Here's a fun idea: an evolving circuit. I don't know how this'll turn out, but it's worth a shot
Basically, it's designed by the whole forum one piece at a time.
Rules:
1. You can only place, modify, or remove one component per page of this thread.
2. You have to modify the circuit based on the latest version. Even if it was posted 1 second before you ;)
3. You can't change something that was just added. You have to wait another turn before you can mess with it.
4. Someone has to build this at some point :P
Hopefully there'll be more than just 4 components!
Here's my contribution:
(http://i998.photobucket.com/albums/af105/phil2004/1.jpg)
P.S. Try and keep it small and legible. I'm using paint, saving as a monochrome BMP
Im actually unable to edit the pic but I'd choose the most common road and add a tranny in htere.. say... mmm 2n5088
could you add it please ?? :)
Vendetta's contribution and my own:
(http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=44919&g2_GALLERYSID=a51d22ac64e04610e065ea078982e11a)
SSRP time! (Or something else...)
I like where this is going! :)
470K resistor to vref (bias) from the tranny base
that's already some weird stuff, like the 2n5457 above the 2n5088 lol... could be used as a switch??? i have no clue where this will go ;D
(http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=44922&g2_GALLERYSID=a51d22ac64e04610e065ea078982e11a)
cool idea..... :icon_cool:
i'll have a 100k trim on the drain of the 2n5457...if someone could do that for me?.. :icon_wink:
edit: one per page!.....ok, i wont cheat!. :icon_mrgreen:
5088 470R resistor from emitter to ground
(http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=44925&g2_GALLERYSID=a51d22ac64e04610e065ea078982e11a)
nice one alex... ;)
its going to be interesting to see how, and what this develops into... :icon_cool:
50 uF capacitor on junction between Source of FET and Collector of Tranny and goodness knows what else!
Who's going to be first to say BSIAB?
BSIAB!!!!!
Do I get a prize? :D
(http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=44928&g2_GALLERYSID=a51d22ac64e04610e065ea078982e11a)
470 mH inductor next in series.
???
Never saw that one coming! ;D
Oh and kudos to Alex for updating the schematic
I'll try and get the next one lol
How's this? Or did you mean in series with the trimpot?
(http://i998.photobucket.com/albums/af105/phil2004/OPOCcircuit_004.jpg)
this thing so far goes really weird and cool at the same time!!
ahh hopefully i'll be able to breadboard one haha
From the 9V (where the trimer is) a cable to an IC (TL072) for a future LFO!!! :icon_evil:
1N4147, anode to JFET gate.
Quote from: richon on April 03, 2011, 04:14:24 PM
From the 9V (where the trimer is) a cable to an IC (TL072) for a future LFO!!! :icon_evil:
please enter somewere on the schematic, on my behalf, one resistor 47k ( I like its colors :D) as a starting point of Vref, needed for the above)
ill suggest the other 47k for v ref, so the 1st one won't be lonely... :icon_frown:
Richon, I like your idea!
Quote from: arma61 on April 03, 2011, 04:57:11 PM
Quote from: richon on April 03, 2011, 04:14:24 PM
From the 9V (where the trimer is) a cable to an IC (TL072) for a future LFO!!! :icon_evil:
please enter somewere on the schematic, on my behalf, one resistor 47k ( I like its colors :D) as a starting point of Vref, needed for the above)
Is this right?
(http://i998.photobucket.com/albums/af105/phil2004/OPOCcircuit_006.jpg)
Also, is the 1N4147 cathode supposed to go to the BJT's base?
EDIT: Added my page 2 contribution :icon_twisted:
He wanted the two 47ks to GENERATE Vref at the op-amp (needs to have no cap on it)
100kL wiper to diode.
With my contribution:
(http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=44940&g2_GALLERYSID=a51d22ac64e04610e065ea078982e11a)
Is that how you guys wanted the Vref?
I think the "47" values are very popular because the resistor band colours are complementary...
