Big Briar Series 91b

Posted: 2/13/2009 9:57:27 PM

Joined: 2/13/2009

ello all. I was given a Big Briar series 91b U shaped theremin a few years back from a buddy. I'll never let it go and really love it but as I try to find out about this model it seems as they are rare.

I'm curious to know the value of one in good shape. I've searched ebay for the past few years and have not seen one pop up at all.

Were there limited numbers produced? Are they special? If they went for 2K back then are they worth the same, less, or more now?


Posted: 2/14/2009 3:48:23 AM


Joined: 4/14/2008

Seems like you've already posted this a couple days earlier on the Moog Forum:

link (

...and I think that's probably about the best info you're going to get on the topic.

Personally, I view the EPro as a far more desirable Bob Moog Theremin. In terms of timberal variety from it's non-traditional Filter Control, built in Tuner / Pitch Preview, Register Switching, better visual design aesthetics, and easier portability for the traveling performer-- the 91b isn't in the same class as the EPro.

The 91b is basically a replica of an older Leon design that wasn't really that popular. And as a replica, it's expensive and limited (by today's standards) in what it does as an instrument. If one wants to emulate an early RCA style machine, just get a WaveFront Classic. They're much more affordable, and far more attractive.

Perhaps die-hard collectors might be interested in the fugly 91b design, but I'm going to guess there aren't a lot of those folks around...

[i]fixed url TW-Staff[/i]
Posted: 2/14/2009 7:55:01 AM

From: Canada

Joined: 8/1/2008

It might be worth adding that, technically speaking, the SERIES 91 Big Briar theremins are not theremins at all because they do not produce sound heterodynamically. They are gesturally controlled tone generators (similar to a synthesizer and to VOICE TWO on the Etherwave theremin).

They are nevertheless fine instruments and are considered very desirable. They handle and sound like traditional theremins and I would guess that the U-shaped 91B (the same model Lydia Kavina used in her MASTERING THE THEREMIN video) is probably worth about $4000.00 tops today.

Obviously people are not scrambling for these instruments. You would have to be patient and look for the right buyer. You could always try putting it on eBay and start the bidding at around $3000.00.

Several years ago, I bought a mint condition, traditional cabinet, SERIES 91A (signed inside by Bob Moog himself) from Levnet founder Dave Ball for about $2500.00.

Posted: 2/14/2009 7:58:56 AM

From: Canada

Joined: 8/1/2008

***Sorry, my reference to the VOICE TWO on the "Etherwave" theremin in the post above, should read ETHERVOX theremin.
Posted: 2/15/2009 11:57:57 AM

From: Colmar, France

Joined: 12/31/2007

I would not over-estimate the value of a Big Briar series 91 theremin... call me heretic...

...but seen the fact that it isn't a true heterodyning theremin but something with a kind of PLL and a VCO and that it has although such a limited pitch range compared to contemporary and much cheaper instruments (my 400$ Etherwave Standard goes now up to A8 after some tuning), you have a rather outdated instrument.

It may naturally have a certain value for collectors but I think that most people will agree with me that a vintage RCA has much more charm!
Posted: 2/17/2009 12:59:52 AM

From: Boulder, Colorado

Joined: 8/17/2005

Thierry wrote: my 400$ Etherwave Standard goes now up to A8 after some tuning.
Thierry, are you saying your Etherwave plays the A above the 88th key on the piano (A8 would be 7040hz)?
7040hz (
Doesn't this compress the pitch linearity?
Posted: 2/17/2009 2:08:26 AM

From: Colmar, France

Joined: 12/31/2007

The highest 1.5 octaves are really somewhat compressed. But this range is not the one where I play normally. Out of that it is difficult to hit this A8 exactly at 1/25" distance from the antenna...

My first intention for this tuning was to shorten the "octave distance" in the middle range since I have small hands. The second thing is that I wanted to make the C6 - C7 octave (1040-2080Hz) better accessible. That means in a little more distance from the pitch rod as initially and thus in the more linear zone.

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