Easy theremin

This instructable is to build a one antena theremin (no optical unit) , battery powered; which coincidentaly has a fair resemblance to a green pig from the "Angry birds" videogame. A theremin is an electronic instrument that poduces sound waves without physicaly touching it. I wanted to build it for friend and it seemed an easy electronic project.
I got the schematics from this web page (in spanish, but the pictures are easy to read)

http://www.pisotones.com/Theremin/Theremini.htm

A small caveat, the resistor marked as 1.07 kOhms is a mistake. Its real value is 1.7 kOhms.

Step 1 B.O.M.

I used the following materials

1 x potentiometer 5K linear
1 x potentiometer 100K linear

------ceramic capacitors--------------

2 x 27 pf
3 x 15 pf
4 x 100 nf
2 x 4,7 nf
3 x 10 nf
2 x 68 pf


------1/4 W resistances------------

2 x 470 Ohm
2 x 100 kOhm
2 x 22 kOhm
2 x 4,1k or 3,9 k
1 x 3,3 megaOhm
2 x 1 megaOhm
1 x 47 kOhm
1 x 1,7 kOhm

-------transistors-----------------------

2 x BC546
1 x BC558 (or BC557)

------chokes------------

2 x 100 microhenrys

--------miscellaneous-------------------

1 - telescopic antenna
1 x 9-volt battery holder (recycled from a dead 9-volts battery)
1 x plastics casing (recycled from a Sogo orange juicer )
1 x On/off switch (I got mine from a scavenged computer)
1 x perfboard
1 x audio jack connector
1 x solder
1 x soldering iron
1 x shielded wire (less than 50 cms)

Comments

[Moustache_Bash]

The stripboard layout, is that the component side or the soldered side?

[XLY]

It is the bird-eye point of view, or , in your words, the component side. The soldered side are only tin points as the copper strips act as traces.

[lewsidius]

which one gets the 5k and which gets the 100k in terms of pots
volume and tone

[XLY]

Tone uses the 5k lineal and Volume the 100k lineal. Answering to the following the place of the switch is non relevant as far as it opens and closes the main circuit. I placed mine in the ground connection because I think it is of common use in electronic engineering. This would be in the diagram in the lower left corner, the line comming from the line "e" to ground.

[lewsidius]

oh and where does the switch go?

[sholtob]

i was wondering what the components labelled 27p and 15p, what does the p stand for?

[XLY]

It is the abbreviation of pico (farads). The units to measure electrical capacity is the Farad. One picoFarad is 10^(-12) Farads.

[sholtob]

thanks

[blinkyblinky]

Here's the text:

Theremini


Theremini

Theremini
An article by FMK.
Introduction

I very early on a Sunday stroll on the trail of Madrid, I do not know why but I look at a simple gray plastic box unnoticed (it will be seen by the inertia of RETEX boxes and all) lying around in a post . I turn a bit and see a black rotulito which read:
T H E R E M I N

At the same time I planted a smile from ear to ear. The guy I asked for her $ 2. Of course I did not think that I ran to house to try it, I put a socket for battery did not have, I put a cool antenna that was missing and the first begins to sound great, who knows how many years after rular by there as a piece of scrap.
[Old Theremin]
This is what I found.
Click on the picture to face him.

I have spent almost 2 months looking at all the schemes of the web (in addition to those already knew) and still do not know any schema components or identical design, which seems even more original and unique. It's very simple in how simple it can be a theremin, of course. I decided to make a copy and post here the results. It was repeating the design but with modern components to make sure it would work, since I bought at the flea market and we had some components that are no longer manufactured.

This means that now I have two of these gadgets, one vintage and another say today. I made the circuit (scheme) in nice, built and ready to make it known here. The name I gave the device was THEREMINi but as I saw later, there is a so called soft so I changed THEREMINiatura. We leave it to THEREMINi for short.

Theremin is a single antenna. Thereministes "classics" are two: one for volume and one for the note. This has only been the last, it'll handle the volume of a potentiometer. It also carries a tone adjustment knob ... is to "tune" the Theremin.
The Circuit

Here in the original drawing of the layout:


[Circuit]
Theremini Circuit.
Click on the picture to see more detail.

[Image 3D]
Here is a 3D representation of the final circuit.
Click on an image to view full size.

Here you can see the theoretical scheme courtesy of friend "psst." At the end of this page you can see photos of beautiful Theremini 3 has been done.