I don't know much about wahs, but it looks like you guys are making a filter of some sort... seems like this is going to be an auto-fuzz-wah :)
Great idea. The potential to desIgn the worlds best distortion is here. Don't know if it's a shame or brilliant whatever the circuit is is becoming something crazy!
Keep it up guys! I'll watch this one. Hopefully something cool to build or contribute to!
Here's an easy one. Please add a 22uF cap between the 47k's vref to ground for me for smoothIng...
(http://i998.photobucket.com/albums/af105/phil2004/OPOCcircuit_007.jpg)
Thanks, Darron!
I figure 1000 minds are better than one. Hopefully we'll all be able to learn something new from this.
Wow, this is interesting.
Quote from: phector2004 on April 03, 2011, 11:19:18 PM
[IMG]
I figure 1000 minds are better than one. Hopefully we'll all be able to learn something new from this.
Yeah, but 1000 minds on totally different tracks? :icon_lol:
And a transformer... Ohh, I'll wait till the next page...
2N7000 drain to tl072 pin 1, gate and source to vref
Quote from: JKowalski on April 04, 2011, 12:55:59 AM
Wow, this is interesting.
Quote from: phector2004 on April 03, 2011, 11:19:18 PM
[IMG]
I figure 1000 minds are better than one. Hopefully we'll all be able to learn something new from this.
Yeah, but 1000 minds on totally different tracks? :icon_lol:
I'm actually REALLY hoping it works whenever it's done... if ever ;D
I don't think I should start a new thread....
but I think we should start, on a long term base ;), also to think about a name for it... or you guys think it's too early ?? :D
This is already starting to look like it could become a really cool frequency-dependant tremolo, if the TL072 becomes an LFO and ends up connected t the 100K pot.
let's add a reverse polarity protection so the first step, 1n4001 with the banded side to the positive and the other side negative :D
How's this looking? Hope someone ends up doing something with the 1044! +/- 9V, maybe? Voltage doubler? Tripler? :icon_twisted:
(http://i998.photobucket.com/albums/af105/phil2004/OPOCcircuit_008.jpg)
Armando, what do you mean exactly? More focused designs?
No I mean the name for when, if ever, it will be completed ;D
and I would like to suggest... if this will ever become something real (may be with some corrections) we all do it in the same box with the same design layout knobs etc.. and the "diystompboxes.com" logo too!! :D
Sounds like a plan, but only if a certain forum member (http://www.diystompboxes.com/smfforum/index.php?action=profile;u=16691) etches the enclosures... So they come out all nice and uniform :icon_lol:
I don't know what the end-point will be, maybe when someone gets it working with tweaks? We can argue over the name then.
I agree with the logo idea. I wouldn't mind a DIY/tranny logo on it ;)
as for the name, we better see what's the final effect we are getting
cool idea but already f****d i think
Lots of ss actives, very little passives to round up
Not really... just a BJT and a FET, and an IC for an LFO probably...
The mosfet is being used as a clipper
Quote from: phector2004 on April 04, 2011, 03:00:16 PM
Not really... just a BJT and a FET, and an IC for an LFO probably...
The mosfet is being used as a clipper
yeah ok, but where is that FET going for?
And mosfet is being used as nothing at the moment.
I would've liked a diode-wired 2N7000 from collector to base. (body diode acts as clipper then) A mosfet bias. :icon_mrgreen: But the bias is there already.
seems like some discussion of what is needed, to make this thing into whatever it is to become, should be carefully considered...
like resolving the components that are floating without 'doing' anything yet...
like that 100k pot off of the diode from the jfet gate... what can we do there...
shall we feed that inductor/cap junction to a gain stage, what is a good topology there to take advanage of that indunctor...
i know, its a sort of 'tame' perspective, as opposed to just letting this thing explde with possibilities, but it seems so far that generally we've kept this thing from being absurd with some restraint and sence. the bigger it gets the harder it will be to do so.
so i'd just like to reccomend to those with some ideas ,to tie up the little loose ends before diving into a big adding frenzy?
i'm surprized that this thing is as sensible as it is with so many different people contributing... ;)
then again, i dont want to stifle any creative juices. rather i'd hate to see this thing become a mess, as its on its way to being an interesting device.
