Model 302 Theremin User Manual
(Back to 302 Theremin product description page)
Table of Contents
|Unpacking and Inspection|
|Additional Materials Required|
|Introduction to the Theremin|
|Model 302 Theremin Control Knobs and Output Jack|
|Setting Up the Model 302 Theremin|
|Playing the Model 302 Theremin|
|Grounding and Battery-Powered Amplifier Operation|
|Model 302 Theremin Specifications|
|Warranty and Repair Service|
|Contacting Harrison Instruments|
1. Safety Notices <back to contents>
Read all the instructions in this manual prior to using this product. Retain these operating instructions for future reference.
|When this product is connected to an external device such as an amplifier,
a shock hazard may be present.
To avoid electric shock, do not operate this product in the rain or near water.
Do not allow this product to become wet.
Do not replace or supplement this product's battery with an external power supply.
|Do not place cables connected to this product in areas where they can cause a trip hazard.|
|Do not play this instrument at a high volume, especially when using
Hearing experts advise against the continuous, extended use of headphones.
|Do not disassemble this instrument. There are no user serviceable
Refer servicing to qualified service personnel.
2. Unpacking and Inspection <back to contents>
The following items are contained in the carton:
Please retain the carton and all packing materials in the event the instrument has to be returned to Harrison Instruments for service.
Carefully remove the plastic wrapping from all items and inspect them for damage.
If damage is apparent:
PO BOX 9012
SILVER SPRING MD 20906
3. Additional Materials Required <back to contents>
The following items not supplied with the theremin are recommended for basic
4. Introduction to the Theremin <back to contents>
The theremin is named for its Russian inventor, Leon Theremin, who conceived of the instrument in 1918 and continued to developed it for several decades. It is one of the first electronic musical instruments, and has the distinction of being played by moving the hands within its proximity, without contact.
Theremins have two physical extensions called antennas. One of the antennas is used to control the pitch of the instrument's sound, and is referred to as the pitch antenna. The other is used to control the volume of the sound, and is referred to as the volume antenna. The pitch and volume produced by the theremin vary according to the capacitance between the hands and their respective antennas. The value of capacitance, in turn, is affected by the distance between each hand and its antenna.
The pitch-generating section of many theremins, including the Harrison Instruments Model 302, utilizes a principle called heterodyning, in which the signal from two inaudible, high-frequency oscillators are subtracted electronically to produce an audible difference frequency. One of the two high frequency oscillators provides a steady frequency, while the other oscillator's frequency is varied according to the change in capacitance between the hand and the pitch antenna. The volume-control section also uses changes in hand capacitance to alter the energy in a resonant circuit that, in turn, controls the loudness of the tone.
Many early designs of the theremin featured a vertical rod for the pitch antenna and a horizontal loop for the volume antenna. The 302 features two identical horizontal plates, one each for pitch and volume. The 302 also differs from traditional theremin designs in that the loudness of the tone increases as the hand is brought closer to the volume antenna, instead of becoming softer.
5. Model 302 Controls Knobs and Output Jack <back to contents>
The figure below identifies the front-panel features of the Model 302 Theremin.
To provide visibility, the labels for the knobs are located on the top of
the instrument. The OUTPUT JACK is located on the rear panel.
The following table describes the function of each feature.
Adjusts the response of the theremin's volume so that the tone is softest
with the hand furthest away from
Turns the theremin off in the fully-counterclockwise position, and adjusts
the theremin's maximum output
Indicates when the instrument is on, and will not light when the battery is weak or expired.
Adjusts the output tone characteristic from a low-harmonic, sine-like wave
(fully counterclockwise position)
Adjusts the response of the theremin's pitch so that the tone frequency is
lowest with the hand furthest
6. Battery Installation <back to contents>
The 302 Theremin uses one 9V alkaline battery such as Duracell® type MN1604. The battery compartment is located under the rectangular aluminum cover on the top of the instrument. To access the compartment, unscrew the two round aluminum bushings, set them aside, and remove the aluminum cover. The figure below shows the theremin with the battery compartment bushings and cover removed, and a battery installed. Note that the battery connector is firmly snapped onto the top of the battery, and that the POSITIVE (+) terminal of the battery is on the right.
