down version of the interfax harmonic percolator.
if you look at the schematic in this thread, you'll see all i did was replace two resistors with two pots, one was a 1m resistor as i recall, so i figured out whatever resistance i could tag on both sides of a 500k pot to get above and below the original values... that way the original setting is there as well as above and below it, and tho you may think you could just do it with a 1m pot, parts of the range would be useless, and parts the transistor would cut off even. by adding resistors you can "tune" what part of the pot's variable resistance is most useful... or as useful as such a compromise can be.
same with the other resistor. look at the schematics and compare them... you'll see what's what. if you get stuck, hollar back, and please DO post the schematic... if it's something easy enough to do, i'll help ya figure it out. but.. caveats apply.
madbeans pedal may have different circuitry from mine, and mine is extremely dependent on using the proper transistors to really get the sound...the extra knobs come with a price. read this thread.
if you use too-high gain in q1, it doesn't work as well in the juergulator.... and i reccomend germanium here if possible.
look forward to seeing bean's take. ;)
peace, and welcome to the forum
Great quotes for signatures;
Quoteany transistors that sound good to YOU are the CORRECT ones.
and
Quotei routinely flip transistors. whichever way it sounds the best is how i leave it!!!
Like a black double brested suit, they are simply timeless classics. :icon_lol:
i've read about reverse biasing from jack orman and rg and many others, and sometimes, in a fuzz, you get better tone that way.
i don't know why reverse biasing has such effect, but it may be phasing, or it could be cuz of the way it changes the gain... take a fartier distortion with a lower gain, and squash it good into a loud stage and i believe it's definitely louder than slamming a signal into a second stage... the first way is more dynamic if ya bias i right, the second way will get you more unrelenting compressed 60's fuzzzzzzzzzzzzzzzzzzzzzzzzeeeeee goodness but it may not be what you're looking for.
i don't think it's gonna damage the transistors too much, and if it does, i lay out with... hey.... it's a distortion box, that hiss is vintage, dewwwwwwd...
;)
Jimi,
If you put a pot between emiters you can get octave up sounds out of it.
This is my version of the percolator that uses two germs,
(http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=41317&g2_serialNumber=1)
QuoteMy only mod (at this point) is to omit the clippers at the output - they don't seem to do much for me besides compress the signal.
+1
mac
that is a thing of beauty mac!!! well done!! i wanna try it with my circuit, a 5 knob percolator would probably be awesome!
i can get octaves with the juerg too, but they are octave down mostly... little octave up. so that mod would probably bring it even more to life! ;)
Quote from: mac on March 26, 2014, 01:51:32 PM
Jimi,
If you put a pot between emiters you can get octave up sounds out of it.
This is my version of the percolator that uses two germs,
Thanks for sharing the idea and schematic. Just when I thought I was done with all the Percolator breadboarding....
Quote from: machine.cuisine on March 26, 2014, 09:54:29 PM
Quote from: mac on March 26, 2014, 01:51:32 PM
Jimi,
If you put a pot between emiters you can get octave up sounds out of it.
This is my version of the percolator that uses two germs,
Thanks for sharing the idea and schematic. Just when I thought I was done with all the Percolator breadboarding....
Not much luck here getting octave ups, just throwing resistors in between the emitters. Maybe Mac's octave ups are a product of the double Ge and his particular/precise biasing? I am not done trying, but initial outlook is bleak.
Another note - I am going back to 100k on input, because this lets a fuller guitar frequency range in. However, I do like the somewhat "darker" harmonic feedback/tones with the 10k input - and, since this is DIY I am just gonna add a switch that drops a 10k across the 100k input pot.....will be called
PINK Mode.Actually, a lot of my testing has involved turning up my pedal-testing Peavey Pacer 100's volume and holding guitar up to induce feedback....I am listening for organic and wide-range feedback tones.
QuoteNot much luck here getting octave ups, just throwing resistors in between the emitters. Maybe Mac's octave ups are a product of the double Ge and his particular/precise biasing? I am not done trying, but initial outlook is bleak.
Yeap. Two germs needed, and due to the very nature of them you'll need to tweak values. Besides, it dates from 2007, a lot of weather changes since then ;D
IIRC, I put pots at both colllectors, from C to B and between emiters, until I sounded good.
