The Etherwave Cometh

Guitar and Bass amps have both potential problems with theremins:

a) the magnetic pickups of guitars and basses have an output voltage of about 2 to 5 mV while a theremin has almost line level, around 200 to 500mV. Thus you risk to overdrive the input stage of the guitar or bass amp which will give an unpleasant and distorted sound.

b) guitar and bass amps have no flat frequency response but they attenuate higher frequencies to compensate the inductive effects of magnetic pickups. Thus your theremin will not only sound distorted (see above) but also muffled.

That's why I always recommend using a keyboard amp, which accepts a higher input level and has a flat frequency response. The Behringer KT-108 works very well with the Etherwave and costs only around $99. Still much better are active studio monitor speakers. I use a Yamaha MSP-3 which can be mounted on a mic stand at ear height behind or besides the player and gives an excellent analytic sound. (ok, this solution is somewhat more expensive, the MSP-3 plus mic stand adapter plus mic stand is around $300, but it's worth every cent!)

Shiny, 

Try everything you have and see what you like best. REMEMBER** your ability to play the theremin with accuracy and precision will depend on how well you hear yourself. Unlike other instruments where there are visual and/or tactile references for the notes, thereminists are in the dark acoustically, and must depend entirely on sonic feedback.

As for the raw sound of a theremin, if you don't like it there are many things you can do to alter it radically. Recently you may have heard what the Electro-Harmonix TALKING MACHINE can do to the sound of a theremin (see Theremin World's front page: LOST IN THE STARS). That's just an example of what is possible. A theremin is not like a violin or a guitar or other acoustic instruments where you are pretty much stuck with the sound. 

"The theremin is an electronic instrument and is entirely at home in the electronic environment."  Robert Moog

Love that quote - thanks @coalport!

What a cool little community you all have here - all of this information is helpful and I'll use it to my advantage.  For amps I think my PA might be a good temp solution, possibly even ideal, although I do have a pair of active powered Samsung monitors that are collecting dust and might be a better solution, if I can figure out how to hook both up to the Etherwave. But knowing me I am headed toward a keyboard amp...I'm a big believer of having the purest possible match.

Hopefully I'll be able to contribute meaningfully to this site in the future as a thereminst...can't wait to start playing. will report back.

SB - What one considers to be "'best" will be different from one person to the next.  As coalport suggests, it is best to try everything you have first.  I've used guitar amps with no serious ill effects by keeping the gain and volume way down. If you can attenuate the output of the Etherwave, so much the better.  As Thierry noted, guitar amps can attenuate the high frequencies, but that is not necessarily a bad thing as it can keep the high range from becoming too screechy.  Still, with that said, PA monitors and keyboard amps are still the best bet.  A low frequency driver of at least 10 to 12 inches is probably preferred by most people.  Anything 8 inches and below will probably sound too thin and buzzy.

One thing you will definitely want to consider is an amp or set-up with some reverb.  I am currently forced to use headphones and (stereo) reverb is essential.  The dry signal is just too intense and boring.

One thing I've never really heard discussed before is the relative value of either a mono or stereo output, which would be fodder for another thread.  That may depend mostly on the type of music you are playing.  I would think that, for the player's monitor at least, mono would be preferred for hearing the pitch more clearly.  The theremin is obviously mono, but running it though a stereo effects unit and two speakers will change your perception of the sound.

I thought of that too - mono vs stereo. Using my PA monitors amassing monitors would create a stereo environment, I presume. My PA has built-in reverb and delay, which I would certainly take advantage of...the monitors would produce a dry and exacting output. But again I am not sure how I would connect those anyway, without some kind of bridge device.

For mono, my Roland cube has lots of effects but is probably too small, but my Fender tube might be an interesting option if I turn the gain down and use the reverb. I can also add more reverb through the footswitch. I am mildly concerned about the "Screech" I have seen some Etherwave users post about, so maybe the Fender eliminates that.  All fun options to test.

Definitely too small is my amp "Mighty":

If by screech you mean the chirp when you touch the antenna, you can attenuate that by wrapping a piece of electrical tape around the antenna so your finger never actually comes in contact with it.  Another form of "screech" I've noticed is some resonant frequencies in upper ranges with certain amps.  I've started running my theremin through an EQ module in Sonar XP when I play, and I can use a notch filter to kill those nasty frequencies selectively.

@Detlev - HA!  Cute!  You could make headphones from 2 of them :)

No, I didn't mean the chirp from touching the antenna.  I was referring to the piercing harshness of the uppermost range.  But, a melodic thereminist shouldn't be playing that high anyway.

Electrical tape?!!!  Spiral cable wrap does an excellent job without the sticky, gooey residue.

Everybody who finds the sound of his Etherwave too harsh in the high register may experiment with C26 which is by default 10nF (0.01uF) or sometimes even only 4.7nF (4700pF).

Try values among 15nF, 18nF, 22nF, 27nF, 33nF and be surprised of the result. The bigger the capacitance the smoother the sound. If you select a too big value, you risk a decreasing audio level with increasing frequency. The art is to find the best compromise depending on your personal preferences and the frequency response of the following audio chain.