Theremin

The Hoge Moogs





The Hoge Bio





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There are now four theremins in the Salon, three by Bob Moog, and the newest arrival by Gene Segal of Wavefront. I feel the Moog EtherWave Pro and the Wavefront Classic theremins are the among very best theremins ever produced.


The Wavefront Classic
The Wavefront Classic
is modeled after the vintage RCA theremin with new solid state circuitry. It is a true professional concert theremin andm a beautiful in both looks and sound. Two of the features I've relied on in the EtherWave Pro, a mute switch and pitch preview, were available as add-ons. It is an extremely musical and versatile theremin with a distinct voice and the most expressive volume loop I've played. It was out of production for several years and now fills the need for a serious instrument for professional players. Both Wavefront and Moog carry on the technical and musical vision of Lev Termen.

The EtherWave Pro was an astounding musical instrument and it's a true pity it went out of production in 2007. Bob Moog refined his various designs yet again to give serious players an expressive, extremely playable and practical instrument packing many features and a beautiful sound into a stunning design.

The EtherWave Standard remains, well, the standard and is a solid and musical theremin; the most portable and popular of the Moog designs. It has been in continuous production longer than any other theremin.

All of my theremins have pitch preview added. Though fully playable, and often I do play, without pitch preview. I have come to find it valuable and a professionally responsible feature when playing in public and with other musicians.

The EtherWave Pros both also have a modification to the volume circuit which is detailed below and both also have under gone extensive adjustments of all the user accessible controls to fine tune them to my playing style and requirements. I've also put marks on the wood knobs as a visual position reference. And have darkened the light maple face and arm on both.


Wavefront Classic
[2009]

Moog EtherWave Pro
[2004 Original Edition]
[2007 Final Edition]

Moog EtherWave Standard
[2004 Cherry]


Modifications

Pitch Preview
[All]
Changes the tuner output on the EWPro, and adds a jack and a volume knob on the Standard , to be identical to the main output but without volume control.

EWStandard with preview jack and volume knob mod. by Ryan Cox, Moog Music

Volume Modification
[EtherWave Pros Only]
Smoothes out the initial attack of the sound envelope easing the “snap” which in the original volume circuit came from the circuit having a more exponential response to your linear hand-movement away from the volume antenna.
The modification uses a network of diodes and resistors to create a resistance that varies as the pitch voltage changes, in a way that makes the volume circuit response more linear with respect to your hand movement away from the antenna.

EWPwo 1 post mod-s.

Adjustments

Tiny Adjustment Coil Screws
The fine adjustment coil screws in the Wavefront Classic are easily accessible by lifting the lid, and are clearly marked. So far I have not had to adjust them.

On the Etherwave Pro-s:
Volume
The the adjusment coil screw for volume on the side under the antenna sets the distance away from the volume antenna at which complete silence is obtained. It is extremely sensitive and requires the most fractional turn. It doesn’t have very much range, but you should notice the instrument going silent a little bit closer or farther away from the loop depending on where this is set. It may also slightly reduce or increase the overall main output.
Adjusted the tiny volume screw to set to about three fingers from the loop, with a slight increase on the front panel volume response.

Pitch
The pitch adjustment screw on the underside of the arm changes the width of the “zero-beat” zone at the boundary of the pitch field. When you move back to the distance at which the pitch drops to zero and the theremin is silent, if you move farther back a certain distance the pitch will start to sound and rise again. There is a band in which the pitch remains at zero; you should be able to make this band wider or narrower with the pitch adjustment screw. Again, it probably won’t have a huge effect but that’s what it should be changing.

EWPro Front Panel Screws

Volume Response
increases the speed of the response and will also decrease the distance of the field from the antenna slightly.

Pitch Response
It basically adjusts the spacing of the lowest notes and the width of zero beat.
Adjusted it on the second instrument to expand zero beat a hair to match the first.
Matched both to the closest common output level.

Repairs

EtherWave Pro Spinning Problem
Never twist the EWPro on its stand to adjust its positioning without loosening the twist lock and adjusting the V notched tube.  The V plug is held in with glue and over time, and a few bumps, can come loose and the instrument will start to spin at the slightest touch.

To fix the spinning problem I needed to pull out the V plug and re-glue it.  This required: an eight hour drying two part epoxy, sand paper, a pocket knife, and chop sticks.  A tool bench with a vice lined with cardboard would be best when pulling out the V plug, but I had to use vice grips.

Pulled the plug out with vice grips wrapped in rag cloth to minimize denting from the grip teeth.  It was hard to pull out, and took a while.

The V plug was fairly easy to clean be sure to clear out the grooves in it.   The tube was harder to clean, I had to scrape the inside of the tube with pocket knife and sandpaper wrapped around a chop stick.

The V plug is totally loose without glue.  Apply plenty of mixed epoxy and be ready to wipe off the excess when you insert the plug back into the tube.  I let it lay on it's side to set, turning once in a while, then put back in the stand to dry and cure.

After a good long time to let it set, the instrument feels solid again and I'm being more careful not to bump it.