The Moog Etherwave Pro volume response: Not longer snappy!

Posted: 6/24/2009 7:59:56 PM

From: Eastleigh, Hampshire, U.K. ................................... Fred Mundell. ................................... Electronics Engineer. (Primarily Analogue) .. CV Synths 1974-1980 .. Theremin developer 2007 to present .. soon to be Developing / Trading as . ...................................

Joined: 12/7/2007

[i]"His name is Faber-Castell 63/83 Novo Biplex"[/i]

Oh YES! - Those were the days! Truly portable analogue computation! - I had no trouble with those computers - they gave "near enough" accurate answers .. unlike today where the results are perfect PROVIDED you do not make any errors in the numbers you enter.. It is far easier to enter wrong data with modern calculators than it was with 'yon slide rule.. And no problem with batteries or kids stealing it to use as a mobile phone in their game...
Posted: 6/29/2009 1:55:33 AM

From: Colmar, France

Joined: 12/31/2007

In the meantime I received very positive if not enthusiastic evaluations from two renowned thereminists via other channels.

Name dropping isn't my thing, but I would be glad if they could write also a few words here since they are both TW members.

Thank you in advance!
Posted: 6/29/2009 3:21:24 AM

From: Santa Rosa, California USA

Joined: 7/25/2005

I doubt that you could have been referring to me as a renowned thereminist; however I did install your modification, Thierry, and it works really wonderfully well (as I mentioned to you in an email.) The sensitivity of response, the extension into the lower decibels, makes it possible to thread together the notes with gossamer as well as to fade into and out of silence quite smoothly. It's humbling to a poor hack like myself how radically a little technological fix can improve one's playing--and one's enjoyment of it.

I put up a little youtube video of a part of a Hindemith Sonata here:

incase youi guys wanna see what I'm up to with Thierry's kind help. More soon . . .
Posted: 6/29/2009 7:29:08 AM

From: Canada

Joined: 8/1/2008

I was so frustrated with my Etherwave Pro's "snappy" volume response that I simply stopped playing it. It has been stuck in the back of a closet for about a year and a half. A week ago, I received the volume mod from Thierry and wrote him an open letter of thanks which I posted to the Levnet.

Since not everyone here subscribes to the Levnet, I thought I would cc ThereminWorld to tell everyone how wonderful I think Thierry's volume mod is.

June 23, 2009


Your volume mod for the Moog Etherwave Pro theremin (the EPVM1345 module) is everything I had hoped it would be. It is elegantly designed and easy to install. I thought I would probably have to take the whole morning to take everythin apart, install the module and put everything back together but the job was done, start to finish, in less than 15 minutes.

Just so that I could do a fair "before and after" comparison, I plugged my E'Pro in this morning and played for a while to get the feel of it before changing anything. After installing your
modification I plugged the system in again and VOILA! All those beautiful, lingering, pianissimo decrescendos that the theremin does so well were back. I could not do them consistently
with the snappy volume response that the instrument had before.

I did not install the rotary switch and, with the perfect volume response I have now, I cannot imagine why I would want anything other than what is currently afforded by placing the jumper on pin #4 (the highest setting).

My fear had been that perhaps you might have gone too far with the modification which would have given us what Clara Rockmore used to call the "molasses" effect, but you managed to produce what is, for me, the ideal volume linearity. I love the sound of the E'Pro but I had avoided playing the instrument because I felt I couldn't get the kind of results I wanted out of it.

I will most certainly start playing the E'Pro again.

Thank you so much for conceiving and building this thoroughly professional and highly sophisticated modification. It is too bad you never got a chance to meet the late Bob Moog. He would have loved you! Wherever he is, if he's looking down on all this, I'll bet he's saying, "That's good Thierry. That's DAMN good!"

Any Etherwave Pro owner who is dissatisfied with volume control response should order and install the EPVM1345 module. It will greatly enhance the instrument's capabilities. (The module
comes with an excellent, fully illustrated pdf document explaining exactly what it does and how to install it).

Thierry, thank you for spending the time coming up with this elegant and simple solution to what has been a problem for many Etherwave Pro owners since the instrument was introduced.

Posted: 6/29/2009 7:49:45 PM

From: Colmar, France

Joined: 12/31/2007

...and still one more evaluation (guess from whom):

[i]Dear Thierry,

The module arrived today. Installation was quite easy. I’d think It wouldn’t take an inexperienced person more than 20 minutes ... and maybe 10 minutes for someone that opened their Epro before. I was in and out in about 10 minutes. The playing and testing took the most time.

What you have done is quite beyond amazing. The dynamic curve for the “setting #3” is much closer to what I consider optimal response for the theremin than Bob Moog’s modification. With your module the Epro will finally have access to a full dynamic range!

I went back and forth, switching through the 2nd-4th settings and noticed substantial differences. I had to adjust the two front panel volume controls very much. My E-pro is definitely not like others. I expected it wouldn’t be so easy. I have for the most part settled on a good configuration with jumper setting #3. Your #4 setting felt a bit too slow in the initial part of the slope to facilitate staccato and accented notes. Overall it feels quite close to what I want. I think with a little more adjusting of the front panel knobs I’ll find most optimal response.

Bravo, Bravo, Bravo, Thierry! The slope of the perceived loudness curve is very smooth. For the Moog setting, (as with the mod I had previously) there is a noticeable bump in loudness in the second “zone”. This does not exist in either of your custom settings. I am very happy about that. I must say now, this module you have constructed should be a requirement for any owner of an Etherwave Pro who wishes to play sensitive music. The unmodified version simply does not compare.

Please know that not only has your work proven to be a success, but the effect it will have on our Epro’s playability will be noticed for years to come. I can tell you for sure, I am now able to do things that were not easy to achieve before. Wider dynamic range affords us so much... Phrasing that begins in the players ears as opposed to the audience’s ears, potentially achingly beautiful dynamic contrast, connective tissue between legato playing. The really good stuff can’t even be described in words. Bob and Lev would be very proud.

Thank you so very much. Talk to you soon,


Posted: 6/30/2009 10:45:46 AM

From: Santa Rosa, California USA

Joined: 7/25/2005

Here's a piece that relies on friend Thierry's improvement to turn many of the musical phrases:


It's Edward Elgar's "Romance" (written for bassoon.)

Thanks again, M. Frenkel!

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