As you can see is made, as the original, pre-punched in three plates type "veroboard." It's simple to build but you must bear in mind the following.

Assemble all the components do not have felled so that we do terminal antenna. The terminals should be as short as possible

I recommend putting a telescoping antenna and current vulgar, at least at the beginning or in the performance testing and / or boot, because the length of the adjustment also affects at least the distance that we will play.

The most important thing is to get a tone. If this does not appear for the first time the circuit is good, moved the antenna in both directions, check that the battery is in the final remedy conditions as varied little by little the value of the capacitor that goes directly to the antenna (or also of value of 86 peaks (pF) which is next to the crash LHS circuit.)

It is also important that the capacitor of the antenna to go directly to it, without using cable because if it would do the same cable and antenna and with the addition of the telescopic antenna we could go the range of adjustment.

It occurred to me to put a switch and a red LED with a resistor directly to the battery, but the diode does not work and I recommend at least in this way. Do not know why but it makes me miss the tone circuit completely and does not work, I guess that will affect the circuit somehow.

The two wires going to the tone pot (or adjust) must be of type coaxial audio (to isolate the noise).

The left circuit (at least and in full) must be isolated from interference either in a metal box for this purpose or in a homemade way as in the original that was first protected with tape (to prevent contact) and then wrapped of silver. In any case, the screen must be connected to ground through a wire coming from the housing of the pots. This is to prevent noise, hum and feedback.

If we are to switch On / Off we put a resistor between the paw 1MegaOhmio right of the capacitor is in the same output jack (see diagram) and mass as a "Pull Down Resistor" to avoid the annoying noise or clicking that occurs when you activate the switch.

You could also try to put external power (9 volts) but I have not tried it yet. The power transformer should be removed from the box.

Very important: The box should be mandatory plastic. If metal does not work properly.

As you can see is only logical precautions.

Of course with the trim pot ("Tune" or whatever you want to call it) and the antenna size can adjust the device that is not playing so you can always start with silence at a given distance from the antenna.

By being quiet if we are approaching the hand begins with a very fat and serious tone, like a synth bass or aircraft or the like and as we get closer to the antenna becomes more acute, almost to disappear when we are almost touching the antenna. By having a single antenna can not regulate the volume rather than with the potentiometer for this purpose.

The sound is very fat indeed, that is a full round sound in my opinion, and confirmaréis me. It sounds like some of those monstrous old synths.

Another thing is getting to make music with him. I think they touch the violin will be advantaged in the latter it hit tune or a scale in the air is very difficult. As a source of special effects is a mine, you can reach out and touch their feet and shoes and all, with the nose and I do not imagine the kind of things ...

I've built with current ceramic capacitors closer to the original, but maybe could get better quality sound or polyester with high quality or as SPRAGUE or similar. On this there would be plenty to talk about.

It has 3 transistors, silicon normalitos, 2 PNP and an NPN. I have to try to see how it works with germanium transistors. Now I will tell you.

As an effect based on phenomena of "capacitance" and other nearby heck should pay careful positioning of the components together. Experiment with different positions. In fact, and by accident there was a curious effect of "double sign". I was partly to put the components as well as vertically, closer together than the original. In particular see the components that cause this are 470 ohm resistor and capacitor 68picos. All close together and / or fixed inductance (shock) in ways that show in red and blue boxes in the following image in both circuits (left and right) if you do mount vertically.

Interactivity
Operating

The output jack is "line level" so that you will have to be plugged into an amp, but there is a curious trick to spare you this step if you want. Being based on high-frequency oscillators, this oscillation can be picked up by radio unreceptor. This will have to put it near an AM radio and look at the dial to tune the frequency of oscillation of the Theremin. The fact is that great and is tuned by acting on the antenna as well we can hear on the radio. Curious ... Eh?.
Sounding

Original Theremin. 651kb
Original Theremin with Delay. 1.295KB
New Theremin. 1.074KB
New Theremin with Delay. 1.371KB

Examples of the new contain the "second note" we have before.
Imagery

To not increase the load time of this page links you step as the following photos:

Old Theremin:
Interior view of old Theremin.
Detail of old Theremin circuit.
Detail of old Theremin circuit.
Detail of old Theremin circuit.
Theremini New:
Top view of the Theremin again.
Top view of the Theremin again.
Top view of the Theremin again.
Details of the Theremin pots and switch again.
Interior view of the Theremin again.
Interior view of the Theremin again.
Detail Theremin circuit again.
Detail Theremin circuit again.
Detail Theremin circuit again.

