TechStuff Classic: How Theremins Work

two thousand eleven. This is how Thereman's work, and I thought it was appropriate because we're coming up on Halloween and I always think of theremans as being sort of a halloween ish kind of musical instrument because it makes that why noise. You'll hear a lot of me doing that, and also Chris Palette, my co host when we recorded this episode. So enjoy because this is one of those crazy invent chins. I can't believe someone thought of it.

It involves electro magnetism and lots of careful movements. It is very easy to make noise on a theramin. It is much harder to make music on one. And I got to see someone make wonderful music on it just the other day. So I hope you guys enjoy this episode, and I'll talk to you again in a moment. First, let's get into why we're going to do this episode. This comes to us courtesy of a Google Plus suggestion.

This suggestion comes to us from Mary who and I'm going to truncate her message a bit because she actually had quite a long with lots of different suggestions, but starts off with you may be interested to know. I, for one, am not tech savvy, at least compared to the crowd of early adopter types here on Google Plus. I'm a rhetoric major, should have graduated when I was twenty, but in one class short of might be a for financial slash academic red tape reasons with miners in French

and German guten tag Mary. Aside from being a pro vocalist, my real job is teaching English to disadvantaged and academically struggling eighth graders, which is amazing. I also tad college level rhett comp to and have private students tutoring clients, mostly college students, some high school, a few middle school primarily seeing me for writing instruction or literary interpretation analysis and historical analysis with embosses on reading comprehension. Apparently I

need to take that at any rate. Mary then goes on to give several suggestions, the last of which is finally, more music stuff for those of us who missed the B side, r I P programs like able to end pro tools, HD electronics like d being Thereman, and the very awesome react table you can see on YouTube worthy of its own podcast. While all of that is true, we are going to do a Thereman podcast. And I

know that stuff from the Beast. I did one as well, but we're really going to dive down and talk about with Thereman. It's his story how it works, uh, and you know the what's the basis behind? It's pretty interesting stuff. And as I said, the song I quoted at the beginning actually does feature a Thereman. Oh so and and uh. Just to help people who want to learn more about some of the stuff we're talking about today on how

stuff works. We don't have how Thereman's work yet, although I do believe it's actually gone out as an assignment. We do have how amplifiers work, and that's going to be a very important part of our conversation. At some point. We do have an article on the Thereman However, yes, we do have articles on the Thereman, just not one that specifically breaks down how it works. Yet, like I said, I think by the time this podcast goes live, we

may that may have changed. But I know that there is an assignment out there somewhere, floating out in the ether. It's not me. I'm not the one writing it so or at least it hasn't been assigned to me. So let's let's start talking about the history here. You wanted to UH talk about our buddy Leo Leon Thereman, actually Lev Sergeyevitch Terman, who was a scientist and inventor. UM. I got a little information about Mr Thereman from Britannica,

always a good source for the biographical on these inventors. Um. He lived in UH in St. Petersburg and uh Florida, Russia. He was well, he was born there in and died in Moscow, Florida, No, North Dakota in nine three. I

wonder if there is a Moscow not anyway. UM. So yeah, it's funny that you would say out of the ether because the original name for this device was the ether a phone, but it was later renamed to be the Thereman, and UH basically it's it's known for the way you play it, unlike pretty much every other kind of instrument I can think of where you actually need to touch it to do this. The thereman, you specifically do not touch UM. I knew a lot of people who have

that same policy. But yes, no, you're you're absolutely correct. Derriman has played without touching it. Yep. And he actually played it for for Lenin in nineteen twenty two and and for Albert Einstein in UM patented the instrument in in New York in UM, and then he went into a lot of other stuff. He UH tried to work on other musical instruments and UH worked on an electronic security system for prisons. UM ended up in a Siberian labor camp in the Soviet Union. Yeah, it's uh. He was.