To remove the battery, slide it toward the front panel to increase the space between the battery connector and the back of the instrument. Then, using your index finger, press against the top of the battery connector, and lift it upward. The battery will snap out of its holding clip. Grasp the battery between your thumb and index finger, and lift it out of the compartment. Be careful not to pull excessively on the battery connector wires. Remove the old battery by unsnapping the connector. Snap the new battery onto the connector, observing proper polarity, and snap the battery into the holding clip with the POSITIVE (+) terminal of the battery on the right. Replace the compartment cover and bushings. The bushings should be hand-tightened only; do not use pliers.
To prevent damage to the instrument from possible leakage or corrosion, do not leave the battery in the theremin for extended periods of non-use.
7. Setting Up the Model 302 Theremin <back to contents>
8. Playing the Model 302 Theremin <back to contents>
A few more steps must be performed before the theremin ready to play. First, it is important that the user is familiar with the following concept:
The output from the theremin is affected by the presence of any object,
including any part of your body, within about four feet of either of its
antennas. This means that your body position and body movement, and not just
your hand positions, will affect the output pitch and volume. The player
will not have exactly the same stance in front of the instrument each time,
and the theremin's proximity to large objects such as furniture or walls
will vary from one setup to another. Because of these factors, the theremin
must be adjusted to compensate for these variations before it is played,
as described in the following procedure.
In steps 1 through 3, the volume response will be adjusted:
To obtain more spacing between notes in the alto or soprano range, you may offset the PITCH ZERO knob by rotating it clockwise, so that a middle pitch is obtained with your right hand away from the antenna. This will result in a smaller total pitch range, but will also provide more space between notes. Alternatively, shifting your stance so that you are slightly closer to the pitch antenna will also cause this offset to occur. With regard to the volume control distance, you may offset the VOLUME ZERO knob by rotating it counterclockwise, so that no sound is heard until the hand is within a few inches of the antenna. By doing so, a large volume change will occur with a small hand movement, facilitating staccato passages. Smoothly flowing, legato response may be facilitated by offsetting the VOLUME ZERO knob in the clockwise direction.
As with any musical instrument, individuals will develop their own particular style for playing theremin. As a general guide, it is suggested that the hands are positioned above the antennas with vertical movement used as the primary means of changing pitch and volume. Some lateral movement of the hands is natural and can be useful in avoiding the monotony of purely vertical motion. However, the player should watch their hands to prevent them from drifting too far from the optimal sensing area. Movements of the individual fingers of the pitch hand, a technique often used by thereminists playing "pole" type instruments, may also be employed when playing the 302 Theremin, although the intervals obtained for the same movements will differ for the two types of instruments.
It is not uncommon for beginning thereminists to become tired from holding their hands in position for extended periods, although they usually become accustomed after several sessions. Repeated, abrupt, jerking motions should be avoided because such motions may cause stress and injury to the joints. Since some repositioning of the body while playing is inevitable, it is recommended that the player periodically check the response of the pitch, making sure that the lowest desired pitch is attained for a hand distance of about two feet. While standing is traditional, the theremin may also be played comfortably while seated. In this case, a short microphone stand should be used with the 302 Theremin.
There are many practice methods available for the thereminist. The ability to recognize the actual pitch of a note (e.g. "A" or "A#") is not required, but the ability to maintain and repeat the interval relationships between notes is important. It is recommended that the beginner start by playing along to a recorded melody while concentrating on obtaining the corresponding hand positions. In initial exercises, it is desirable to concentrate just on the pitch hand, while simply maintaining a fixed distance with the volume hand. The ability to use the volume hand to emphasize individual notes and provide the all-important dynamics of loudness will be attained intuitively once the student is comfortable with pitch control.