Later I managed to get octave up using ge and si, or two si, but I can't find it in my notes...
mac
Hey Jimi, I had some fun revisiting this last night after reading about your Q1 experiments. I had a 2n1305 at about 50 hfe in there originally, then swapped it last night for a 2n281 (AC128-like) at about 35 hfe. Believe it or not, this made a difference and it now sounds better! If I can get ahold of an even lower-gain germanium will try it out as well. Before, it always seemed to have this hint of mis-biased sound going on. Now it finally sounds like the one in your epic Juergulator video clip. :)
if ya read uncle beavis's stellar runoffgroove site, check his article on the harmonic jerkulator.
he too found it sounded better with lower gain transistors, tho nowhere near as low as i've gone.... 18hfe sounds @#$%ing KILLLER... but it's really the balance between the transistors... that's what's nice about the juerg, you can kinda dial it in.
i've found with all the knobs up around half way, on the neck and middle of all my strats, i get these insane octave up/downs at the same time in certain ranges... the more i play with it...
but to me, it seems LOUDER with a LOWER GAIN transistor.
i think, and going out on a limb here, that by putting a smaller signal into a cranked stage, you get a bigger tone than you do by overdriving the base of the second stage. it can amplify much more linearly i think before it hits the rails and cracks.
if ya overdrive the base it's a much different sound... a lot more compression. it's more open, cleaner, and louder if ya don't... probably why some fuzzfaces are so much more dynamic than others.
Jimi et al:
Sorry if this is a dumb question - is it possible to use a silicon NPN flipped instead of a PNP for Q1?
I have no low gain PNPs either germanium or silicon. I know I should, as I am surely missing out on germanium fuzz awesomeness, but for now I don't (until the urge is no longer resistible).
Another possibly dumb question - does hfe matter independently of how you set the bias and gain (esp. AC) of the transistor? I *think* I know the answer to this is YES!, but I want to hear it from a fuzz expert.
My only fuzz is a high-gain silicon BC108C unit that I liked a lot at one time but it no longer sounds the way I remember building it and does not move me so I feel the need to fill the void - and I really loved the clips of this one.
gord... you can use a pnp si for q1, it may not react the same tho.
if ya wanna pm me your snail mail, i can send ya a couple of low gain ge's.
buy a bum a cup of coffee for me someday. ;)
the bias will affect the gain and vice versa i think... you should be able to compensate for either tho, this circuit is pretty forgiving. you may LIKE it with high hfe;
more octavey fuzz that way, for sure, and more compression.
Quote from: pinkjimiphoton on March 31, 2014, 05:20:13 PM
gord... you can use a pnp si for q1, it may not react the same tho.
if ya wanna pm me your snail mail, i can send ya a couple of low gain ge's.
buy a bum a cup of coffee for me someday. ;)
the bias will affect the gain and vice versa i think... you should be able to compensate for either tho, this circuit is pretty forgiving. you may LIKE it with high hfe;
more octavey fuzz that way, for sure, and more compression.
Thanks for the generous offer Jimi but I bit the bullet and have ordered a small assortment of Ge PNPs. It'll probably be a few weeks before they arrive.
Hey Jimi,
I get on a Percolator kick about once a year. I'm wondering--do you think tantalum vs. a regular electro would make a difference in sound for the 47uf that connects the two emitters via the positive leg? I know it makes some difference in the "stock" percolator circuit, good or bad I'm not sure.
Cheers,
Bret
hi bret,
i have no idea, really. i would suspect it may be a little tighter not being an electro, but i never tried it. i am still slowwwwwly getting stuff unpacked in my workshop, so it'll be a while before i can really get to tinkering again.
check it out if you have one, and please let us know your results!
rock on brother
peace
jimi
Hi Jim, i've been working on the pedal that you made,wanna ask ya whether which transistor is swapable with GE PNP HFE 52, cuz the country that i live in doesn't have that model.Thx
pretty much any ge pnp will work.
hell, they can both be npn, pnp, whatever. it should still work.
to my ear, sounds best with one ge and one si, but it doesn't really seem to matter which is which. socket and stuff transistors til it sounds good.
some transistors sound better reverse beta'd.
yes, HORRORS!! doing that is AGAINST THE RULES, but this is a FUZZBOX. rules need not apply too much when seeking inTENtional distortion.
so use whatever you can get in your country. odds are it will work. even silicon/silicon or ge/ge will work. i've built percolator/jerkulator/juergulators with all ge, all si, all npn and all pnp and they ALL work and sound pretty much the same... tho to me, the all ge sounds smoothest.
sorry if it seems like i'm dodging your question, but honestly, just install two sockets and have at it until you're happy. i tend to do that with every box i build. good luck,and thanks
for the interest in the juergulator. ya may wanna use the search function, as i updated this project a while back to the rev 2 standards, more gain, works with pretty much any transistors.
Interesting circuit!
I'd really like to know how this compares to the Catalinbread Karma Suture, which was released shortly after this thread started. Does anybody have a schematic fr the Catalinbread?
i haven't seen one, but would love to. it better not be the identical circuit, cuz then i may be an asshole. i believe i put no commercial use on everything i've ever done.