RCA Theremin Frequently Asked Questions

Should I replace the old capacitors in my RCA Theremin?

No, this is generally not recommended. See our thoughts on capacitors in RCA Theremins.

Can you provide information about my Moog Etherwave (or Pro, series 91, PAIA, Enkelar, etc.)?

We only deal with 1929 RCA Theremins and Vintage Lev-built or Teletouch instruments on this web site. If you have a Moog 201 or 351, however, we would be interested to hear from you and you can contact us at experts @ rcatheremin.com

How much is an RCA Theremin worth?

Based on sales results that we've been tracking for the past several years, the range is about $3,500 for a basket case needing full restoration, to about $13,000 for the best original, properly working examples.

The RCA 106 Loudspeaker ranges in price from about $200 to $500 depending on condition, not including the cost to ship.

Can you tell me what my theremin is worth?

We are not certified appraisers at this time. However our unofficial appraisals have been consistently more on target than the professional appraisals (legitimate and otherwise) that we have seen. We take far more specific factors into account than the general appraisal services do, and can provide up-to-date valuations on your RCA theremin. Contact us for more details.

A note on appraisals: We have seen seemingly inflated Certified Appraisals of RCA Theremins and RCA 106 Loudspeakers, as part of eBay auctions and other auction services from time to time. These tend to be significantly higher than the high end of the range noted above. Frankly, we don't know where they're getting their information, but it's possible that some private sales have brought higher figures than those we've been able to track.

Follow the Do's and Don'ts listed below to keep your RCA Theremin in its most valuable condition.

My RCA Theremin has no legs. Is this a rare variant? Is this stand original?

An nice original RCA Theremin on the left and poor, sad RCA Theremin with legs sawed off on the right

RCA Theremin (left) and an RCA Theremin with legs sawed off (right).

All RCA Theremins left the factory with four permanently attached legs and stand 47 inches tall (64 inches with antenna). Many RCA Theremins had their legs cut off to make them easier to transport. In some cases a table upon which to place the truncated instrument was fashioned by attaching the original legs to a small platform top.

Contact experts @ rcatheremin.com for information on new replacement legs for your RCA Theremin. Note that correct installation of legs requires some cabinet disassembly, or an alternative method for a functional replacement with fewer attachment points.

Is my RCA Theremin Missing Parts? Where can I get replacements?

There are a few parts of the RCA Theremin that are commonly lost. These include the pitch and volume antennas, the pilot lamp jewel & ring, pilot lamp extender, doors, music shelf and small metal escutcheons labeled On/Off and Play/Off that mount to the switches.

Commonly missing parts of RCA Theremins

Commonly missing parts of RCA Theremins.

Contact experts @ rcatheremin.com for current availability, cost and wait time for high-quality replicas of the above listed parts, as well as for complete reproduction RCA Theremin cabinets.

Where can I sell my RCA Theremin?

Classified ad sections appear on RCATheremin.com's Classifieds page and ThereminWorld.com. To broaden your prospective audience, you can list your theremin for sale on eBay.

Where can I find an RCA Theremin to buy?

Check the resources noted directly above. Beware of fake eBay auctions and fake Craigslist ads for RCA Theremins, both of which have been seen on occasion.

Where can I get vacuum tubes for my RCA Theremin?

We can supply tested, guaranteed vacuum tubes at reasonable prices for your RCA theremin, or you can search for vacuum tubes on eBay (buyer beware) or from antique radio parts suppliers. It has been our experience that some established dealers occasionally send out vacuum tubes that in fact have problems. Vacuum tubes that we offer are guaranteed and have been tested for function in an actual RCA Theremin, a claim that few other suppliers can make.

Where can I get my RCA Theremin repaired?

We offer experienced and conscientious repair, restoration, voicing and adjustment of RCA Theremins. We can also provide non-invasive modifications, and a simple timbre adjustment control. Contact experts @ rcatheremin.com for current pricing.

Whether buying, selling or obtaining service, to ensure the safest transit for your RCA Theremin we strongly recommend having a shipping crate made to our specifications (We have plans for sale on our Parts page). Prior to considering shipping your RCA Theremin for repairs, please take a few minutes to review the Troubleshooting Advice section.

Why do you call the power supply an SPU?

RCA's power supply designation in the late 1920s was Socket Power Unit. When the RCA Theremin came out in 1929, AC radios were only a year or two into regular production and were stated to be wired for light socket power. Many electrified homes of the era had only one outlet per room, and some rooms were wired only for a ceiling lamp. Unscrewing the light bulb from the ceiling fixture and replacing it with a Y adapter allowed the light socket to accept an Edison-base AC appliance jack, into which the appliance would be plugged, hence light socket power, or simply socket power.

On my theremin, the arrows on the control knobs (and/or "zero beat" position) are different from your picture. Why is this?

The front panel control of an RCA Theremin, highlighting the function of the pitch knob

Our control knob images depict the arrow and zero beat position as they would appear on a correctly calibrated RCA Theremin. Due to changed component values, incorrect trimmer adjustments and incorrect position of control knobs on their shafts, your theremin may be different.

Do's & Don'ts