Electronics Illustrated Magazine, January 1961

This January, 1961 issue of Electronics Illustrated magazine includes a construction article for a tube-powered Theremin. Theremins were invented in the 1920s by a Russian, Leon Theremin. While not strictly radio-related, they illustrate an important chapter in the development of electronic music and may be appealing to anyone with an interest in tube devices.

My other Theremin article has more information about the history of the Theremin, so I won't repeat that content here.

The cover shows a lissome lady playing a Theremin. Unlike all other instruments, the Theremin is played without any physical contact. You move your hands in the air near two antennas to control the pitch and volume of the Theremin's single note.

The other pages contain the complete construction article.

This design employs five tubes (12BE6, 12BE6, 12AU7, 6AN8, 6X4) with a transformer-type power supply. It is somewhat more sophisticated than the 1955 design shown in my other Theremin article.

Except for the antennas, all of the parts should be readily available from suppliers such as Antique Electronic Supply. Coils are sometimes problematic when following old construction plans. Not so in this case. The required coils are generic oscillator coils, Miller type 70-OSC, which are available from AES.

The antennas can be any large pieces of metal. This 1961 cover photo shows a futuristic loop on one side and a metal plate on the other. The 1955 construction article shows large metal letters—a V for volume and a T for tone. The original 1920s RCA Theremin used plain metal rods about two feet in length. If you build your own Theremin, you can let your imagination run riot!

The last page of this article explains the theory of operation. Simply put, the Theremin produces a tone by combining the output of two oscillators. The tone's frequency is affected by your body capacitance as you move your hand near the tone antenna. Similarly, body capacitance makes the volume louder or softer as you move your hand near the volume antenna.

While simple in theory, playing a Theremin is very difficult in practice. I have played two original RCA Theremins in different museums, and found it almost impossible to produce something resembling a simple tune. Extraordinary physical control is required to play this instrument which has no keys or frets and provides no physical feedback to the musician.

Nevertheless, they can fun to experiment with, and with practice, perhaps you can become a true Thereminist. I have heard only one Theremin in live performance, by the Minneapolis avant-garde poetry/music group known as DaDa Cha-Cha, several years ago.

If you succeed in building a Theremin from these plans, I'd love to hear about it. Feel free to send me an email with photos and any comments about your construction methods.