Pre-punched plate

Alvar Sanchez's friend sent us this collaboration:
Leo Theremin
Links

Theremin Tech Forum.
Tube Theremin.
Theremin World.
My Theremin.
Art's Theremin page.
Big Briar's Theremins (Bob Moog).
My Theremin: Ocabeto page in Spanish ..

Leo Theremin
Okay, very nice, but ... What is a Theremin?
For cramps.

NOTE: What follows is a blatant account is a translation of what is said on page Theremin World.

The Theremin, a little history:

The Theremin was invented in 1919 by a Russian physicist named Lev Termen who later changed to Leon Theremin. Today, his marvelous instrument is once again at the forefront of music.

In addition to not look like any other instrument, the theremin is unique because it "played without being touched." Leaving him two antennas, one controlling the note and the other volume. When a hand approaches the vertical antenna, the note rate rises (highest). When the other hand makes it to the horizontal, which is the volume decreases (or increases, depending on Theremin). Since there is no physical contact with the instrument, the performance of music requires practice and skill.

In early 1920, Leon Theremin came to the United States to spread his invention. Got a job in a music studio and trained musicians with the intention of opening the Theremin to the public. In 1938 he was deported to the Soviet Union against their will, leaving behind his studio, friends, business and his wife. After a stay in a prison camp say they worked for the KGB designing among other things, spy devices and methods of noise cancellation in audio.

Theremin was invented originally to replace entire orchestras with his "music of the ether." Although it really never happened, his music has been recorded often during all these years. In the '60s and '70s, bands like "Lothar and the Hand People," "The Bonzo Dog Doo Dah Band" and "Led Zeppelin" rescued the Theremin to the public for a short period of time. Since then sank back into a dark period until its recent resurrection in the '90s. Today, many bands use Theremins though few that use it "musically."

The haunting sound of the Theremin was used in many soundtracks for films during the '50s and '60s. It provided background music to many sci-fi classic films as "The Day the Earth", "War of the Worlds" or thrillers like "Remember".

In 1993, Steven M. Martin produced a documentary "Theremin: An Electronic Odyssey." This incredible movie shows us an insight into the history of the instrument and its inventor. The documentary includes footage and interviews with music industry legends such as Robert Moog, Todd Rundgren and Brian Wilson, as well as Professor Leon Theremin himself.

One of the original disciples of Professor Theremin was a Russian music prodigious named Clara Rockmore. At 5 years old Clara was a gifted violinist and but a physical problem with his hands forced him to abandon the violin towards the Theremin. Clara became the best "Thereministes" the world, developing a unique technique of "aerial fingering" that allowed him to play the Theremin with unparalleled precision. It can be heard on the album: "The Art of the Theremin", accompanied on piano by his sister Nadia Reisemberg.

In the late twenties, was about 500 RCA theremins, manufactured by General Electric and Westinghouse. It is estimated that today there are only half of them. It is making an effort to find the tracks of them all.

The musical pioneer Robert Moog and Theremins built long before making his famous synthesizers. The models produced the 60 "Vanguard", wedge, and the "Moog Melodia", shaped like a shoebox. Today, his company Big Briar produced the famous and popular "Etherwave" (also in kit) and the more complex "Ethervox MIDI." Also popular today are kit models "Theremax" and "Wavefront" Paia.

.. and this is just the beginning.
Demystifying a myth
For cramps.

I take this opportunity gives me the friend FMK to scuttle a widespread myth:

In "Good Vibrations" by the Beach Boys !!!.... There is NO Theremin

This is a Tannerin, which is similar but not the same or less. Antennas and do not have to "touch".

Hala!, And I be still jijiji

Here are some pictures of that has become the colleague "psst"

Photo 1.
Photo 2.
Photo 3.

THERE_e_NANO

FMK proposes a simple design even more of a Theremin. Many fewer components and even have an antenna. You can see it in its own website: THERE_e_NANO.

For any questions on these projects, get in touch with FMK in "[e-mail]."

For more information: Theremin guitarristas.org forum. Kilroy Was Here
© FMK with a little help from cramps.

Tones Ltd. Floor Cramps and Ruben Hernandez | Forum Guitarramanía

[mikeasaurus]

Neat! A video of you playing it would be awesome!

[blinkyblinky]

Do you have a schematic?