Who has actually BUILT their own theremin here?

I built a Theremax and have made a couple of mods to it.

I like the tone of the Theremax -- it reminds me of someone humming and has a lovely treble register. The pitch antenna is difficult to play (compared to the Epro) and I like the Theremax enough that I plan to mod it with a better antenna.

The Tmax's tone is a nice complement to my Epro's tone... the Epro is definately a "foreground"... solo, instrument. The Theremax is more subdued, gentle (I did mod it somewhat). The following thread is a kind of play-by-play of my experience of troubleshooting and modding the Tmax:

http://www.thereminworld.com/forum.asp?cmd=p&T=169&F=10

I also built the PAIA Theremax. It was the first theremin I ever bought, a little over seven years ago. At the time, I was astounded because I'd known about theremins since I was 12, but never thought they were still made. It was inexpensive, so I figured, "perfect -- if it turns out I'm unable to play, I've only lost $150." Built it from the kit and it worked...BUT...not quite perfectly. I wasn't getting enough volume. Turned out that a splatter of solder so tiny you could barely see it with a magnifying glass was stuck to the circuit board across a copper pathway (now I'm showing my ignorance of electronics -- don't know what the correct name is). Once the little speck was removed, it worked beautifully, but it took over a day just to FIND it. It was my first and only electronics project. Very rewarding. In some instances, I prefer its sound to my other 3 three (more expensive) theremins. I've always wanted to replace the antennae, though, since they're such flimsy pieces of copper. After a couple of accidents on the part of my two young children, they're both a bit bent looking. I also found that while the standard Etherwave yeilded about a five and a half to six octave range, the Theremax yeilded eight once I adjusted it. I'd probably play it a lot more in public, but it doesn't really travel well. Still, for people just starting out who are unable to afford more, it's a good choice.

I had to chuckle as I read your post because I, too, had a problem with low volume. Mine didn't turn out to be a solder bridge (the term for the little spec of solder) ... rather it was a bad solder joint... took me forever to find. The solder joint had just enough conductivity to pass some of the audio signal however not enough to drive the comparator chip (that produces the square wave tone). I discovered it by accident when I pulled one of the capacitors out of the circuit and, after testing it, soldered it back in place and then it worked!

Ahh... the trials and tribulations of kitbuilding :)

I have to wonder what people would think of the Theremax if professionally pre-built versions were available and if it had better antennas. I too liked the sound of mine, but I found the Etherwave infinitely more "playable". I've met several people who demonstrated excellent theremin technique with a Theremax but found that they had difficulty playing an Etherwave. Perhaps it's just a matter of getting used to the instrument as much as the physical note spacing or linearity.

When I was experimenting and modifying my Theremax, I found that simply replacing the antennas with rod-type made a huge difference in playability. Also, it seems that what frequency you tune the pitch antenna coil to can make a difference in linearity - there is definitely a "sweet spot" on mine.

I too had a laugh with the solder-bridge incident. When I first got mine together, I had no sound for two days, only to discover that I had put one of the diodes in backwards. I was pulling my hair out trying to find a solder bridge, and didn't even bother looking at the diodes since I assumed I couldn't possibly have made that kind of mistake, since the diodes are polarity-marked. As Jason said, the perils of kit-building!

I must admit that it is very rewarding to play a theremin that you built yourself.

Just a side-note: the reason I purchased a second theremin after the Theremax was because I was hoping to find a machine with a quicker response and more possibilities for precise articulation. My Theremax had a sort of "creamy" quality to the notes --never a sharp delineation between attack and instant/clean decay. So I bought a standard Etherwave. It was like having to learn to play from scratch because it was so much more responsive. The same happened with my Etherwave Pro when it arrived. I'm still tying to find manual timbre settings that suit the music I play.

I have built two Theremins from scratch, Moog's 1954 version and a copy of a RCA Theremin. I have also restored a RCA Theremin to original new condition.

I am wondering if Moog will sell their antennas as spares. This would save one a great deal of trouble in have to fabricate them for a homebrew theremin?

Hello.
Never be faint of heart when considering to build a ThereMax kit. The documentation is awesome, the company customer service is awesome, and the Theremin World help forums are awesome. Go for it!
I have built and modified a TMax, and it plays wonderfully. What has been said in previous posts to this page is very true. The TMax has a sweet "creamy" sine wave, and has the ability to voltage control a variety of synths that will take the same.
Definately increase the volume and pitch antennea diameter. Look to the 'Kees' units and then become very familiar with the plumbing conduits and the like at your local and favorite hardware store. You should probably keep the lengths the same on the new antennae.
Good-Luck!
Dave

I scratch-built two etherwaves.