1. Mississippi State University Department of Electrical and Computer Engineering Theremi n THEREMIN

2. Douglas Beard dtb4@ra.msstate.edu Micah Caudle Msc1@ece.msstate.edu Jeffrey Jun-Fey Wong jw5@ra.msstate.edu Way Beng Koay wk4@ece.msstate.edu Dr. Raymond Winton Faculty Advisor Theremin Team Members

3. Theremi n Responsibilities Douglas Beard:  Discrete Frequency Hardware Micah Caudle:  Pitch and Volume Control Hardware  Tuner Out Circuit Way Beng Koay:  Discrete Frequency Hardware Jeffrey Jun-Fey Wong:  Output Stage  Footswitch Circuit

4. Theremin First electronic instrument influencing Moog and pioneers in musical electronics. Background Created by the Russian Inventor Leon Theremin in 1919. Uses heterodyning to create audible frequencies from the difference of two high frequency oscillators. The thereminist does not actually touch the theremin except to mute it. Controlled by capacitance between hands to antennas. Placement of the hands relative to antennas controls this capacitance.

5. Theremin How Does It Work? Variable Oscillator Fixed Oscillator Detector Pitch Control Variable Oscillator Volume Tuning Volume Control VCA Processor Voltage Controlled Amplifier Output Control

6. Theremi n Currently:  Quality theremins are too expensive. $369-3,500  Limited playing style prevents broad use. Horror Movies Sound Effects  Too difficult to play well. No Physical Reference Motivation

7. Theremin Lack of Reference : Since the thereminist does not actually touch the theremin, the thereminist has no point of reference for notes and nothing to steady his or her hand. Problems Continuous Pitch : The theremin is a continuous pitch instrument like trombone or violin which makes staying in tune difficult. This fact makes theremin difficult to learn, but it also produces some desired effects. Continuous Volume : Staccato playing or quick stops and starts are difficult with the theremin because of continuous volume.

8. Theremin Tuning: A reference for tuning will be provided for silently locating starting pitches and pitch verification during practice. Theremin will interface with common tuners. Solutions Foot Pedal: A foot pedal will allow instantaneous mute and unmute in order to produce easier staccato. Dual Mode Theremin : The theremin will be able to switch from the original continuous frequency mode and a new discrete frequency mode.

9. Theremin Continuous/Discrete Frequency Control –Switchable between playing the traditional continuous range and playing only distinct frequencies in selectable scales with error < 0.1%. Tuning –A small amplitude signal will always be present at the 1/4" tuner out jack to enable the performer to locate starting pitches and for pitch verification during practice. Precise Articulation –A footswitch will connect to the theremin to enable the performer to quickly and easily articulate notes. Frequency Range –A frequency range of four octaves with adjustable center frequency set to a default value of middle C at 262Hz. Design Requirements

10. Theremin Continuous/Discrete Frequency Control Discrete Frequency Controller Fixed Oscillator Variable Oscillator Summing Volume Control & Audio Output Antenna Switch

11. Continuous Discrete Key b # A B C D E F G Chromatic Continuous Mode  Traditional Operation  Key Circuitry Bypassed Discrete Mode  Chromatic  Bypass Right Selector Switch Theremin Front Panel: Frequency Controls Discrete Mode  B Flat Scale Bb C D Eb F G A

12. Theremin Tuning Theremin Sabine STX-1100 A. B C. D. E F. G. FLAT IN TUNE SHARP

13. Theremin Modular Design Variable Oscillator Fixed Oscillator Detector Pitch Control Freq-Voltage Converter Voltage Comparator Voltage-Freq Converter Discrete Frequency Controller Variable Oscillator Volume Tuning Volume Control VCA Processor Voltage Controlled Amplifier Output Control Freq Switch Theremin Tuner Out Signal Footswitch Amplifier Signal

14. Theremin REQUIREMENTSANTENNA SIMULATION CIRCUIT DESIGN & SIMULATION LABORATORY EVALUATION Pitch Oscillator Ckt  Volume Control Ckt  Antenna Capacitance  Fixed Pitch Accuracy  Frequency Range  Tuner Out Ckt  Foot Switch Ckt  Power Supply  Cost  Test Specifications

15. AugSeptOctNovDec Objective4512345123451234512 Documentation Presentation Research Design Simulation Prototype Design Module A Pitch Control B Volume Control C Discrete Freq Controller D Output Control Douglas Beard Jeffrey Jun-Fey WongWay Beng KoayMicah Caudle Theremin AB RequirementTest SpecDesignTest CertFinal A & B C D D D C C Preliminary Design ReviewDesign Review A & B

16. Theremin References [1]J. Rothman, "Simple Theremin," Everyday Practical Electronics, vol. 24, no. 9, September 1995. [2]B. Suits, "Physics of Music", http://www.phy.mtu.edu/~suits/notefreqs.html, Physics Department, Michigan Technological University, Houghton, Michigan, USA. [3]"Sabine Professional Audio and Music Accessories “ http://www.sabineusa.com/index.html, Sabine, Inc., Alachua, FL, USA, August 2000. [4]E. J. Schultz, “A Simple Electronic Musical Instrument – The Theremin,” Radio and Television News, pp. 84-86, October 1949. [5]A. Harrison, “The Wien-Bridge Theremin,” http://home.att.net/~theremin1/Wien/wien.html, October 1999. [6]L. E. Garner, Jr., “For That Different Sound, Music a la Theremin,” Popular Electronics, November 1967. [7]R. Moog, "Build the EM Theremin," Electronic Musician, pp. 86-100, February 1996.

17. Theremin References [8]R. Moog, "A Transistorized Theremin," Electronics World, vol. 65, no. 1, pp. 29-32, 125, January 1961. [9]G. Velasquez, "The Aria," Wescon/97 IEEE Conference Proceedings, pp. 527- 530, November 1997. [10]C. A. Balanis, Antenna Theory Analysis and Design, John Wiley & Sons, Inc., New York, New York, USA, 1997.