Analog SynthesizersAnalog Synthesizers

Yohahn JoSystems Engineering

Class of 2011

Analog SynthesizerAnalog Synthesizer60s ~ 80sWave generating machineoutputs soundThrough filters sounds are

modified

Basic FeaturesBasic FeaturesVoltage Controlled OscillatorVoltage Controlled FilterVoltage Controlled AmplifierMixer

FiltersFilters

Use filters to modify the soundsThree commonly used filters: low

pass, high pass, band pass

http://www.hobbyprojects.com/general_theory/images/filter3.gif

Example: Ideal Low Pass Example: Ideal Low Pass FilterFilterH(ω) = Frequency responseh(t) = impulse response

Sinc function extends to future and past times, therefore need an infinite delay to do the convolution

Envelop GeneratorEnvelop GeneratorTrigger and Gate signalsAttack Decay Sustain Release

(ADSR)

http://www.scottliddell.com/uploaded_images/adsr-725469.png

Sample and HoldSample and HoldUses an internal clock to capture

a voltage level of the signal and hold it.

Other ModulesOther ModulesNoise GeneratorRing Modulator

◦Multiplies two signalsVoltage Processor

Analog Synthesizers…Analog Synthesizers…Are hard to usegives much more options in

creating unique soundsReplaced by digital synthesizersDigital synthesizers are easier to

use, but there are limitations in producing a unique sound

Classic PatchClassic Patch

VCO VCF VCA

Envelope GeneratorKeyboard

Gate Trigger

How To Make SoundsHow To Make SoundsAnalyze the sound in depth

◦Listen carefully to the detailsDecide which modules to useDraw a diagramTest

Drum MachineDrum MachineLow frequency (VCO)Noise generatorADSR Envelope generator

VCO VCF VCA

Envelope

Generator

Noise Generat

or

Sample and Hold

QuestionsQuestions

Works CitedWorks Citedhttp://www.intuitivedesigns.net/analog-

vs-digital-pros-and-cons-in-digital-technology/

http://cnx.org/content/m0028/latest/http://www.guitarfool.com/

ARP2600.htmlhttp://en.wikipedia.org/wiki/

Impulse_responsehttp://en.wikipedia.org/wiki/Low-

pass_filterClass Notes by H. Mukai