Comments on: How-To: Make a digital synthesizer http://hackaday.com/2008/05/01/how-to-make-a-digital-synthesizer/ Fresh hacks every day Fri, 10 Feb 2012 17:43:10 +0000 hourly 1 http://wordpress.com/ By: Phil http://hackaday.com/2008/05/01/how-to-make-a-digital-synthesizer/comment-page-1/#comment-368180 Sat, 26 Mar 2011 18:43:55 +0000 http://hackaday.iheartcashews.com:8181/2008/05/01/how-to-make-a-digital-synthesizer/#comment-368180 yeah… it’s actually analog using a logic gate. the signal may be digital (on/off: square wave) but the pitch control is analog. if this were a truly digital synthesizer, the pitch control would be quantized giving you a finite amount of pitches.

]]> By: JustOneRobot http://hackaday.com/2008/05/01/how-to-make-a-digital-synthesizer/comment-page-1/#comment-362894 Sat, 19 Mar 2011 17:17:43 +0000 http://hackaday.iheartcashews.com:8181/2008/05/01/how-to-make-a-digital-synthesizer/#comment-362894 I built this thing and it’s pretty awesome. The issue I’m having is I want to mount everything in a portable case with its own speaker, but I don’t know exactly what I need to do so that it doesn’t need to go into powered speakers. This isn’t going to be a large speaker by any means, it just needs to be loud enough to have fun with it. I got it working using a very small piezo driver, but it’s really quiet. Right now the output is putting out .266 volts and I figure that’s probably not enough. Anyone got any suggestions?

@Bonham79 not sure if you’ve already gotten your answer, but it sounds like your issue could be using a stereo male with a mono female, or vice versa.

]]> By: ango http://hackaday.com/2008/05/01/how-to-make-a-digital-synthesizer/comment-page-1/#comment-340108 Wed, 23 Feb 2011 12:45:43 +0000 http://hackaday.iheartcashews.com:8181/2008/05/01/how-to-make-a-digital-synthesizer/#comment-340108 Hey, nice one. I’m goin to try it! Unfortunately,I can’t play the audioexamples, could you repost it somewhere, if they still exist?

]]> By: Harvie http://hackaday.com/2008/05/01/how-to-make-a-digital-synthesizer/comment-page-1/#comment-294850 Sun, 02 Jan 2011 13:40:35 +0000 http://hackaday.iheartcashews.com:8181/2008/05/01/how-to-make-a-digital-synthesizer/#comment-294850 Hi! I think that most simple way to make Analogue LFO Frequency Modulation is to attach MOSFET (or some similar amplifier) to capacitor which is driving the CMOS inverter (oscillator). The almost-sine-wave/almost-triangle signal is already there:

http://brmlab.cz/_detail/project/cmos_oscillator_capacitor_voltage.png

http://brmlab.cz/project/circuit_bending#simplest_possible_cmosmosfet_lfo

Note that MOSFET can be connected in parallel with the resistor/pot determining frequency of another oscillator.

]]> By: Harvie http://hackaday.com/2008/05/01/how-to-make-a-digital-synthesizer/comment-page-1/#comment-294849 Sun, 02 Jan 2011 13:38:54 +0000 http://hackaday.iheartcashews.com:8181/2008/05/01/how-to-make-a-digital-synthesizer/#comment-294849 Hi! I think that most simple way to make Analogue LFO Frequency Modulation is to attach MOSFET (or some similar amplifier) to capacitor which is driving the CMOS inverter (oscillator). The almost-sine-wave/almost-triangle signal is already there:

http://brmlab.cz/_detail/project/cmos_oscillator_capacitor_voltage.png

http://brmlab.cz/project/circuit_bending#simplest_possible_cmosmosfet_lfo

]]> By: Bonham79 http://hackaday.com/2008/05/01/how-to-make-a-digital-synthesizer/comment-page-1/#comment-219551 Sat, 27 Nov 2010 03:16:56 +0000 http://hackaday.iheartcashews.com:8181/2008/05/01/how-to-make-a-digital-synthesizer/#comment-219551 Can someone help me, i’ve wired up everything according to scamatics, but i’m not getting anything. I couldn’t find the right jack so i’m using a quarter inch phone jack, does that screw it up? I can only get sound if i pull the headphone slightly out.

]]> By: Lilly Braunwarth http://hackaday.com/2008/05/01/how-to-make-a-digital-synthesizer/comment-page-1/#comment-180105 Sat, 11 Sep 2010 06:44:20 +0000 http://hackaday.iheartcashews.com:8181/2008/05/01/how-to-make-a-digital-synthesizer/#comment-180105 Like the Nintendo Wii, there’s a piss-poor library for the DS

]]> By: andy http://hackaday.com/2008/05/01/how-to-make-a-digital-synthesizer/comment-page-1/#comment-142512 Sat, 15 May 2010 20:06:44 +0000 http://hackaday.iheartcashews.com:8181/2008/05/01/how-to-make-a-digital-synthesizer/#comment-142512 i can`t find the soundfiles in the flash players.
wanted to hear this melody once again :-)
is there another link?