He did work did some work for a in a military lab during World War Two where he was working on UH naval tracking systems and remote controls UM and even on spy technology and eavesdropping device for the KGB. UH. He got the Stalin Prize for that. UM. Smart guy is what we're talking about here. Yeah. Yeah. He became a professor of acoustics at the Moscow conservat tory Um and uh, you know, had done a lot of a lot of different kinds of electronics work. So certainly Um

a very interesting person. But you know, I think he's probably best known. I don't think anyone would argue that he's best known for the ether a phone, I mean the Thereman. Yes, since it does, since it does actually bear his name, or at least the Western version of his name. And before we go any further, I think it might might behoove us to to have a little a little listen to to what a thereman sounds like.

So this is the sound of the Theoreman. Now, listeners may have recognized that from various songs, and really I think, I think what that always reminds me of as all all those like nineteen fifties science fiction films and TV series that either used a theoreman or use some sort of other effect to create a theoreman like sound as part of the sound track. Because not everything that that

sounds like a theremin is in fact a thereman. In fact, one of the most famous songs that people tend to say had a thereman and it did not is Good Vibrations by the Beach Boys, almost said beast boys, this is that's for you yet, I haven't had enough coffee. Is good vibrations by the Beastie Boys and that would have been hilarious and wrong. But anyway, yeah, that's not that's not a thereman used in that song. It's a

it's a totally different instrument. Actually, it's called tannerin although I mean it does it does have a similar sound to it, but you actually do play that by touching. Yes, you slide your finger on it, and depending on where you're touching it, it it you know, produces a different sound. And if you were to look at a theorem and you would immediately see that the I guess the most notable feature is that it's you know, depending upon the design of it, it's gonna look like some sort of

a box. But from that box, you're gonna see a pair of antenna and one traditionally, one antenna is vertical aligned to the box, so it's it's up and down, and then a second antenna seems tends to come out the side of the box. It's horizontal and it's in a loop. And using your hands moving them close to and further away those antenna that's what controls the sound

that comes out of the theoreman. Yeah. You you know, it's always good to adjusted a little bit to the left, you know, get the get the picture just right right. Oh wait, I'm sorry, I was thinking of a different kind of antenna. Yeah, no, it's yeah, it's not a rabbit ears. Um. Yeah. In fact, that's a good point. We should mention that this is these antenna are not designed to pick up any sort of radio frequency. That's

not the purpose of the antenna. We'll get into that when we start getting into the actual uh ways that the the theoreman works. So do you said you wanted to talk a little bit at one point about songs that you may have heard or perhaps even other ways that you may have heard a thereman. Well, yeah, I mean I wasn't really a subscriber to XM Radio, the satellite radio service here in the United States, and they used to have a channel called Special X where they

would play all kinds of strange and unusual things. And they actually had, believe it or not, a whole show devoted to music from the Theoreman. And so they were all these and again, you're right, period records from like the fifties and stuff where there were uh, you know thereman songs that they were playing entire pieces on the theorem and and actually you could find a lot of

the stuff on on YouTube. I've seen people I've seen theremin orchestras, wow, where there are different people playing songs and they have different parts. So everybody's got a different purpose of doing it. And it's it sounds kind of random when you just hear the sections and segments and other songs and pop songs and things like that. But you you know, people you can actually play this as a musical instrument. And so I've I've heard a lot of that kind of stuff. Uh, I'm trying to think

of something specific. Do you have a favorite thereman song other than the one that you quoted before, other than the one I quoted before and not really, um, but there are other songs that have used it. They're actually uh, like I said, it's for me. The thing that I think about are all those those like The Day the Earth Stood Still? That would be a famous film that

used a theoreman as a sound effect. Uh. There there was a theremin used at least in some versions of the theme to Star Trek, although most of the time that was actually a vocalist who did that effect. But I believe in in one or two versions of that you can hear a thereman being used. Um So, I mean that there are bands that experiment and they'll throw that in the mix, and it may even be that it's it's a minor part of the song where you know, it's not meant to take the forefront of the melody

