Instructor: Prof. Aaron Lanterman
Office: Centergy 5212 (but I'm rarely there)
Phone: 404-385-2548
E-mail: lanterma@ece.gatech.edu (best way to reach me)
Course website: users.ece.gatech.edu/~lanterma/ems

When and where: TuTh, 12:05-1:25, Van Leer C341

The photo: Xavier, Aaron, and Christine showing off Xavier+Christine's design for a voltage-controlled phaser (from Spring 2006)

(Note: I often abbreviate the class title as "EMS." This usage of "EMS" should not be confused with "EMS" as in Electronic Music Studios, the makers of many classic synthesizers such as the Synthis.)

Aaron's SDIY Pages

• Synth DIY Datasheet and Ap Note Collection
• Music synthesis patents collection, with some brief commentary
• Current modular synth manufacturers - look through these to get ideas for your own new designs, ideas for packaging, etc.

Homeworks

• Homework 1 (due Tues, Feb. 12)
• Homework 2 (due Tues, Feb. 28)
• Homework 3 (due Thurs, March 13)
• Homework 4 (due Tues, April 8)

Lectures

• Session 1: 40 Years of Music Synthesis, Day 1 (Moog/Buchla up to DX7) (video)
• Session 2: 40 Years of Music Synthesis, Day 2 (DX7 and after) (video)
• Session 3: Op-Amp Review, Day 1 (video)
• Session 4: Op-Amp Review, Day 2 (video)
• Session 5: Meet the Korg MS-20, a typical semimodular analog monosynth (video)
• Session 6: Operation Transconductance Amplifiers (OTA), Voltage Controlled Amplifiers (VCA) (video)
• Session 7: Voltage Controlled Oscillators (Sawtooth Cores) (video)
• Session 8: Exponential Current Sources (video)
• Session 9: Voltage Controlled Oscillators (Triangle Core) (video)
• Session 10: Circuits for Simple Waveshaping (sorry no video available)
  • Related to circuits shown in class:
    • R. Williams, Triangle to Sine Conversion with OTAs
    • M.H. Miller, Triangle to Sine Conversion (Nonlinear Function Fitting), ECE414 Notes
    • R.G. Meyer, W.M.C. Sansen, S. Lui, S. Peeters, The Differential Pair as a Triangle-Sine Wave Converter, IEEE J. of Solid-State Circuits, June 1976, pp. 418-420.
    • G. Klein, Accurate Triangle-Sine Converter, IEEE International Solid-State Circuits Conference, Digest of Technical Papers, Volume X, Feb. 1967, pp. 120-121.
  • Other ideas:
    • H. Hassan, FET Differential Amplifier as a Tri-Wave to Sine Converter, Proc. 36th Southeastern Symposium on System Theory, 2004, pp. 427-430
    • Z. Tang, O. Ishizuka, H. Matsumoto, MOS Triangle-to-Sine Wave Convertor Based on Subthreshold Operation, Electronics Letters, Vo. 26, No. 23, Nov. 8, 1990, pp. 1983-1985.
• Session 11: Circuits for Complex Waveshaping (Ken Stone's wavefolder, Buchla's diodeless deadband circuit, Buchla's timbre circuit) (video)
• Session 12: Aliasing Dangers in Digital Oscillators, and Chebychev Waveshaping (video)
  • T. Stilson and J. Smith, Alias-Free Digital Synthesis of Classic Analog Waveforms, International Computer Music Conference, 1996.
  • V. Valimaki, Discrete-Time Synthesis of the Sawtooth Waveform with Reduced Aliasing, IEEE Signal Processing Letters, Vol. 12, No. 3, March 2005, pp. 214-217.
• Session 13: Oscillator Sync and Frequency Modulation (video)
  • E. Brandt, Hard Sync Without Aliasing
• Session 14: OTA-C single-pole voltage controlled filters (video)
  • Oberheim/Rossum patent, Circuit for Dynamic Control of Phase Shift
  • ARP patent, Frequency Sensitive Circuit Employing Variable Transconductance Circuit
• Session 15: Four-pole VCFs, Day 1 (video)
  • N-Pole Filter Circuit Having Cascaded Filter Sections - careful, the resonance feedback path drawn on the first page is in error! It should be going to the negative terminal of the first OTA on the left.
• Session 16: Four-pole VCFs, Day 2 (video)
  • Moog patent, Electronic High-Pass and Low-Pass Filters Employing the Bass to Emitter Diode Resistance of Bipolar Transistors
  • T. Stilson and J. O. Smith, Analyzing the Moog VCF with Considerations for Digital Implementation, Proceedings of the 1996 International Computer Music Conference, pp. 398-401.
  • A. Huovilainen, Non-Linear Digital Implementation of the Moog Ladder Filter, Proc. of the 7th Int. Conf. on Digital Audio Effects (DAFx'04), Naples, Italy, Oct. 5-8, 2004.
  • T.E. Stinchcombe, Derivation of the Transfer Function of the Moog Ladder Filter, July 5, 2005
• Session 17: Four-pole VCFs, Day 3 (video)
• Session 18: Four-pole VCFs, Day 4 (video)
• Session 19: Properties of Second-Order Filters (video)
• Session 20: More Properties of Second-Order Filters, and State Variable Filters (video)
  • MIT 2.161 Signal Processing notes, Op-Amp Implementation of Analog Filters using the State-Variable Approach
  • Analog Devices Interactive Design Tools: OpAmps: Active Filter Synthesis
  • R. Johnson, Programmable State-Variable Filter Design For a Feedback Systems Web-Based Laboratory
  • Daycounter, Inc. Engineering Services, State Variable Filter Design Equations
• Session 21: Sallen-Key Filters (video)
  • T.E. Stinchcombe, A Study of the Korg MS10 & MS20 Filters, August 30, 2006
• Session 22: Odds and Ends (video)

References

• Hal Chamberlin, Musical Applications of Microprocessors, 2nd Edition, Hayden, 1982; if you get just one book, this is THE book to get. Although it has "microprocessors" in the title, it has a superb section on analog circuits. NOS (New Old Stock - meaning old, but unused) copies are available for purchase from Jeff Dec ($50 + shipping); e-mail jdec@mindspring.com
• Barry Klein, Electronic Music Circuits, SAM, 1982. Long out of print, but photocopies can be purchased directly from barry.l.klein@wdc.com
• V. Valimaki and A. Huovilainen, Oscillator and Filter Algorithms for Virtual Analog Synthesis, Computer Music Journal, Vol. 30, No. 2, 2006, pp. 19-31.
• T. Stilson, Efficiently-Variable Non-Oversampled Algorithms in Virtual-Analog Music Synthesis, PhD Thesis, Standford University, June 2006.