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project:diy_synth:start [2016/11/25 08:12] – ↷ Page moved and renamed from project:diy_synth to project:diy_synth:start ruzaproject:diy_synth:start [2016/11/28 01:46] (current) – ruza
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 ====== Modular Synth ====== ====== Modular Synth ======
-{{template>infobox|+{{template>:project:infobox|
 name=DIY Modular Synth aka Samohrajka| name=DIY Modular Synth aka Samohrajka|
 image=electribe-blue.jpg?200| image=electribe-blue.jpg?200|
 founder=[[user:harvie]]| founder=[[user:harvie]]|
-status=testing & designing circuits}}+status=suspended}} 
 + 
 +~~META: 
 +status = suspended 
 +&relation firstimage = :project:electribe-blue.jpg 
 +~~
  
 Goals of this project: Goals of this project:
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   * Synths   * Synths
     * Consumer-ready     * Consumer-ready
-      * [[http://korg.com/Product.aspx?pd=571|Monotron]] seems to be cheap and hackable device. {{monotron_schematic.pdf}}+      * [[http://korg.com/Product.aspx?pd=571|Monotron]] seems to be cheap and hackable device. {{..:monotron_schematic.pdf}}
     * CCC 2010     * CCC 2010
       * http://syso.name/w/Main_Page       * http://syso.name/w/Main_Page
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 ==== Simplest Possible CMOS/MOSFET LFO ==== ==== Simplest Possible CMOS/MOSFET LFO ====
 CMOS oscillators are not capable of generating analogue signal on their output, but the voltage on capacitor of those oscillators is purely analogue. You can see what i've captured using soundcard attached directly to the capacitor of my "CMOScillator": CMOS oscillators are not capable of generating analogue signal on their output, but the voltage on capacitor of those oscillators is purely analogue. You can see what i've captured using soundcard attached directly to the capacitor of my "CMOScillator":
-{{ cmos_oscillator_capacitor_voltage.png?600 }}+{{ ..:cmos_oscillator_capacitor_voltage.png?600 }}
 So we can use MOSFET to amplify the voltage on such capacitor and voila - we have analogue LFO!!! (I've chosed MOSFET because CMOS logic is made from MOSFETs and because current can flow in both directions through the MOSFET, so we can use it to drive another "CMOScillator" directly). So we can use MOSFET to amplify the voltage on such capacitor and voila - we have analogue LFO!!! (I've chosed MOSFET because CMOS logic is made from MOSFETs and because current can flow in both directions through the MOSFET, so we can use it to drive another "CMOScillator" directly).
  
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 Schematic of simple VCO using CMOS 4046. Note that i am attaching VCO input directly to positive pin of LFO capacitor (instead of voltage-divider shown in picture), so i can drive the VCO using almost-saw signal from 4093 oscillator. Also note that 4046 VCO (thanks to voltage-driven MOSFET/CMOS technology) does not suck almost any current from the LFO capacitor, so it does not detune it (and i do NOT need any external discrete MOSFET transistor to amplify that signal as originaly wanted to do). Schematic of simple VCO using CMOS 4046. Note that i am attaching VCO input directly to positive pin of LFO capacitor (instead of voltage-divider shown in picture), so i can drive the VCO using almost-saw signal from 4093 oscillator. Also note that 4046 VCO (thanks to voltage-driven MOSFET/CMOS technology) does not suck almost any current from the LFO capacitor, so it does not detune it (and i do NOT need any external discrete MOSFET transistor to amplify that signal as originaly wanted to do).
-{{ 4046-vco.png }}+{{ ..:4046-vco.png }}
  
 Here you can see some signals from VCO (upper graph) and LFO (lower graph) that i've caputred using soundcard and audacity: Here you can see some signals from VCO (upper graph) and LFO (lower graph) that i've caputred using soundcard and audacity:
  
-  - **triangle wave** (LFO capacitor is both **charged and discharged through resistor**) {{ triangle.png?500 }} +  - **triangle wave** (LFO capacitor is both **charged and discharged through resistor**) {{ ..:triangle.png?500 }} 
-  - **saw down** (BassDrum / Kick) (LFO capacitor is **quickly charged** using LED/Diode bypass parallel to resitor) {{ saw-down.png?500 }} +  - **saw down** (BassDrum / Kick) (LFO capacitor is **quickly charged** using LED/Diode bypass parallel to resitor) {{ ..:saw-down.png?500 }} 
-  - **saw up** (LFO capacitor is **quickly discharged** using LED/Diode bypass parallel to resitor) {{ saw-up.png?500 }}+  - **saw up** (LFO capacitor is **quickly discharged** using LED/Diode bypass parallel to resitor) {{ ..:saw-up.png?500 }}
  
  
project/diy_synth/start.1480061540.txt.gz · Last modified: 2016/11/25 08:12 by ruza