Would you prefer one PCB with 3 VCOs a la JH-5A, or 1 VCO per PCB with more features |
One PCB with Oscillator Driver and 3 VCO cores (like JH-5A - cheap!) |
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60% |
[ 62 ] |
1 PCB = 1 VCO (with many waveforms and inputs) |
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39% |
[ 41 ] |
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Total Votes : 103 |
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The Bad Producer
Joined: Mar 08, 2009 Posts: 282 Location: The Manhole
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Posted: Sat Sep 04, 2010 8:12 am Post subject:
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thanks! Yes I do, but as it is not my circuit, as it were, not sure about the ethics of posting such a thing...?
It needs a bit of work to make it into a PDF though, so maybe I'll do that and in the meantime make an enquiry to the relevant peeps as to whether I can post it here...
charlie
EDIT - Doug says that is cool, so I'll post it up, tomorrow hopefully... _________________ http://loudestwarning.tumblr.com/ |
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JoeMorris
Joined: Apr 26, 2009 Posts: 161 Location: Brighton
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Posted: Sun Sep 05, 2010 4:22 am Post subject:
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nice one. id like to add those capabilities to my living vcos |
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LetterBeacon
Joined: Mar 18, 2008 Posts: 454 Location: London, UK
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Posted: Sun Sep 05, 2010 4:28 am Post subject:
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Great news! |
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The Bad Producer
Joined: Mar 08, 2009 Posts: 282 Location: The Manhole
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LetterBeacon
Joined: Mar 18, 2008 Posts: 454 Location: London, UK
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Posted: Sun Sep 05, 2010 11:12 am Post subject:
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The Bad Producer wrote: |
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Whereabouts did you get the frequency knobs and the linear detune knobs from? They look great! |
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The Bad Producer
Joined: Mar 08, 2009 Posts: 282 Location: The Manhole
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Luka
Joined: Jun 29, 2007 Posts: 1003 Location: Melb.
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The Bad Producer
Joined: Mar 08, 2009 Posts: 282 Location: The Manhole
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Posted: Mon Sep 06, 2010 5:49 am Post subject:
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Okay, got my hard drive and the files.
I've attached the stripboard layout for Electronic Peasants Waveshaper, also on the PDF is a stripboard layout for the pulse amplifier, copied from JH's schematic for the saw output. I have not included decoupling caps, I just used a couple of 10uF electro's and a couple of 100NF on the power rails.
Please double check everything, I have built quite a few of these, but there may still be errors. Also, I used multiturn in-line trimpots, it gets a bit tight with these - I wanted the layout to be as small as possible - so double check that the ones you have will fit.
Another thing I noticed when I tested the first one, if you haven't got all the trimmers (esp the saw offset) set correctly there will be no output, I went through prodding with the oscilloscope as I went to calibrate it, but it does work and works very well too!
Charlie
PS I hope you don't mind the graphic 'style' it seems clear to me!
PPS The schematic is from Electronic Peasants post on page 12 of this thread...
Description: |
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Download |
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Living VCO Waveshaper Stripboard.pdf |
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103.21 KB |
Downloaded: |
892 Time(s) |
_________________ http://loudestwarning.tumblr.com/ |
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LetterBeacon
Joined: Mar 18, 2008 Posts: 454 Location: London, UK
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Posted: Mon Sep 06, 2010 6:29 am Post subject:
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That's perfect - thank you very much! |
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Luka
Joined: Jun 29, 2007 Posts: 1003 Location: Melb.
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The Bad Producer
Joined: Mar 08, 2009 Posts: 282 Location: The Manhole
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jhaible
Joined: May 25, 2007 Posts: 2014 Location: Germany
Audio files: 24
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Posted: Tue Sep 14, 2010 11:39 pm Post subject:
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The Bad Producer wrote: | Thanks!
Made a track using just Living VCO's (and some envelopes etc - no filters though)
here:
http://soundcloud.com/thebadproducer/stranglehold
I quite like the hissing and bass etc...
(its not a bad recording that is the VCO's too... VHF I guess... I like) |
The noises fit beautifully into the musical context, but for general use you should get rid of them, I guess. Do you have bypass caps on the opamps of your waveshaper board?
JH. _________________ "I tell you the truth, if anyone says to this mountain, 'Go, throw yourself into the sea,' and does not doubt in his heart but believes that what he says will happen, it will be done for him. Therefore I tell you, whatever you ask for in prayer, believe that you have received it, and it will be yours." (Mk 11,23f) |
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The Bad Producer
Joined: Mar 08, 2009 Posts: 282 Location: The Manhole
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Posted: Wed Sep 15, 2010 3:09 am Post subject:
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Yes, I have bypass caps on the waveshapers (they're not on the stripboard layout though).