The rapid, cyclic motion of the pitch hand to create vibrato is a common technique. In this manner, the optimal desired pitch may be included within the extents of the vibrato range, therefore attaining the "perfect" pitch, at least momentarily. Vibrato typically spans the range of a quarter-tone to a full-tone interval and is an effective way to enhance technique. However, the ability to attain correct pitch with practically no vibrato is also a desirable skill. The same cyclic motions applied to the volume hand can also be used effectively for tremolo.
Recording your theremin sessions is an invaluable tool for improvement. After several practice sessions, it is suggested that the student play back a solo of moderate length and observe the accuracy of the pitch intervals and ability to maintain a consistent key. Improvement may also be attained by accompanying other instrumentalists. It is suggested that beginners find group opportunities without a vocalist, since the theremin may likely be used to play the vocal melody and possibly "compete" for the vocal range. One of the advantageous features of the 302 Theremin is its capability to produce bass tones, which may add a valuable element to the overall mix. While the theremin is often used for lead lines, it can also be used effectively in harmony or as backup.
The prospect for adding special effects to the 302 Theremin is limitless, but it is recommended that beginners first concentrate on playing "dry," perhaps with a small amount of reverberation added to provide presence. Reverberation also provides a small amount of persistence that some players find useful for attaining accurate intervals. While, historically, the theremin has been used to provide non-melodic sound, as in the stereotyped use for "special effects" in film, it is also capable of providing the means for articulate, accurate melodic work, given proper attention and adequate skill.
9. Grounding and Battery-Powered Amplifier Operation <back to contents>
A proper earth ground is essential for the 302 Theremin to operate predictably and provide the benefits of its full pitch and volume sensing distances. In mains-powered installations, the theremin receives its ground through the audio instrument cable that connects the theremin to the amplifier/speaker or mixing console.
Battery-powered amplifier/speakers do not provide the convenience of such a direct ground connection. However, the proper configuration of the audio instrument cable that connects the theremin to the amplifier/speaker can readily provide an adequate substitute. To achieve this, it is recommended that the cable, such as the recommended 15-foot Whirlwind® model number SN15, be laid in an approximate circular pattern immediately around the feet of the theremin stand and the player. Spread the cable out in a small area immediately in the vicinity of the stand to ensure that there is adequate capacitive coupling, and therefore grounding of the theremin, to the surface shared by the player and the instrument. The exact lay of the cable is not critical, but it is important not to "bundle up" the excess cable in one spot.
Note that specific adjustment to the VOLUME ZERO and PITCH ZERO knobs must be made each time the theremin is relocated. Part of these adjustments address differences in the effectiveness of the grounding in different locations. For example, the optimal settings of the ZERO knobs will change by several degrees for a 302 played in a steel-frame and concrete building, compared to one played through a battery-powered portable amplifier/speaker on a wood stage situated on a dry, sandy terrain.
Although many battery-powered amplifier/speakers provide multiple instrument and mic inputs, it is important that one is specifically dedicated to the theremin alone. This is because the variations in ground coupling from other inputs, for example, a guitar that is being moved while played, will affect the pitch and volume of the theremin.
|Do not place cables connected to this product in areas where they can cause a trip hazard.|
10. Tone Knob <back to contents>
The TONE knob on the 302 Theremin provides a wide variety of sound qualities. When fully counterclockwise, the theremin's tone will be sine wave-like, mostly devoid of harmonics. The fully clockwise setting of the TONE knob will produce a wave similar in qualities to a full-wave rectified sine wave, which is harmonically rich. Between these two extremes, a variety of tone qualities are available, including some that are similar to many other types of theremins.
CAUTION: Low-pitched tones, especially sine waves, do not seem loud, but they may produce sufficient power to cause damage to amplifiers and loudspeakers. When setting up the theremin, always start with your amplifier/speaker system volume knob settings at low levels to prevent damage. It may be desirable to use an equalizer and/or limiter at the theremin's output to match the performance of your audio system.