or anything like that. It's just another another layer of complexity within a song itself. Chris and I have more to say about how thereman's work in just a second, but let's take a quick break to thank our sponsor. So I guess we can now talk about what a theoreman does, like how does it make that sound? Like? Why is it that when you put your hand closer to or further away from, one antenna changes the pitch

and the other one controls the volume. That's by the way, the vertical one is the pitch antenna and the horizontal one is the volume antenna. Awesome, Actually it's uh it's funny because uh, typically you think of making music with an instrument as you wanted to sound as clear as possible.

Um And in the opportunity to play a thereman, you'll realize that uh uh, it's actually all about creating interference because these uh, these antennae um actually have an electromagnetic field that and you're interfering with that by coming closer and moving farther away to different degrees. So really what's what you're hearing is the sound of the interference with the machine. Yeah, it's actually to to dive down into this.

The way this works is that you've got coils of wire inside the theorem and that are generating electromagnetic field and that is propagated along the antenna. And so with the case of the pitch antenna, you have two different um uh like two different oscillators creating this electromagnetic field. One of them is a steady frequency, the other one's variable frequency, and the variable frequency all depends upon your hand coming into contact with or not contact but coming

closer or are moving further away from the pitch antenna. Uh. What will happen then is that the frequencies from these two different oscillators will mix. And this is a process that we call heterodyning. And heterodyning is you you process these these signal and you take uh. Typically you can get lots of different um um results from combining signals, but typically you look at the sum and the difference, and uh, you choose, you filter one out and you

focus on the other. And in this case we're talking about the difference because the the frequencies that are generated by these oscillators are too high for human hearing. But the difference is not um So if you are creating a variation in one frequency and the other frequency is remaining constant. Uh, when you take the difference of that and you take that signal, that signal is then within the range of human hearing. And because you've got that

one variable frequency, you can change the pitch. So and it all has to do with, of course the capacitance that we have. You know, human beings, we have a capacitance and uh, it's really most mostly based on body mass. So um. There's another interesting point is that if you have two different people playing the same theraman, they're going to quickly find out like to let let's say take one tiny little person and one huge person. So you've

got ham hands and you've got little dainty fingers. Little dainty fingers comes up there and starts playing the theraman and realizes that when they when their dainty fingers get within a certain distance of the antenna a particular pitches played. Then ham Hands comes up and starts to play, and then realizes very quickly that it's a different distance for ham hands to get to that antenna to to make that same pitch. And it has to do with the

mass of the of of ham hands. So uh, you know, it's two people playing the same theraman are going to find out that they can't mimic one another's motions and get the exact same sound. It's going to be different based upon the actual size of the musician and all. Like I said, that all has to do with the capacitance that we as humans actually have ourselves. So we interfere with that electromagnetic field the frequency combine in the heterodyning process, as I've said, As I mentioned, we filter

out the sum we take the difference of those two frequencies. Uh, and that signal is what creates the pitch. Now, even though it's within the range of human hearing, Uh, you can't really hear it very well unless you put it through an amplification process, which we'll have to talk about in a second. And the second antenna. The volume antenna really just has the one oscillator and then there's a

steady uh voltage being applied further in. And what happens is when you move your hand closer to that antenna, you are interrupting the first the signal from the first oscillator, that electromagnetic field. And as you interrupt the electromagetic magnetic field, the signal becomes weaker, which ends up being a control on the volume. So, in other words, the closer your hand gets to that second antenna, the quieter the sound

will be. You might think that, you know, you would want to get your hand closer to make the sound go up, but it's exactly the opposite. So if you put your hand close to the antenna, that sounds going to be very low. And as you take your hand away from that antenna, the horizontal antenna, the volume increases, so the pitch will remain the same, assuming that your

