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PHOBoS
Joined: Jan 14, 2010 Posts: 5591 Location: Moon Base
Audio files: 705
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Posted: Thu Mar 31, 2016 7:05 am Post subject:
Re: PHOBoS DIY Synth schematics Subject description: circuit pr0n! |
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All I know is that it is a 400mW zenerdiode, I don't have a serial number or anything but that shouldn't really matter.
The original circuit by Nicolas has V/Hz tracking but I don't know if that is still true with the modifications I made,
and no there isn't any calibration.
I see you are pretty new to this DIY stuff and personally I wouldn't recommend this VCO. It works but it's range is rather
limited (I originally made it to use in a drone synth) and a triangle output is pretty boring.
A sawtooth wave is more interesting and can easily be converted to triangle or square and a sinewave isn't very hard to do either.
So I would suggest to have a look at this thread and this one. And maybe the one posted here could be worth a try too. _________________ "My perf, it's full of holes!"
http://phobos.000space.com/
SoundCloud BandCamp MixCloud Stickney Synthyards Captain Collider Twitch YouTube |
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jurekprzezdziecki
Joined: Mar 22, 2016 Posts: 68 Location: warsaw
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Posted: Thu Mar 31, 2016 7:15 am Post subject:
Re: PHOBoS DIY Synth schematics Subject description: circuit pr0n! |
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PHOBoS wrote: | All I know is that it is a 400mW zenerdiode, I don't have a serial number or anything but that shouldn't really matter.
The original circuit by Nicolas has V/Hz tracking but I don't know if that is still true with the modifications I made,
and no there isn't any calibration.
I see you are pretty new to this DIY stuff and personally I wouldn't recommend this VCO. It works but it's range is rather
limited (I originally made it to use in a drone synth) and a triangle output is pretty boring.
A sawtooth wave is more interesting and can easily be converted to triangle or square and a sinewave isn't very hard to do either.
So I would suggest to have a look at this thread and this one. And maybe the one posted here could be worth a try too. |
thanks a lot for your suggestions. i will look for those designs. |
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mikemoretti
Joined: Apr 29, 2014 Posts: 5 Location: Boston, USA
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Posted: Wed Jan 11, 2017 8:14 pm Post subject:
VCF resonance voltage is high |
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I breadboarded the VCF here and whenever you turn up the resonance, the voltage doesn't stick to the +/-5v range but goes to -5 to +10v. Any ideas why this would happen or how to fix it?
Thanks!
-m |
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PHOBoS
Joined: Jan 14, 2010 Posts: 5591 Location: Moon Base
Audio files: 705
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Posted: Sat Jan 14, 2017 9:32 am Post subject:
Re: VCF resonance voltage is high |
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Although it is not unusual for a filter to have a higher output voltage when the resonance is turned up there shouldn't be any offset.
At least not when a symmetrical waveform is used. I did some tests with my own filter and with a triangle wave the output voltage
pretty much stays within the -5..+5V range, with a squarewave there are peaks that go beyond that but nothing asymmetrical.
I'm not sure if it has anything to do with it but did you use green LEDs and connect them the correct way around ? Also, what kind
of input signal are you using ? _________________ "My perf, it's full of holes!"
http://phobos.000space.com/
SoundCloud BandCamp MixCloud Stickney Synthyards Captain Collider Twitch YouTube |
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mikemoretti
Joined: Apr 29, 2014 Posts: 5 Location: Boston, USA
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Posted: Sat Jan 14, 2017 3:20 pm Post subject:
It was the LEDs |
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I hadn't added the leds. I didn't think they matter, but I guess their ~3v voltage drop across them is actually important. Now, it's down to about +/-7v with resonance all the way up and doesn't have any DC shift. I tried it out on saw and triangle. This is great! Thanks! |
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PHOBoS
Joined: Jan 14, 2010 Posts: 5591 Location: Moon Base
Audio files: 705
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J-chot
Joined: Jan 20, 2014 Posts: 44 Location: Decatur AL
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Posted: Sun Sep 23, 2018 11:09 am Post subject:
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where the hell did you get a 9v2 zener Diode?... is that supposed to be 9v1? |
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PHOBoS
Joined: Jan 14, 2010 Posts: 5591 Location: Moon Base
Audio files: 705
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J-chot
Joined: Jan 20, 2014 Posts: 44 Location: Decatur AL
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Posted: Mon Sep 24, 2018 1:16 pm Post subject:
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PHOBoS wrote: | I believe you are correct, or maybe it was a 8V2. The value isn't critical though as the actual voltage can be adjusted.
Just don't make it too high because than it doesn' t work anymore. |
thank you so much, because I was really thrown for a loop there for a sec, lol. |
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