I agree... Aside from the "standard" components (reverse polarity diode, power cap), a lot of the other stuff doesn't have a specific purpose. I have no clue why the MOSFET was added, nor the inductor. Anyone wanna cue me in to what they're after?
Richon's got the right idea: state what you're getting at with your component additions.
E.g. I added the MAX1044 to run JFET gain stages at 18V, but it can also give +/- 9V for the opamp.
Is the BJT/FET pair supposed to be a SRPP? I think R.G.'s site has suggestions for that kind of stuff.
I agreed all the way. i just took a look at it again and, really, that diode with a pot or the inducter or mosfet...
anybody explain please?? :)
30.000volt AC psu... :icon_mrgreen: :icon_wink:
seriously though, an inductor has already halted my possibility of breading this ....and the mosfet!......and....
OK, so, my hunch is that the inductor serves two purposes: 1. They look cool. 2. Squiggly lines are fun to draw.
Now, I think I have figured out the third. I think that the inventor(s) of this circuit have read R.G.'s Dirty Tricks (http://www.geofex.com/Article_Folders/dirtytrk.htm).
I am absolutely convinced that the inductor is a ruse to trick potential cloners. ;)
(http://img43.imageshack.us/img43/7853/oneatatime.jpg)
Or not... whatever. ???
Mike
My bad, I missed the suggestion to steer the tl072 into an lfo. I threw in the mosfet for some ocd clipping, was gonna suggest the asymmetrical mosfet on my next page vote but do to strong protest, I'll accept the coalition's plea for removal. :icon_lol:
Technically, we can still use 1/2 of the TL072 as a gain stage or a buffer, but then we'd need another TL chip to keep the circuit from ticking.
Took the MOSFET off, as requested. No idea what's going on at the inductor part.
I also added a small todo list, to give this SOME structure
(http://i998.photobucket.com/albums/af105/phil2004/OPOCcircuit_010.jpg)
Oh and my contribution... are 1N4148's good for charge pump diodes? I usually use 1N5818s, but you're all more likely to have these in stock
EDIT: Ok, this is a bit of a "hand-still-on-the-chess-piece" move, but I'm switching to bipolar supply... 10uf electrolytic!
Hey, since there has been some desire expressed for the reasoning behind the suggested additions, I'll add mine.
The 1N4148 on the JFET gate is intended to constrain the JFET for switching duties only, not for amplification. When the JFET is on, the BJT is biased by the trimpot. When the JFET is off, the collector sees a very high impedance and it's not likely to be biased correctly.
What I envisioned was perhaps taking the output for the first transistor stage from the TOP of the JFET, rather than directly from the collector. This way when the JFET is off the output is essentially just the trimpot value to V+.
This could be used in conjunction with a second, identical setup of JFET+diode+trimpot to the collector, for multiple bias/preset levels.
Two different JFET switches gives you 4 possible presets for the BJT bias. (off/off, off/on, on/off, on/on)
You could switch these automatically with a 2-bit counter, and perhaps send each output to a different circuit for parallel processing.
The addition of the pot off the JFET spoils my plans but it could still be worked into something useful. For instance you could put a square wave LFO at one end of the pot and ground (or the negative rail if the charge pump ends up making this a bipolar supply) for a sort of "depth" control. It would be nonlinear but maybe that doesn't really matter.
???
Sounds like something interesting, but I'm completely lost...
If the JFET is off, wouldn't the output just be the bias DC? i.e. 0V after hitting a decoupling cap?
What would this be doing to the signal? What would it sound like?
I'm actually thinking of undoing my last addition, using 2 caps instead to get bipolar power...
Here's what I had in mind. Maybe it will help explain, maybe not... :)
(http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=44965&g2_serialNumber=1)
Say you make EQ1 a high pass filter and EQ 2 a low pass filter. By clocking the 4024, with a debounced pushbutton or a square wave, the mixer output will cycle through:
Q0 Q1 MixerOut
0 0 off (effect bypass maybe?)