other hand is is steady. And and also I should mention when you watch people play the theremin, especially people who have just started to play, you might notice them moving their hands up and down the the length of the vertical antenna that really doesn't have much of an effect. It can change the pitch a little bit, but the real change in pitch has to do with the distance

from the antenna. So you can keep your hands steady at the same level respective to the vertical antenna and just change the the distance your hand is from that antenna and that would change the pitch. You don't have to move your hand up and down the length of the antenna in order to change it. Because you really need both hands to operate the well, yeah, I mean

because you have to. I mean because otherwise you would just have a steady volume time, right, So you need you need to be able to, uh, you know, have both hands free to operate the theoremans. You know, both the pitch and the volume. Um. And you know, I think it can also depend not only on the person, but on the instrument itself. No, sure, yeah you can.

You can actually tune a theoreman as well. And that that all has to do with the electronics that are inside the theoremin because depending upon the electronic components you've put in there and the the frequency difference between the variable frequency and the steady frequency. Uh, you you will have a certain octave range that that thereman is capable of playing and uh, and sometimes that octave range can

be quite uh large, very large range. But that means that you have to have even more control when you're playing it. Uh, that that tiny changes in the distance between your hand and the antenna will result in fairly significant changes in pitch, which is why the theremin is one of those instruments that's know, you can step right up and start playing it uh and have fun making weird noises, but if you want to be able to actually play a tune with with regularity, it takes a

lot of practice. It's one of those really difficult to masterpieces. And uh. I actually have a list of some of the components that are in a typical theraman if you would like to hear. Sure. Okay, so we've got the two antenna. As I mentioned before, the the volume antenna is actually a loop. It looks like a semicircle that's attached to the horizontal side one of the horizontal sides

of the theremin itself. There The reason for that design is that the old thermans were all based on vacuum tube technology, is before solid state technology was really a thing at all. The first Theraman and so um in order to be able to make this antenna and have it fit with the old system, you actually had to create this loop so as you had the right antenna length without interfering with the other electronic components of the device.

So even though we've reached a point now where most modern theramans still use vacuum tubes at least in some capacity, and we'll talk about that a little bit. Ha Hey, But Chris, I'm sure we'll have something to say about using vacuum tubes as opposed to solid state. Being the musician you would, you would know more about this than I do. But in general, it has to do with

sound quality. So there are still vacuum tubes used in most modern theramans, but they also involve some solid state electronic components now, which means that you no longer would have to do that loop um to achieve the same effect. But I think a lot of a lot of theramin designers like to use it anyway, just kind of as a throwback to the original theraman. So it's almost like it's almost like a traditional thing at this point. I hope you guys are enjoying the spooky classic episode the

Bupha Thereman's work. But though we're going to listen to a word from an advertiser. Boh. So inside the theremin, you're going to find typically a pair of chassis. One chassis is gonna be for your electromagnetic components, and this is where this is what generates that electromagnetic field for both of the antenna UM. You would normally find three oscillators in there. You would find two oscillators for the pitch,

one oscillator for the volume. UH. The this chassis often called an upper chassis, and a lot of the theramans I've looked at UH is has to be separated from the other chassis, which has the amplification and power UH elements to it, because otherwise the electromagnetic field would interfere with the operation of those elements. All right. So the lower chassis where you get the power coming into the device UH, and you have the amplification oscillators and usually

we use triodes and that you probably have heard of diodes. Diodes, of course, are those electronic components that allow electrons to pass through one way but not back yet. It's a one way lane. It allows electron UH flow in one direction. Only Triads are a little different. Triads are well, it's a kind of vacuum tube and and from a superficial level, they resemble a light bulb. And the way a triode works is that there are typically three elements within a triode,

which makes sense when you hear the name. You've got the cathode, which is the part of the triad that that will shed electrons. You've got a grid of some sort that will control the flow of electrons. It kind of acts as like a gate in a way. And then you have the anode, which is where the electrons want to get too, because it has a positive charge. Now, remember electrons have a negative charge, so negative wants to