NOTE: The degree of pitch accuracy attained by any particular thereminist, actual or perceived, may vary depending on the tone of the theremin. In some instances where a high-level accompaniment or high ambient noise is present, the player may elect to adjust the tone for a more sine-like quality so that most of the sound energy is in the fundamental region, therefore making it easier to attain the correct pitch. Many other factors also contribute to what tone may be most appropriate; for example, a sine-like tone, dissimilar to the sounds produced by most conventional instruments, may "stand out" too much in a mix, creating a sense of incompatibility with other instruments.
11. Model 302 Theremin Specifications <back to contents>
|Useful pitch range||Five octaves (55 Hertz to 1760 Hertz)|
|Available pitch range||Seven octaves (27 Hertz to 3520 Hertz)|
|Nominal pitch sensing distance||18 inches
|Pitch response||Frequency increases as hand distance decreases|
|Tone waveform characteristic range||Sine-like wave to fully-rectified sine-like wave|
|Volume dynamic range||47dB minimum|
|Nominal volume sensing distance||14 inches
|Volume response||Volume increases as hand distance decreases|
|Control compliment||Volume Zero knob
LED Power / Battery-Good Indicator
Pitch Zero knob
|Output connector||1/4" Mono Phone Jack for standard audio instrument cable|
|Output impedance||Approximately 900 Ohms|
|Maximum output level||5 Volts Peak-to-Peak (+7dBu)|
|Power source||One IEC 6LR61 9V Alkaline Battery,
Duracell® MN1604 or equal
|Battery life||24 hours, minimum|
|Operating temperature range||40°F to 100°F|
|Storage temperature range||-10°F to 120°F|
|Overall dimensions (without antennas):||8 3/8" L x 5 1/16" W x 3 1/2" H
21.27 cm L x 12.86 cm W x 8.89 cm H
|Overall dimensions (with antennas):||26" L x 5 1/16" W x 3 1/2" H
66 cm L x 12.86 cm W x 8.89 cm H
|Antenna sensing area||8" L x 5.5" W
20.3 cm L x 14 cm W
|Weight||Approximately 2 Pounds
|Shipping weight||Approximately 3 Pounds
12. Troubleshooting Guide <back to contents>
|The LED does not illuminate when the Off/On-Level Knob is turned clockwise.||The battery is dead or weak.||Replace the battery.
(Refer to Section 6, "Battery Installation.")
|The battery connector is not making proper contact.||Examine the terminals on both the battery and the battery connector and gently reshape both female terminals by slightly squeezing their edges together.|
|There is no sound from the speaker.||The LEVEL knob on the theremin is set too low.||Turn the theremin LEVEL knob clockwise.|
|The volume control on the external amplifier or external sound system is set too low and/or an input selector switch is set incorrectly.||Increase the volume and/or gain of the external amplifier or sound
check relevant selector switch positions.
|The audio instrument cable connecting the theremin to the external equipment is defective.||Replace the cable with a known-good one.|
|The sound is distorted.||The LEVEL knob on the theremin is set too high for the external amplifier or sound system.||Reduce the theremin output by turning the LEVEL knob counterclockwise until the sound is undistorted.|
|The gain and/or volume control on the external amplifier or external sound system is set too high.||Reduce the gain and/or volume of the external sound system.|
|A decrease, instead of increase of pitch occurs as the hand is brought closer to the pitch antenna.||The PITCH ZERO knob is not adjusted properly.||Turn the theremin ZERO knobs clockwise until the desired response is obtained.|
|The pitch scale is constrained within too short a range of hand positions. For example, the lowest pitch occurs when the hand is 5 inches away from the antenna.|
|The volume range is constrained within too short a range of hand positions. For example, the volume range begins when the hand is 5 inches away from the antenna.||The VOLUME ZERO knob is not adjusted properly.|
|The note positions change while the theremin is played.||There are variations in your body position.||Hold your body at a consistent distance from the theremin, and only move your hands up and down above the antennas.|
|Objects are being moved in the proximity of the theremin.||Eliminate moving personnel and objects within a four-foot proximity of the theremin, or move the theremin to a less-trafficked area.|
|There is a persistent "fluttering" of the pitch of the tone and/or the volume level.||There is interference from a nearby electronic device and/or another
Some audio electronic products, including many "effects pedals," use a type of AC wall adapter capable of producing interference.
|Move the theremin to a different area.
