My Theremin History
My present theremins |
I've built theremins since my teenage days in the '60's, some of which were dismal failures and
others which were merely flaky. They ranged from the very simple to the un-necessarily complex,
and none have survived the onslaught of the years. The first instrument that I actually found usable was built from a Southwest Technical Products model 144 kit in the early seventies. I actually used this in performance as late as 1994, and have since turned it over to my son Michael, an accomplished propeller- head in his own right. |
| I've since acquired an original SWTP Model 142,
the predecessor to the 144 and the one that made such a splash in the electronics world with its
publication in Popular Electronics way back in 1967. This is shown in the foreground in
the photo above. The unit that I "inherited" was in rather rough shape, but I managed
to get it working as good as new... which is to say, not all that well because of its somewhat
deficient volume control circuitry, and severe instability due to the "crystal-set" -
type coils, with no fine-tuning facility. As you can see in the picture of the circuit board
below, one of these coils was missing in the unit I inherited, so until I can find one to
replace it I've substituted a much more stable (but not original) coil salvaged from an old
Pye Westminster FM 2-way radio. (Oh well, at least it's of the same vintage!)
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SWTP 142 Circuit Board |
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My pride and joy is the instrument shown below; a built-to-the-hilt "Theremax" by
PaIA Electronics. You can see the Theremax board at the
front-left corner. Notice that it's mounted upside down; this is because I prefer to have pitch
control on the left, and articulation (volume control) on the right. Perhaps that's because I'm
also a right-handed guitarist; in any case, it just seems more natural to me that way. Note also the shielding around the RF oscillators. This reduced the interaction between them, allowing even low bass notes to be stable. The circuit also incorporates other mods, including 8ba and 15ba octave injection with separate level controls (rather like organ stops), documented in the Theremax mods page. |
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Of course, no modern theremin would be complete without a
Dis*Player, which you see built into the clear plexiglas case along the far edge.
This makes it a lot easier to play in some semblance of standard tuning, since
the visual feedback helps you land on the right note... at the right time!
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| Built onto a piece of perfboard is a combination power supply and audio amplifier, built around a TDA2030 8-watt amplifier IC. A four-inch internal bottom-fired speaker (not visible) serves as a local monitor; monitoring can be either constant- level (so you can tune a certain note before bringing up the volume to the main PA) or "as played,", or off entirely, as selected with a front-panel switch. The monitor also has its own local volume control. A built-in rechargeable NiCd battery pack rounds out the stuff under the hood. |
| Another novel facility included in this super instrument is an on-board echo board. I've found that echo is the single most useful effect that can be applied to the sound of a theremin. Echo goes with theremins like... er... peanut butter goes with jelly. You see the CanaKit model 128 analog bucket-brigade echo unit in the front right of the picture above. A close-up of the assembled kit is shown to the right (though note that I've relocated the pots to the front panel). |  |
| This instrument is now owned by Jim Ubersetzig, who has dubbed it "The Crystal Theremax." Jim is himself an avid experimenter, and has an interesting site about his Polyphonic Theremin. He mentions in an email, "That web site is kindly maintained by Wilco Botermans. He was kind enough to provide information about my polyphonic theremin ( thank you Wilco ! )" |
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Yet-another crazy idea... What happens if you start to restore an old AM battery-operated tube table radio... and put it back together all wrong? The answer - BAMTRAT! (Battery AM Tube Radio Authentic Theremin). While such a project might offend the sensibilities of collectors, I decided to go ahead with it because this poor old radio had been sitting in my "to do" corner for several years, and I could never quite get the motivation to restore it. After all, the reward for all that work would have been just another AM radio. Instead, I decided to re-use all the major components to create a tube theremin with as authentic a sound as possible. A novel "differential tuning" approach makes for ease of tuning using the original tuning dial. The close-coupled antenna coil, used as the variable pitch oscillator, duplicates Lev Termen's trick of using hard coupling to provide that unique saw-like classic theremin sound. Click here for more info and pictures |
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This listing wouldn't be complete without at least a mention of my "virtual" theremins. The first is an interesting piece of software called "MouSing" in which a theremin is simulated by using the X and Y axes of your computer mouse to simulate pitch and volume antennae, respectively. It's a great way to get a taste of the sound and feel of a real theremin before buying or building one. Download a free evaluation copy from Sagebrush Software. Quite a hoot. Versions available for either Win3.x or Win9x. |
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Another "virtual" theremin is good old midi, using the GM "whistle" patch,
and lots of patience with pitch-bend and expression controllers. A sample of such labour- intensive
tomfoolery is my midi of my Impending Doom
composition. (Best played on a Yamaha XG synth or SYG SoftSynth, but should work with any
reasonable wave-table card such as SBLive!.) |
| This one is just way too much fun. You control
Professor Theremin's arms with your mouse, and he plays along with the band... which is also under
your control. Highly recommended just for the sheer joy of it... and who knows, it might even be useful!
Only the Beeb could come up with something as cute'n'goofy as the
BBC Virtual Theremin
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Keep on theremining! I will... :-)
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About Theremin Sensitivity
Theremax mods
The "Dis*Player"
Dis*Player tech article
My Theremin Music
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