Getting a theremin, what amp to buy?

Posted: 3/7/2012 10:25:11 PM

From: Croxley Green, Hertfordshire, UK

Joined: 10/5/2005

So you're getting a theremin. Congratulations. You're going to want to hear it.

The best advice is to take your theremin to a well stocked music shop and try out a whole bunch of amps, then buy the one you like.

Oh boy, people are going to hate you. Listening to a novice thereminist trying out amps is not so much fun. Better to wait until you have some skills, because how you play affects the way your theremin sounds. Really. Two thereminists with identical instruments sound very different to each other. 

So here's a suggestion of what to do in the meantime. Buy a good pair of headphones and a good mixer.

Good is the keyword here. You really want to hear your instrument at its very best with all its harmonics in place.

And the good news is that they will still be useful when you have got your amp.

The reason you want a mixer is so that you can listen to the theremin and your accompaniment (as well as your pitch preview if you are getting a theremin with pitch preview.)

I have a Mackie 403-VL23. It's small enough to drop into a travel bag. Every review I found said it was just as good as the big mackie studio mixers soundwise, and more than sufficiently versatile for my simple needs. It cost me £85 in the UK. I believe they are substantially cheaper on the other side of the Atlantic.

My headphones are Sennheiser HD 25-1 IIs. Again, excellent reviews, and I spotted them being used on the TV by a BBC sound recordist on location. That was the clincher. Also they prevent sound from escaping very effectively. I can have them as loud as I want (fairly loud, but not so loud as to harm my ears) and not disturb someone watching TV in the same room. They are about £100 hereabouts currently. 

I am certain there is room for improvement in the sound quality, there always is, but I'm also fairly confident that the cost/quality ratio is optimal - specifically this is about as good as it gets for less than the cost of your theremin.

Posted: 5/23/2012 10:00:35 AM

From: Croxley Green, Hertfordshire, UK

Joined: 10/5/2005

You'll also want a microphone stand if you're getting a cigar-box shaped theremin e.g. a Moog Etherwave.

The etherwave requires a 5/8" screw fitting. Some mic stands come with a smaller 3/8" screw. Adaptors are available either from your local music store or online. Amazon is convenient for this. Search for "Microphone Stand Thread Adaptor 3/8 to 5/8"

However, if you want to defer buying a nice mic stand until later and you have a camera tripod, you can use that. You will need an adaptor as the fitting on a camera is different to either of the mic fittings. Again a local camera shop or Amazon. Search for "tripod bushing".

Probably you'll need to use both adaptors as tripod bushing mostly increases the size to 3/8".

When you get a proper mic stand the camera tripod will still be useful as a portable theremin stand (they collapse smaller than any mike stand I have seen to date) and as a camera tripod. 


To complete your travel kit, a DI box will let you feed a copy of the signal from your theremin to a venue's PA system down a microphone (XLR) cable from just before it goes into your mixer and headphones. (For long cables you want to use XLR to maintain the quality of the signal.)

The one I got (on Peter Pringle's recommendation) is marked "Chord Passive DI Box with Noise Filter 173.294UK" - it is a rebadged Leem FDR60. Also sold as the QTX Sound Passive Filter 173.294. Which one you can get locally probably depends on where in the world you live.

Posted: 5/23/2012 8:19:40 PM

From: Nashville, TN, USA

Joined: 12/22/2011

Gordon is right when he says that the people in the music store may hate you when you are there to try out amps...I got around this problem by letting all of the sales personnel at Sam Ash Music (where I bought my practice amp) try to play the theremin also....And boy, oh boy did they want to...A bunch of kids in a candy store...Anyway, I settled on a Fender Blues Junior is small, all tube, and has a very nice tone (at least to my ears). 