be attracted. It is attracted to positive. So you have a positive element on one side, a negative element on the another side, and a gate in the middle to control the flow. And that's the basis behind um the triode. Now, in order to control the flow of electrons, what you have to do is you hook up that gate to a source of electricity. All right, Now, if you're generating electricity and you're you're putting a current through that gate,

that means you're putting negative electrons through the gate. Now that's going to repel the electrons coming out of the cathode. All right, so you've got the cathode. Let's imagine that the cathodes on the left hand side, and in the middle is this gate that has electrons running through it, and on the right you have the anode. Now, the the current that you're putting through that gate is going

to vary because that's your input. That's that's the signal that's going into like when you're making a sound electronically speaking into a microphone or playing a musical instrument that's plugged into this amplifier. So it's a variable frequency again, a variable current and uh and so sometimes the current is going to be is going to allow a certain number of electrons through because there's you know, you as you build up the h the charge on the cathode side,

some electrons are gonna pass through that gate. Is gonna be s long enough energy for it to go through the gate. Other times, the the signal is going to be lower, it's gonna allow more electrons through. That's the whole basis of the amplifier. So the cathode looks like a filament you have to in order to make electrons shed you have to add energy into this system. So and this is a rather than the variable source which is what we see in the gate, this is a

steady power source that's going into the cathode. So it heats up this filament which gives off light. Depending upon what kind of vacuum tube it is, it may be a different color, like a lot of them are kind of an orange ish color. If you're talking about a vacuum tube for like a big power system, it tends to burn white hot, but that's when it starts to

shed thousands and thousands of electrons. The energy from the electricity is enough to break the electrons free from their shells and then they will go toward the positively charged anode. So that is the basis. You just got a it's like a podcast within a podcast that was a basic electronics of what a triot is and what it does. We're really vacuum tubes in general, although there are other kinds of vacuum tubes besides tryouts, they're not it's not a one to one, you know. Tryout is just one

type of vacuum tube, all right. So you've got several of those in there acting as amplifiers. UM. And then you've also got your your power source, you've got your capacitors, you've got resistors UM, and then you've got the antenna. I've already spoken about those as well, and the copper

coils which generate the electromagnetic field. Those are your basic components that all together make up the guts of the thereman and there Actually, I've seen videos online that kind of give an overall view of how to build a theraman, and they're also a theramin kits out there if you want to try and make your own. UM, it's an interesting project, I understand. Like even the guy who was I was watching these videos, the guy who built olds the theorem and actually said, um, I could build them,

but I can't play them. So he said he loves he enjoys building them, and he tends to build them for other people like like bands and stuff that are interested in using the thereman. Well, um, anyone interested in in playing the thereman should check out an article that Jane mcgrathrope for the website called how to play a theoreman um and she actually quoted some of the people who are well known theoreminists thereminist dereman players. They come

from the future. It's terrible. Uh. Lydia Kavina is one. Uh. She actually studied under Leon thereman um and basically had suggested that it's good to keep your feet about a foot apart zero point three meters UM. But it really depends on the theoreman and uh, you know, and how far you want to stand away from and of course,

as you mentioned, the capacitance of the person playing it. Um. But generally depending on the number of octaves available um in that theorem, and I mean the the range of the theorem, and uh, you might have to stand farther away if it has a greater range um, according to uh um Miss Cavina Um. Also, apparently you can actually tune the device yourself by putting your right hand at your shoulder or I guess your left hand, depending on how you're playing it. So you start with your hand

at your shoulder regardless UM. And then just uh she said, the idea is you need to play the song slowly when you're getting started, because um, it takes a while to get used to uh controlling the pitch that you're trying to to make if you're actually trying to play a song and melody with it um and Uh. Clara Rockmore another person that UM Jane quoted in her article and basically said that you have to be very conscious