Selectively unplug each effect device wall adapter from the AC outlet and note if the problem is resolved. Note: In many cases, newer-type adapters that create interference may be substituted with the older types that do not cause interference.
|When used with a battery-powered amplifier/speaker, the PITCH ZERO knob can not be adjusted adequately to obtain a useful scale; the scale is constrained within too short a range of hand positions even when the PITCH ZERO knob is fully clockwise.||There is inadequate ground coupling to the theremin.||Refer to Section 9, "Grounding and Portable Operation."|
|When used with a battery-powered amplifier/speaker, the VOLUME ZERO knob can not be adjusted adequately to obtain a range; the volume range is constrained within too short a range of hand positions even when the VOLUME ZERO knob is fully clockwise.|
|A pitch change occurs when the volume hand is moved, even when the pitch hand is held steady.|
|When used with a battery-powered amplifier/speaker, there are abrupt, small pitch shifts without hand movement.||The theremin is not tightly coupled to the stand.||Ensure that the theremin's mounting coupler is securely threaded onto the stand.|
13. Model 302 Theremin Warranty and Repair Service <back to contents>
Harrison Instruments Two-Year Limited Warranty
Harrison Instruments Corporation ("Harrison Instruments") warrants this product to be free from defects in materials and workmanship for a period of two (2) years from date of purchase, PROVIDED, however, that this limited warranty is extended only to the original purchaser and is subject to the following conditions, exclusions and limitations hereinafter set forth:
This limited warranty shall be void and of no effect, if:
In the event of a defect in materials or workmanship covered by this limited warranty, Harrison Instruments will repair the defect in materials or workmanship without charge or replace the product, at Harrison Instruments' option, provided however, that in any case, all costs of shipping for the purpose of shipping the product to Harrison Instruments for repair are paid by you, the purchaser.
THE WARRANTY REGISTRATION CARD SHOULD BE ACCURATELY COMPLETED AND MAILED TO AND RECEIVED BY HARRISON INSTRUMENTS WITHIN FOURTEEN (14) DAYS FROM THE DATE YOU RECEIVE THE PRODUCT.
In order to obtain service under this warranty, you must:
If the defect can be remedied under this limited warranty and other terms and conditions expressed herein have been complied with, Harrison Instruments will provide the necessary warranty service to repair or replace the product and will return it to you, the purchaser.
Limitation of Liability
Harrison Instruments' liability to the purchaser from any cause whatsoever and regardless of the form of action, including negligence, is limited to the the amount of the original purchase price of the product that caused the damage or that is the subject of, or directly related to, the cause of action.
Harrison Instruments does not assume liability for personal injury or
property damage arising out of, or caused by, any or all alterations or
attachments to its products, nor does Harrison Instruments assume any
responsibility for damage to interconnected non-Harrison Instruments products
that may result from the normal functioning and maintenance of Harrison
UNDER NO CIRCUMSTANCES WILL HARRISON INSTRUMENTS BE LIABLE FOR ANY LOST PROFITS, LOST SAVINGS OR COLLATERAL, ANY INCIDENTAL DAMAGES, OR ANY CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE ITS PRODUCTS, EVEN IF HARRISON INSTRUMENTS HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
THIS LIMITED WARRANTY IS IN LIEU OF ANY AND ALL WARRANTIES, EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR USE.
14. Contacting Harrison Instruments <back to contents>
Contact Harrison Instruments by e-mail at
or in writing at:
PO BOX 9012
SILVER SPRING MD 20906
(Back to 302 Theremin product description page)
Publication Number 302UM-1
Rev. 3 2018 FEB 2