1. Analog Synthesizers Yohahn Jo Systems Engineering Class of 2011

2. Analog Synthesizer 60s ~ 80s Wave generating machine outputs sound Through filters sounds are modified

3. Basic Features Voltage Controlled Oscillator Voltage Controlled Filter Voltage Controlled Amplifier Mixer

4. Filters Use filters to modify the sounds Three commonly used filters: low pass, high pass, band pass http://www.hobbyprojects.com/general_theory/images/filter3.gif

5. Example: Ideal Low Pass Filter H( ω ) = Frequency response h(t) = impulse response Sinc function extends to future and past times, therefore need an infinite delay to do the convolution

6. Envelop Generator Trigger and Gate signals Attack Decay Sustain Release (ADSR) http://www.scottliddell.com/uploaded_images/adsr-725469.png

7. Sample and Hold Uses an internal clock to capture a voltage level of the signal and hold it.

8. Other Modules Noise Generator Ring Modulator ◦ Multiplies two signals Voltage Processor

9. Analog Synthesizers… Are hard to use gives much more options in creating unique sounds Replaced by digital synthesizers Digital synthesizers are easier to use, but there are limitations in producing a unique sound

10. Classic Patch VCOVCFVCA Envelope GeneratorKeyboard GateTrigger

11. How To Make Sounds Analyze the sound in depth ◦ Listen carefully to the details Decide which modules to use Draw a diagram Test

12. Drum Machine Low frequency (VCO) Noise generator ADSR Envelope generator VCOVCFVCA Envelope Generator Noise Generator Sample and Hold

13. Questions

14. Works Cited http://www.intuitivedesigns.net/analog-vs-digital- pros-and-cons-in-digital-technology/ http://www.intuitivedesigns.net/analog-vs-digital- pros-and-cons-in-digital-technology/ http://cnx.org/content/m0028/latest/ http://www.guitarfool.com/ARP2600.html http://en.wikipedia.org/wiki/Impulse_response http://en.wikipedia.org/wiki/Low-pass_filter Class Notes by H. Mukai