]]> By: Dennis Cao http://hackaday.com/2008/05/01/how-to-make-a-digital-synthesizer/comment-page-1/#comment-124602 Thu, 18 Feb 2010 08:26:05 +0000 http://hackaday.iheartcashews.com:8181/2008/05/01/how-to-make-a-digital-synthesizer/#comment-124602 I just built this schematic as a first year ee student, havn’t taken a circuits class yet. It’s one thing to just build this but I really wanted to understand what was going on, so I talked to a professor who helped me out. Hope this helps anyone out. I’ll be referring to the last schematic with an LFO.

Basically what happens is that the 9V gets converted to 5V through the voltage regulator.

Then the 5V charges up the capacitor (plotted on a Voltage/time looks something like this except it only goes up to 5V http://www.kpsec.freeuk.com/images/charge.gif)

The HEX inverter has a THRESHOLD value that is somewhere inbetween 0 and 5V and when the capacitor (.1uf) has charged right above the threshold value, the output wave goes up and then comes back down when the capacitor starts to discharge and crosses the threshold value again.

The 100K potentiometer changes the audible frequency.
As for the LFO it is produced using a MOSFET transistor. The one in this case is an N type doped. It has a source, a drain and a gate (the middle pin). The transistor works as a switch that is triggered on an off by a voltage. An N type transistor opens when it is supplied by a positive voltage.

That is where the 1M pot, 1uf capacitor and HEX inverter come into play. They provide another output square voltage wave that triggers the MOSFET transistor to turn on and off. The tuning of the 1M pot gives a faster/slower square wave that determines how fast the MOSFET is triggered on/off and how quickly the two tones are heard. When the MOSFET transistor is turned off, the 50K potentiometer is not apart affecting anything. when the MOSFET is on the source and drain are connected and the 50k potentiometer is in effect. The pitch then alternates between two tones.

Hope this clears up and feel free to comment if I got anything wrong.

]]> By: Mike http://hackaday.com/2008/05/01/how-to-make-a-digital-synthesizer/comment-page-1/#comment-120420 Thu, 28 Jan 2010 16:21:50 +0000 http://hackaday.iheartcashews.com:8181/2008/05/01/how-to-make-a-digital-synthesizer/#comment-120420 @nick

Do you think you could send me a video of the first assembled schematic?
Seeing as you’re the most active visitor on this article currently.

it’s michaelman311@hotmail.com

]]> By: mike brazier http://hackaday.com/2008/05/01/how-to-make-a-digital-synthesizer/comment-page-1/#comment-120311 Thu, 28 Jan 2010 03:02:52 +0000 http://hackaday.iheartcashews.com:8181/2008/05/01/how-to-make-a-digital-synthesizer/#comment-120311 Please help me!
I’m doing this for my science fair project, and it won’t work properly.
I don’t know what’s wrong with it.

Could someone make a video on this?

Cheers,
Mike

]]> By: nick http://hackaday.com/2008/05/01/how-to-make-a-digital-synthesizer/comment-page-1/#comment-119337 Sun, 24 Jan 2010 18:21:35 +0000 http://hackaday.iheartcashews.com:8181/2008/05/01/how-to-make-a-digital-synthesizer/#comment-119337 err… having major problems with this… in th final image, is the picture or the chematic correct?

also, i have, i think got everything wired up, but only the 1M potentiometer does anything, and its all very quiet…

can someone post a picture of the finished article, so that i can see what im doing wrong?

thanks

]]> By: mister newbie returns http://hackaday.com/2008/05/01/how-to-make-a-digital-synthesizer/comment-page-1/#comment-115062 Tue, 05 Jan 2010 22:17:12 +0000 http://hackaday.iheartcashews.com:8181/2008/05/01/how-to-make-a-digital-synthesizer/#comment-115062 hi, i’m returning to confirm that the 47 resistor jameco link still hasn’t been changed to 47K resistor. (THANKS ilovegreenmonster) again, the current Jameco part# is 691260. the reason i’m doing this is that i thought i had a 47K when i actually had a 47. this caused me much confusion when i tried to use the leftover hack-a-day parts for a “weird sound generator” build. I highly recommend the “music from outer space” website for new synth builders. any suggestions for other sites with detailed walkthroughs of diy stompbox/synth builds, etc would be appreciated!

here is a resistor code calculator to make sure you have the proper parts: http://www.hobby-hour.com/electronics/resistorcalculator.php

]]> By: jamiewoody http://hackaday.com/2008/05/01/how-to-make-a-digital-synthesizer/comment-page-1/#comment-111685 Mon, 14 Dec 2009 17:19:05 +0000 http://hackaday.iheartcashews.com:8181/2008/05/01/how-to-make-a-digital-synthesizer/#comment-111685 if one were to install in input jack (for the purpose of daisy chaining multiple LFO synths), where would that go on the circuit?

]]> By: Micky http://hackaday.com/2008/05/01/how-to-make-a-digital-synthesizer/comment-page-1/#comment-110546 Sat, 05 Dec 2009 17:07:46 +0000 http://hackaday.iheartcashews.com:8181/2008/05/01/how-to-make-a-digital-synthesizer/#comment-110546 Is there an alternate schmitt trigger instead of the 40106 hex inverter??

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