Like Gordon, I also bought a passive DI box...I bought a Canadian made unit made by the Radial company, and I also spent some serious money on quality connector lines (Mogami gold).  I got these from Musician's Friend on line here in the US...I am using my DI box to feed the powered subwoofer I added to my rig to take advantage of the awesome extra bass response I got from my Moog Etherwave plus when I modded it with Thierry Frenkel's ESPE01 module (stands for Etherwave Standard Pitch Extension 01).  My Fender amp has a very nice tone, but starts to roll off somewhere below 100hz where the bass just starts to get exciting...Thus the need for the subwoofer...It's a lot of fun to shake the rafters...



Posted: 5/25/2012 6:11:37 AM

From: Croxley Green, Hertfordshire, UK

Joined: 10/5/2005

A couple of things that are good to know, specifically for Moog Etherwave Standard and Moog Etherwave Plus.


It is not unusual for people to lose the nut that attaches the pitch rod to the theremin, and it can be tricky to replace.

Prevent this happening by slipping a short piece of 10mm heat shrink tubing over the rod so the nut can't fall off. Then warm the tubing so that it grips tight and won't slide off. You may need to oil your rod as 10mm is a very close fit even before shrinking. Heat shrink tubing is the neatest solution but until you find some a couple of wraps of gaffer tape will do.

If you have some tubing left over, slip it over the front (from the player's point of view) of the volume loop. This will give you somewhere to rest your finger (for instance whilst turning around to adjust a setting on your amp) without the chirps that can sometimes result from touching the loop.

To remove the compression ring on the volume loop, twist it off with a pair of pliers.

If you have chosen not to take this advice and lose your pitch rod nut, you can make a temporary fix by borrowing one on the nuts from the volume loop. The electrical connection to the volume loop is in the rearmost connection (from the player's point of view again) so steal the nut nearest to the player.


The tool that comes with the etherwave is important. It is a PTAT - a Plastic Trimpot Alignment Tool (*) but if you want to call it a Little Red Flechette that's fine too. :-)

Gaffer tape it to the inside of your etherwave so that you can't lose it and so that it is there when you need it.

Hopefully your etherwave will be well tuned when you receive it, but over time the pitch tuning can drift until you can't turn the pitch knob far enough to make the pitch field the size you want it.

Mostly slow drift over time can be corrected by just adjusting L6. This is my quick and dirty method - best used before your theremin has drifted too far to be tuneable using the pitch knob.

1. Understand that every time you touch something other than L6 without expert advice, a bunny rabbit explodes.

2. Take the top off, put it upside-down on top of the enclosure and power up the theremin. Leave it a few minutes to stabilise, then turn the pitch knob so that zero beat is where you want it to be. 

3. Remove the lid, hold the PTAT as if to adjust L6, and move your hand without adjusting L6 until you have found zero beat. Probably the back of your hand with be about 5cm from the pitch rod.

4. Turn the pitch knob to where you would like it to be when it is tuned correctly. i.e. 12 o'clock.

5. Now slowly and gently adjust L6 without changing the position of your hand until you have found zero beat again.

6. If you can't find zero beat seek help.

7. Put the lid back on, still upside down, and check that zero beat is now where you want it.

8. Power down, put the lid on properly, power up, let it warm up, and check again. 

9. Breathe.



(*) It is not compulsory to sing The Plastic Trimpot Alignment Tool Song while using it, but if you want to, these are the words:

plastic trimpot alignment tool
plastic trimpot alignment tool
fix your theremin, that's so cool
when you lose it, look like a fool
plastic trimpot alignment tool

Posted: 5/25/2012 10:06:35 AM
All Souls Night

Joined: 5/22/2012

How many watts should one get to handle a theremin? Just for home practice. I have a little 100 watt stereo speakers that I use for my CD player that has a build in Amp. Can I use that for now if I get an adapter for the plug to make it a quarter inch plug?

Posted: 5/25/2012 11:02:19 AM

From: Croxley Green, Hertfordshire, UK

Joined: 10/5/2005

Your CD amp should work fine until you are ready to invest in better. Probably you'll need two adaptors - one to go from 1/4" to 1/8" and one to go from mono to stereo. 

