Tag Archive: synthesizer

2nd TANR Prototype, workshop ready.

2nd TANR Prototype, workshop ready.

TANR is a tiny AVR based synthesizer. It is not too far from Ljudmaskin, but there are few differences. Most important is that it has more touch contacts. It has three main contacts that are chained with resistors two form additional contacts. I have also added a potentiometer that is used to change modes between different synthesis algorithms.

There are two main influences for my synth. First one is Lumenoise, an audiovisual synthesizer by Niklas Roy. Those of you who have had a chance of trying this thing, know that its synthesis algorithm is a weird mix of control and total lack of control, both at the same time. I wanted to have something that would have the same feel than Lumenoise. This is where the synthesis algorithm kicks in. I have done workshop about algorithmic music players. That workshop was based on concept of ‘one line symphonies’ by Finnish demoscene veteran Viznut.

The circuit diagram of TANR. The circuit consists of Attiny85 and lm386.

The circuit diagram of TANR. The circuit consists of Attiny85 and lm386.

The schematics of TANR show that most of the magic happens in software. How TANR works is that it is using bunch of one line symphonies, switching between them and modulating their parameters based on readings from touch contacts, number of clock cycles etc. I think there is a tiny pinch of astrology in the algorithms as well. With high refresh rates one gets nicely colored and in a way harmonic noises and on some settings effects or even melodies. I’m still in the process of polishing and rewriting the software bit so wont include it here (yet). End result is this:

Soothing sounds of TANR.

As in my previous workshops, no PCBs were used. Instead spot board and insulated metal wire was used. New innovation on this workshop was to use a photo with final layout between components and the board to help with placement of the components. I have to say that project like this starts to be at the limits of spotboard technique and might be that after working months with DIMI, I’m fluent Eagle user, could have proper PCBs made in the future iterations. Although I think it is useful to master creating circuit boards from scratch with spot board.

Workshop results!

Workshop participants and couple finished synths!

As always I’m up to giving this workshop few times in the future. This workshop is suitable with people with previous experience on soldering and it takes around 5 hours to finish. Drop me a line if you would be interested in organizing one!

synakynä schematics

I gave a workshop as part of Super Public Art School (for a second time) in Titanik Gallery 6 June 2013. The topic was a hand shake between visual and sound arts: a synthesizer pencil. I named it Synakynä (a pencil synth in Finnish). Below you can witness some fooling around with first working (after many failed) prototype.

Synakynä is augmented version of drawdio but it uses ATtiny85 microcontroller instead of a 555 timer. This greatly expands the sonic range of the instrument. At the workshop, preprogrammed ATtinys are provided, but if you wish to modify the code and upload it by yourself, source code for Synakynä is available and written using Arduino IDE. One also needs to install ATtiny definitions. To upload the code you can use either ISP programmer or Arduino board as described in previous link.

To play Synakynä, you need to draw continuous and as thick line as possible on paper while touching one end of the line with your other hand. This will cause a small current to flow through the circuits of the pencil, your drawing and your body (study the diagram above for the details). The microcontroller is measuring amount of current and using this information to alter pitch of the synthesizer and tempo of blips. It is also possible to replace pencil with more or less anything (fruits, food, skin) that has similar resistance. Feel free to experiment.

The current code has multiple different modes written into it. Every time Synakyna is switched on, different mode will be chosen.

Parts list:

  • Pencil (HB,2B, as soft as possible)
  • Piezo
  • ATtiny85 (+ optional 8-dip socket)
  • 300k resistor
  • 680pF capacitor
  • Power switch
  • Battery holder (2032)
  • Battery (2032, 3V)
  • Piece of spot board (22×9 holes)
  • Metal wire, uninsulated
  • Wire
  • Piece of aluminum foil or copper tape

Tools needed:

  • Soldering iron and solder
  • Wire strippers
  • Knife or saw
  • Pencil sharpener

The circuit board is constructed on spot board by using thin metal wire to form the actual circuit. It is a neat little technique that is for some reason surprisingly rare. Compared to etched or strip boards this technique allows improvising the actual layout of the board on the fly without spending huge effort on layout design. Those not keen on improvising can find a fairly compact layout below.


Synakynä layout suggestion.

Stuff drawn with pen are on the copper side of the board while parts drawn with pencil are on top side of the circuit board. Pay attention for the trace going to the left leg of the piezo. It should go past the trace coming from the power switch at the top side of the board. Diagram is from the top side (the side the components are) of the board.

pkas paks

Above you’ll see results of the workshop. Ten synths were built and all of them successfully. Well done!


EQ-1. Buttons on the left define the octave. Buttons on the right define note. Pot defines waveform.

EQ-1. Buttons on the left define the octave. Buttons on the right define note. Pot defines waveform.

This is a simple synthesizer designed to somewhat replicate the user interface of electric tambura (or trumpet) of legendary Finnish synthesizer Sähkökvartetti (Electric Quartet). During past few years I have had a priviledge to play and perform with this custom synth that was built and designed by Erkki Kurenniemi for Finnish folk artist M. A. Numminen. As there is only one instrument in existence, I decided to built my own pocket version of one of the many controller units Sähkökvartetti consists of. On the video below you can see the original synth being used by the band sharing the name of the synth, Sähkökvartetti.

The operation of this instrument is slightly modified from original. I have mixed the operation logic of another Kurenniemi synth, DICO in it. Similarly than on Sähkökvartetti, all parameters are digitally encoded on both synths, but the actual coding differs a bit, making DICO more suitable for tonic output. The buttons on the left are used for select the note. Each button will transpose note to a certain interval up/down. On Sähkökvartetti, these intervals would be minor and major second, major third and minor sixth. With these intervals by counting numbers from 0 upwards will give you a chromatic scale. While this is totally logical, musically it makes hard to play melodies. In DICO different intervals are selected. These are minor third, fourth, fifth and a tritonus. Musically these intervals make much more sense although playing scales would again be a bit of a struggle.

Two buttons on the left are used similarly as in DICO to select the octave to be used. On original Sähkökvartetti they would have been used for turning filters on and off.

This synth is built around ATMega168 chip, running 8Mhz without external crystal. The code is modified and cleaned version of nebulophone. That explains the potentiometer on the center (not absent in Sähkökvartetti) that is being used to select waveform (square, saw, triangle, noise) similarly than the waveform pot on nebulophone.