It is quite interesting the noise - I have no idea where it comes from, maybe you would understand this more?
Basically they only occur when I set the frequency 10 turn pot all the way up as far as it will go and then use CV to send the frequency higher with a gate or trigger, if the frequency knob is even slightly away from fully CW it does not happen - I always thought it was some kind of glitch with the wirewound 10 turn pots?
But as I said, it never occurs in normal operation, they are clean as you like!
I quite like it though, I stumbled across it when I tried processing a friends guitar through the FM input and seeing what happened... It also reminds me a bit of Pole, who - legend has it - dropped his filter unit and when he turned it on again created all those pops and clicks which defined his oeuvre... So maybe it isn't supposed to do that!
I repaired a friends Plan B Elf LFO recently and that also goes VHF a bit like this, but not so 'musically' _________________ http://loudestwarning.tumblr.com/ |
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jumunius
Joined: Apr 19, 2010 Posts: 346 Location: San Francisco, CA
Audio files: 13
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Posted: Wed Sep 15, 2010 9:04 pm Post subject:
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The Bad Producer wrote: | Basically they only occur when I set the frequency 10 turn pot all the way up as far as it will go and then use CV to send the frequency higher with a gate or trigger, if the frequency knob is even slightly away from fully CW it does not happen - I always thought it was some kind of glitch with the wirewound 10 turn pots?
But as I said, it never occurs in normal operation, they are clean as you like!
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I must say I am relieved that you clarified this. I knew the Living VCOs were supposed to be "imperfect" in terms of tracking, but I expected better signal to noise ratio than your track implied. As a proud owner of two empty boards, I'm glad to hear that even if it is normal behavior, it's only occurring at an abnormal setting.
Other than that I quite enjoyed your glitchy noise bursts. |
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The Bad Producer
Joined: Mar 08, 2009 Posts: 282 Location: The Manhole
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Posted: Thu Sep 16, 2010 4:54 am Post subject:
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Yes, Just to clarify, they sound amazingly clean, track well etc, in fact the ideal oscillators! There is no 'noise' in normal useage at all... eg the sub-bass is from the same Living VCO unit playing at the same time, no noise there!
I just found this odd 'function' (well odd and new to me!) which as I said, seems to be a glitch with the pots I'm using and using the osc (with FM) at extreme high frequencies (at least that is how it looks to me!) _________________ http://loudestwarning.tumblr.com/ |
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defex
Joined: Jun 27, 2008 Posts: 36 Location: Toronto, canada
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Posted: Thu Sep 16, 2010 10:33 am Post subject:
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Just a quick question. I am not using the linear detune input on the second oscillator, can the input be left floating? or should i put a jumper on that connector to ground?
In this version I have a mix control/amplifier between saw/pulse of each section, and the individual outs are normalled to the FM inputs in a 1-2 2-3 3-1 fashion.
so far each osc has been tested and working, i am just finishing up the mixer/amplifier part and the lots and lots of wiring! |
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jhaible
Joined: May 25, 2007 Posts: 2014 Location: Germany
Audio files: 24
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Posted: Thu Sep 16, 2010 11:17 am Post subject:
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defex wrote: | Just a quick question. I am not using the linear detune input on the second oscillator, can the input be left floating? or should i put a jumper on that connector to ground?
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You can leave that open.
JH. _________________ "I tell you the truth, if anyone says to this mountain, 'Go, throw yourself into the sea,' and does not doubt in his heart but believes that what he says will happen, it will be done for him. Therefore I tell you, whatever you ask for in prayer, believe that you have received it, and it will be yours." (Mk 11,23f) |
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defex
Joined: Jun 27, 2008 Posts: 36 Location: Toronto, canada
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Posted: Fri Sep 17, 2010 12:19 pm Post subject:
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Thank you for the quick reply! |
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defex
Joined: Jun 27, 2008 Posts: 36 Location: Toronto, canada
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Posted: Mon Sep 20, 2010 7:36 pm Post subject:
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Although not as ambitious as the waveshaper, I have replaced the saw/pulse switches with 50k pots, and it is well worth it, you can fade between saw and pulse for each oscillator.
(it has screwed up the text of my lovely FPE panel, but worth it for the extra feature)
just connect each end of the pot to where it says "pulse" and "saw" on wiring option 3, and the wiper to the common side of the switch.
this will probably only work if you are using wiring option 3 because you would end up with a high impedance output if the pot was not in front of the "amp" sections.
