1. Department of Electrical and Computer Engineering Theremi n THEREMIN

2. Theremin First electronic instrument influencing Moog and pioneers in musical electronics. Background Created by the Russian Inventor Leon Theremin in 1919. 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 pitch and volume.

3. Lack of Reference: Since the thereminist does not actually touch the theremin, he has no point of reference for tuning notes and nothing to steady his hand. Continuous Volume: Staccato playing or quick stops and starts are difficult with the theremin because of continuous volume control. Theremi n Continuous Pitch: The theremin is a continuous pitch instrument like trombone or violin which makes staying in tune difficult. Also the lack of any physical reference makes playing difficult to learn. Motivation

4. 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: A more versatile theremin will be able to switch from the original continuous frequency mode and a new discrete frequency mode that produces scales automatically.

5. Theremin Discrete Frequency Accuracy –Switchable between playing the traditional continuous range and playing only distinct frequencies in twelve selectable major scales with error < 0.1%. 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 a center frequency at 440Hz. Design Requirements Tuning –A 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.

6. Theremi n Design 1.Software Simulation PSPICE, MATLAB 2. Hardware Testing Breadboard circuits Analyze differences between simulation and lab results. 3. Update Simulations

7. Theremin Modular Design Variable Oscillator Fixed Oscillator Detector Pitch Control Variable Oscillator Volume Tuning Volume Control Freq Switch Theremin Tuner Out Signal Footswitch Audio Out Freq-Voltage Converter PIC controller with A/D Discrete Frequency Controller 14-bit D/A V/F Converter VCA Processor Voltage Controlled Amplifier Output Control

8. 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

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

10. Theremin Conclusions and Future Work Our.1% pitch error limit may be more stringent than needed. Some common tuners accept up to.2% pitch error. The discrete frequency output may have a different timbre than the continuous frequency output. A wave-shaping circuit could be added to give them similar quality.

11. Month 1Month 2Month 3Month 4 Month5Month 6Month 7Month 8 Semester One Semester Two Time Line Requirements Design Document Test CertificationTest Specification DocumentationHardware VerificationDesign/Simulation PackagingPresentations Simulation Final Design Document Theremin

12. Department of Electrical and Computer Engineering Theremi n THEREMIN

13. Requirements Circuit Simulation Antenna Test ExcelOscilloscopeTuner Prototype Testing Fixed Pitch Accuracy   Foot Switch    Frequency Range   Physical Attributes  Power  Signal Output  Tuner Out  Test Specification

14. Theremi n Discrete Mode Overview Frequency/Voltage Converter PIC controller with 10 bit A/D 14 bit D/A Converter Voltage/Frequency Converter 110-1760 Hz continuous beat frequency from detector 0.3-5 V continuous voltage range Binary representation of selected output level Resulting discrete voltage level Desired note within 0.045% error