My first amp was 15 watts. A Fender Frontman 15R - not terribly suitable for theremins - the etherwave signal is too hot for it without attenuation (it's a pro line-level output - the Burns B3 has guitar level outputs which would work with it) and the sound is skewed for guitars, but I liked it, it had a built in reverb (IMO, theremins need a bit of reverb - the sound is rather dry otherwise) and it was plenty loud enough for practice.

Now I have a 150W bi-amped SR Technology Jam 150+ (that's 120W to the woofer, 30W to the tweeter) and a 600W sub which gives a lovely clean, detailed sound with buckets of welly in the bass and which is good for a small to medium sized venues and for hearing your theremin over the top of a noisy band. My experiences of in-house PAs have been salutary if not always satisfying, so I prefer not to rely on them.

Posted: 5/26/2012 6:12:49 AM
All Souls Night

Joined: 5/22/2012

Thanks Gordon. Will use the Cd Amp for now. This Pegna is not going to be cheap. The CD amp uses a Y cord for a single plug in to the CD player. So any money I don't have to spend to get up and running will me a blessing. I may have to indulge in a mic stand for the Theremin, though.

Posted: 5/26/2012 10:48:41 AM

From: Nashville, TN, USA

Joined: 12/22/2011

Hey, Gordon...I wonder if Jason could somehow take your tuning protocol and put it on the tech page....If you would like, I will transcribe it to a Word document and resubmit it to Jason so that he can post it permanently (not just on this thread)....Of course, the inclusion of your most excellent poem would be mandatory, but I might leave the part about the exploding bunny out, lest it scare off some of the players here....

Posted: 5/26/2012 10:58:44 AM

From: Canada

Joined: 8/1/2008

I cannot emphasize strongly enough the need to put your monitor speaker roughly at head level and about three or four feet behind you in the traditional position. If you buy a single unit guitar speaker/amp this can be tricky because they are heavy and awkward and made for use on the floor. If you buy a guitar amp, what I suggest is that you remove the speaker from the cabinet, put a longer speaker wire on it, and place it on a pole or stand of some kind. 

The needs of the precision theremin player are quite different from those of FX players and experimentalists. 

Do not plug your theremin into your stereo. It needs its own, separate system that can be properly placed and adjusted for optimal hearing.

The problem with the adult learner is that they always know what is right for them. That is why they inevitably have to go down all their own dead ends and make all their own mistakes. There's nothing wrong with that, except that by the time they get it all sorted out they may well have lost interest in continuing. 

Kids, on the other hand, are blank slates and are unencumbered by the belief that they already know what's best. 

The predicament here is that the theremin, as Clara Rockmore pointed out, should never be anyone's first instrument, so virtually everybody comes with a set of their own baggage. It reminds me of very rich transatlantic passengers on the old ocean liners, boarding with mountains of trunks and boxes being heaved up the gangplank by small armies of porters - all destined for Davy Jones' Locker.

Posted: 5/26/2012 1:59:13 PM

From: Croxley Green, Hertfordshire, UK

Joined: 10/5/2005

Mollydad. I have no objection, although it has been said that you have to be brave to play the theremin, so maybe our players are not so timid.

Coalport. I agree, although I think having the speaker at head height is good for all thereminists, not just the melodic ones.

If you don't want to dismantle your brand new amp, make sure you get one with a 1 3/8" amp stand socket on the bottom so you can stand your amp on an amp stand.

(It is called a top hat fitting.)

If you also get a powered subwoofer, as mollydad and I have, check if it has a top hat socket on the top. That will enable you to replace your amp stand with a simple pole. My pole is about two foot long, which is just right unless you're very short. (Or as Mrs C (*) prefers to say, "built close to the ground for speed and agility".)


(*) My lovely wife, who does not need to stoop when conquering.

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