If using BL conductive plastic pots, they do not go all the way down to 0 ohms (the ones i tried anyways) so you get a little tiny bit of pulse left on the saw even when it is cranked all the way over to "saw", with carbon pots it did not happen. |
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defex
Joined: Jun 27, 2008 Posts: 36 Location: Toronto, canada
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Posted: Fri Sep 24, 2010 7:07 pm Post subject:
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Yet another question.
I have decided to cut or switch the connection between the LFO to the CV out of the main pitch CV section (r142), and use it for a PWM LFO instead (with a separate buffer like the U11b Drvout one) but i want to slow down the LFO , I am guessing i can just increase the value of c31 to accomplish that, is that correct? |
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jhaible
Joined: May 25, 2007 Posts: 2014 Location: Germany
Audio files: 24
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Posted: Sat Sep 25, 2010 2:33 am Post subject:
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defex wrote: | Yet another question.
I have decided to cut or switch the connection between the LFO to the CV out of the main pitch CV section (r142), and use it for a PWM LFO instead (with a separate buffer like the U11b Drvout one) but i want to slow down the LFO , I am guessing i can just increase the value of c31 to accomplish that, is that correct? |
It's fairly trivial to build an LFO that covers a wide frequency range - but *this* war especially tailored to have a small frequency range, dedicated to typical Vibrato applications.
You can always make an LFO slower by increasing the integration cap, or integration resistor. But that won't defeat the (intentional) range limitation - you'd just scale the whole range down.
So if you want to (ab)use that generator as a general purpose wide-range LFO, 1st thing is vastly increasing R151. Try 10Meg here, and only if it's still too fast for your taste, increase C31.
JH. _________________ "I tell you the truth, if anyone says to this mountain, 'Go, throw yourself into the sea,' and does not doubt in his heart but believes that what he says will happen, it will be done for him. Therefore I tell you, whatever you ask for in prayer, believe that you have received it, and it will be yours." (Mk 11,23f) |
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kjackman
Joined: Sep 05, 2010 Posts: 69 Location: Utah, USA
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Posted: Sun Oct 10, 2010 3:41 pm Post subject:
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A bit of a newbie here, so bear with me...
CA3046 is increasingly hard to find these days, and I'm guessing it's just going to get harder as time goes on. Would a precisely matched pair of general-purpose NPN transistors, connected as a differential pair, in thermal contact, work just as well? For example, two 2N3904s Vbe-matched to within 1mV, with thermal compound between them and tied together with a cable tie? I'd have to thermally connect them to the Tempco as well, of course...
Also, what does connecting pin 13 of U2 (the "substrate") do? Schematically, this is just the emitter of Q5, which is not used in your circuit.
I know I can get 3046's from Bridechamber for $1 (today, yes; tomorrow? Who knows!). I Just want to make sure we can continue to build and maintain these VCOs long after the apocalypse, when the zombies hoard the last of our precious analog ICs.
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jhaible
Joined: May 25, 2007 Posts: 2014 Location: Germany
Audio files: 24
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Posted: Sun Oct 10, 2010 8:41 pm Post subject:
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kjackman wrote: | A bit of a newbie here, so bear with me...
CA3046 is increasingly hard to find these days, and I'm guessing it's just going to get harder as time goes on. Would a precisely matched pair of general-purpose NPN transistors, connected as a differential pair, in thermal contact, work just as well? For example, two 2N3904s Vbe-matched to within 1mV, with thermal compound between them and tied together with a cable tie? I'd have to thermally connect them to the Tempco as well, of course...
Also, what does connecting pin 13 of U2 (the "substrate") do? Schematically, this is just the emitter of Q5, which is not used in your circuit.
I know I can get 3046's from Bridechamber for $1 (today, yes; tomorrow? Who knows!). I Just want to make sure we can continue to build and maintain these VCOs long after the apocalypse, when the zombies hoard the last of our precious analog ICs.
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I haven't tried it, but a pair of discrete transistors should work. No idea if a cable tie is good enough for thermal connection - I'd use something thermally conduction, like copper wire, instead. Try and find out for yourself, if it's good enough for you. VCO will work with about any decent transistor pair - drift and tuning stability will vary.
Don't expect the LV to work after the apocalypse, though, 3046 or not.
JH. _________________ "I tell you the truth, if anyone says to this mountain, 'Go, throw yourself into the sea,' and does not doubt in his heart but believes that what he says will happen, it will be done for him. Therefore I tell you, whatever you ask for in prayer, believe that you have received it, and it will be yours." (Mk 11,23f) |
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MR-808
Joined: Sep 30, 2010 Posts: 28 Location: Portland, OR
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MR-808
Joined: Sep 30, 2010 Posts: 28 Location: Portland, OR
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Posted: Mon Oct 25, 2010 6:56 pm Post subject:
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Has anyone found that they actually need the trim pots on the front panel? |
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