1 0 low pass
0 1 high pass
1 1 notch or peak (depending on if the mixer is adding or subtracting the two signals)
But that's just one person's deranged ramblings.
holy mother jezus!!!!
;D
yeah, that sort of stuff definitely isn't possible laissez-faire component per component!
yeah but still that's a nice idea... tho i can see myself nt being able to breadboard this in the end... :(
Is that a non-latching SPST 4-mode splitter?
I've been looking for something that can do this for a while now :icon_biggrin:
No wait... tap-tempo EQ cycler?
QuoteOK, so, my hunch is that the inductor serves two purposes: 1. They look cool. 2. Squiggly lines are fun to draw.
Now, I think I have figured out the third. I think that the inventor(s) of this circuit have read R.G.'s Dirty Tricks.
I am absolutely convinced that the inductor is a ruse to trick potential cloners.
Haha. While I do admire an inductor symbol, I was wanting to do more than just that. C'mon guys, you can't think of anything that has a series inductor like this? I'm so disappointed... ;)
Wah?
You know, you can add another component to hint at what it's doing ;)
Any new ideas?
I like where earthstone went with it; we need an LFO, an inverting op-amp stage at the very least for that. (why go all the way when you can slide between?) You can draw those on as 'blocks', there's no point us assembling such standard subsets one component at a time.
How about number 2 here:
(http://i210.photobucket.com/albums/bb292/frequencycentral/VariousLFOs.jpg)
We can always adjust the DC bias and LFO amplitude later to go with the FET.
I think we need to do a bit of cleanup here. There are components here that probably aren't going to amount to much. So I think people need to use rule 1 to its full extent:
1. You can only place, modify, or remove one component per page of this thread.
In particular, I don't think the 1044 or inductor are going anywhere (unless ayayay! tells us what he's talking about :icon_confused:).
Quote from: earthtonesaudio on April 05, 2011, 02:00:19 PM
Here's what I had in mind. Maybe it will help explain, maybe not... :)
Say you make EQ1 a high pass filter and EQ 2 a low pass filter. By clocking the 4024, with a debounced pushbutton or a square wave, the mixer output will cycle through:
Q0 Q1 MixerOut
0 0 off (effect bypass maybe?)
1 0 low pass
0 1 high pass
1 1 notch or peak (depending on if the mixer is adding or subtracting the two signals)
But that's just one person's deranged ramblings.
That's wacky! Whether or not this thread ends up making it, I think you should look in to that.
Anyway, my contribution this time is removing the 1N4147 diode. We can still use the FET as the switch, but now we can use it in linear mode for a tremolo-ish thing.
I figured its easier making an oscillator with a bipolar power supply, but not everyone has charge pumps in their stash, and it's only saving about 2 or 3 components needed to run an opamp from 9V to ground.
I guess it's a good candidate for removal, then. The 1N4147 diode was a head-scratcher too... if anything, who not use a 1N4148 ???
I like the LFOs. Fig 2 looks simple, uses both opamps in the TL072
The diode is reasonable for what Alex wanted to do, and any of the normal silicon diodes would work fine. However, I wanted to open up options for people. So, the LFO could be used as a switch or it could be used to drive the FET for a tremolo. Alternatively, that allows us to use the stage as an SSRP by connecting the 100k pot to ground on one side, power on the other, and with a cap from the gate to the source. We also might be able to switch between the tremolo and SSRP.
i like it!
(http://i998.photobucket.com/albums/af105/phil2004/OPOCcircuit_011.jpg)
Here's the latest version
Can't update too much these next few weeks cause I've got a ton of studying with finals.
Cheers,
Phil
I'll chime in, this looks interesting!
10k resistor to output of the LFO op-amp.
(Also please keep the inductor there, did a simulation in LTspice, it creates a nice resonant lowpass-filter with a cutoff around some 3kHz if I remember correctly - but only resonant on the negative side.)
I'll be back on the next page ;)
(http://i998.photobucket.com/albums/af105/phil2004/OPOCcircuit_012.jpg)
Sounds interesting. Any chance you can post a screencap if you get it working?