of what you're doing with your body. Um. You know, as a percussionist, I tend to groove a little bit, you know, start getting into it and bobbing and getting into the motion. That can affect the way you're playing, because the theremin is uh going by your body movement and how close you are to it. So anything any other stray movement is going to affect the sound coming

out of the theraman. So you have to be very careful um, and you have to be very conscious of what you're doing when you're when you're trying to play that. You know, posture and and uh, stray movements can affect it. It's a lot different from saying a guitar where you have a string that, assuming it's properly tuned, when you play that string while pressing down at a certain threat, it's always going to produce the same note, right. Uh,

there's there's no variation there. But with the thereman, it's all about the distance between and the antenna and uh and and not and and again your your body mess. So while two different people can pick up the same guitar and play the same series of notes just following the same threads, that wouldn't necessarily be the same story if they were trying to play a theramin and standing at the same distance from the device. Just pretty interesting

to me. Um. You know, I had mentioned also about the amplifiers using vacuum tubes and that that tends to be a preference. Would you like to to weigh in a little bit as a musician about that, Well, you know it, it kind of depends on the sound you're getting, you know, Um, most of the musicians and whom I rarely talk to people about using a theraman in a band, but I mean vacuum tubes and amplifiers in general, vacuum tubes.

Most of what I've heard people say is that they feel that vacuum tubes produce a warmer sound, which is the yeah, and again it's it's really in the ear of the listener. To be honest, you might say that solid state produces a flatter sound, And I mean, these are all terms that don't really have a way of It's hard to it's hard to put it in a measurable sense. But it is. It is one of those things that when you start listening to it, you say, you know what that does? It just sounds better? Yeah,

you know. And uh. And even today, a lot of amps out there for various musical instruments, not just the one, not just the amplifiers that you'll find in theirman still use vacuum tubes, even though the technology otherwise has almost disappeared. Solid state era. Yeah, well solid state too. I mean you turn on a solid state device amplifier whatever, um, it's going to be on a lot quicker. Yeah, it

doesn't have to warm up. Yeah, and a vacuum tube device will um and you can and you can see it too, if you have, if you could see through like I have, for example, I have a vacuum tube amplifier and a solid state amplifier. Um. You turn it on and at first the vacuu tubes, you know, look as though they are you know, they would win the devices off, and then they start to glow and you

could see that things are coming on. And you could turn on a source of sound, say you know, uh, turntable or a tune or radio tuner, and at first you won't hear anything, and as the vacuum tubes warm up, you know, the amplifier will begin to play the music because you're actually coming online, but it takes them a while. Um makes me think of the the beginning of the documentary Back to the Future. Yeahs turning on all the apps, right,

yea documentary. It's a good one. Yeah, but uh yeah, I mean it's it's funny though, because it's sort of like vinyl for a lot of musicians too, because for you know, the the vacuum tube manufacturers almost became extinct, and as time has worn on and people have said, you know what, I really like the way that that works. I like the sound that I get from vacuum tube amps. Or you know, I had this other thing that uses

vacuum tubes and I really like it. I actually have a ham and organ that uses um vacuum tubes too, and you know, without some manufacturer, you know, so these things have have stayed in production, even though solid state for a while it looked like it was going to knock it out. But yeah, and just like U, just like an incandescent light bulb, vacuum tubes will eventually burn out. They uh, I mean it's it's not going to be

super fast or anything. But that's why it's important that these industries still exist, because otherwise we would have a finite number that and once we got to the end of it, that would be it. So I guess we should be thankful for devices like the Thereman and guitar amplifiers for keeping a a what what otherwise people might say,

an absolute technology alive and kicking. I want to thank Dracula for joining my show there and introducing the second sponsor ad and probably making all of you cringe out there. Thanks a lot, Dracula. Guys. If you want to learn more about tech Stuff, I recommend you go check out our brand new web page. It's at tech stuff podcast dot com. There you're going to find the ways to contact the show. You're gonna find a bio about yours truly,

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