EDIT: should we just throw in the whole LFO (no. 2) as one "component"
Just this once ::)
cheat!.. :icon_eek:
oh go on then... :icon_wink:
I told my coworker about this and he said there ought to be a Zener diode in there somewhere. :)
Screw studying for today...
(http://i998.photobucket.com/albums/af105/phil2004/OPOCcircuit_013.jpg)
I tried and succeeded in adding a zener ;D
Hope you like it!
Somebody ought to add a second 10u cap from pin 5 of the 1044 to GND so we have bipolar power already.
Not me though. I already used up my turn. :)
Honestly, where does the zener go?
I've never used them before...
The 1044 is in limbo right now... I don't know if it'll be used
can i add an led and 470r from pin 1 of the 072 to ground....it worked on my phase 45 as a rate lfo indicator...
whether it will on this im not sure!.. :icon_wink:
Sounds good
Did adding it change anything at all?
OK I would like to make this really interesting by adding a SAD1024.
OMG ...
22n cap in series between the bottom of the 10u cap and ground in the LFO ;)
Did some simulations back at post #68:
(https://lh6.googleusercontent.com/_F7LHhLrjWLw/TaH5-AEswrI/AAAAAAAAAsY/_OPtXeDTr_c/s912/pic1.jpg)
This is with a +1/-1V sinus input at 220Hz
(https://lh4.googleusercontent.com/_F7LHhLrjWLw/TaH5-25bwQI/AAAAAAAAAsc/9gV34PAhRQ8/s912/pic2.jpg)
This with the 0r set to 100k
:o
Well I'm baffled... Looks cool though, maybe I'll pick up an inductor from the local place when I'm done exams, see what it sounds like with a guitar signal
Thanks!
You might want to put in a buffer in front of the circuit, if you are going with the current schem...
Good luck with your exams :)
(http://dudelol.com/DO-NOT-HOTLINK-IMAGES/Chest-Burster.jpg)
I'm back!
Forgot to order the less common components needed to build this, but I think I can test it out with similar components
I've got a 12V transformer from a pair of speakers and another unmarked transformer I yanked out of an RF booster, so maybe I can try those out. No idea what the inductance will be, but if they sound any good, I'll try measuring
Any ideas as to which winding makes a more suitable wah inductor? (Or if power transformers will work at all!?!)
Update:
It works!
Substituted
1) 2SK117 for the FET (doubt it changes much, as the gate isn't connected!)
2) Cable TV booster power transformer's secondary (low voltage side) for 470mH
3) Didn't bother adding 0R resistor
I also swapped a 1M for the 470k resistor to Vref at one point, as I had mistakenly put a 4.7k resistor and was not understanding why the volume was so low :-[
Sounds "fuzzier" than with the 470k... Going back to the original circuit, there's something funny going on when I play the high e and b strings... Don't know how to describe it and unfortunately I don't have the equipment to record, but its almost like really really fast, shallow vibrato?
Might mess around with this some more later, maybe breadboard the LFO as well
How about....
(http://i54.tinypic.com/2le6xj.gif)
--> lfo in --> led(s) -/-> ldr(s) --> ?
I like it!
I even have a DIY vactrol leftover from the tiny tremolo.
The 10n cap didn't do much going to ground, removing it gave a tiny bit more treble. I wonder what hooking it up to the emitter will do?
Ok this is driving me nuts:
Set it up with an LFO-controlled LED/LDR, from 10n to emitter. Sounded like a very shallow tremolo, so I upped the 10n to 47n and it became more pronounced. Then I tinkered with the bias and added a loud, distorted signal, and it started doing the strangest thing... sounded a like a harmonizer/octave down/ring mod. Something of the sort.
And then it went away, so I rebiased and there it was again!
And now I've lost the effect completely, and I have no clue as to why it was there in the first place... any ideas??
Up the cap to 100n and change the emitter resistor to 4k7. You should get some vibrato like the Wobbletron (well, who knows in the context of everything else that's going on in this thing).