Aristoteles Logic Synth Update #5: Sequencer

I couldn't hold myself back after finishing the AND-gate module for dear Aristoteles so I dug up the schematic I drew for the 10-step sequencer module and jumped right in. In the video below I'll demonstrate how it works and the possibilities are vast! Combined with the AND-gates it's very convenient for creating melodies and patterns.

The sequencer is based on the '4017 CMOS Decade Counter' which counts from 0 to 9; adding 1 every time a clock pulse is received on the CLK input. It has 10 outputs going high/low one at a time depending on the current count. Only one output at a time can be high; the one corresponding to the count.
There's a reset pin which decides when the counter will reset to 0 so it's possible to have it count to any number below 9. I've implemented a rotary switch for setting the count from 9 to 0. If the reset pin is set to ground, the count limit will be set to 9 (default).

If an audio range signal is sent to the clock pin and one listens to one of the outputs, you get harmonic intervals when reducing the count limit. This makes sense as it only takes half the time to count to 5 instead of 10.
The frequency ratio to the frequency we get when counting to 10 (which can be seen as our fundamental) can be calculated by dividing 10 with the desired count. So the relation between i.e. 10 and 5 (10/5) is 2. We multiply our fundamental with this number to calculate the interval, which in this case would be an octave.
The chart below shows the intervals we get when we're adding the value of the fundamental - which is what happens every time we add a step for the counter. Interesting stuff!

Multiple of fundamental	Ratio within octave	Common name	Hz and chroma (Example)
1x	1/1	Fundamental	110 (A2)
2x	2/1	Octave	220 (A3)
3x	3/2	Perfect Fifth	330 (E4)
4x	4/2	Octave	440 (A4)
5x	5/4	Major Third	550 (C♯5)
6x	6/4	Perfect Fifth	660 (E5)
7x	7/4	Harmonic Seventh	770 (G5)
8x	8/4	Octave	880 (A5)
9x	9/8	Major Second	990 (B5)
10x	10/8	Major Third	1100 (C♯6)

As is the custom, I've attached the scheme for the circuit for this module. It's not that intricate, just LED's and output jacks on each output. I see that I forgot to add the transistor LED-drivers, but it's just as usual - look in the schematics for the other Aristoteles modules to see how they should be wired.
I've used a 12 position rotary switch for the reset switch, I couldn't find any 10-pos so 2 of the positions are grounded which just sets the count limit to 9 (all 10 steps). It can be tricky to find out which pins correspond to the switch positions but easy enough when using a multimeter for testing continuity between the output and the desired pin.

I will post all my stripboard layouts in a single package when I am finished with the last module :-)

 UPDATE 7/2-15:

My brother and I (as the duo SNU) had a really nice jam with the Aristoteles modules so far.  Here's a video of  our session when the sequencer was still on breadboard. I had my Clock Box (which also runs on 40106 and 4040 oscillators) control the power for the 4017 so a lot of modulations back and forth.

Aristoteles Logic Synth Update #4: Logic Gates

I thought it was time for building the next module for dear Aristoteles, my 'lo-fi logic synth project' so I did the logic gate module which consists of 8 AND gates with 2 inputs and an LED for the output. The truth table on the right describes how the gate will behave: the output only goes high (1) when both inputs are high. The result is a very simple form of amplitude modulation, or it can be used to control the path of signals from the other modules with counters or LFO's, you name it.  The video below speaks for itself.

In the video I demonstrate the effect of the 3 different frequency ranges on the oscillators: LFO range signals are good for 'letting through' audio range signals at a certain rate for "beep beep beep beep" sounds. 2 audio range signals will generate complex pulsating modulations and beatings when adjusting the pulse width.
Setting the range to the high pitched setting on both oscillators will generate classic vintage radio-like modulation squeeks. I also tried using the 'octave divider module' for one of the inputs which has its own unique sound.

I chose to have all the logic gates as AND gates. For a long time I was in doubt about wether to have a pair of XOR or NAND gates just for the hell of it but I could not find a good reason as they don't do much sound-wise where as the AND gate is so clear in its function and I want to be able to make complex signal paths with counters, dividers, random clocks and all eight oscs - all controlling each other through the gates. 

I am already starting on the 10-step counter 'cause I cannot wait to have each step 'open' a unique oscillator with different frequencies!

The circuit is very simple, I basically just wired the in- and outputs straight to the 4081 but attached 100K resistors on each pin to prevent static electricity from the end of the wires going into the chip when patching.
LED's are controlled by transistors as always to prevent voltage dropping on the outputs.

UPDATE:
I had my brother a.k.a. SNU over and he fell in love with the new module which resulted in hours of wiggling.
Here's a a little peak of the tweak :-)

Terrestrial Signals III Live concert @ DIEM Elektro 'Pulse'

A late happy solstice to all of ye - I have been ind bed for most of the holidays, guess my body and mind was in need for some rest, it's hard work wanting to do you own thing and the following concert you are about to witness required a lot of planning and soldering.
I found out I was booked to play at the next of DIEM's obligatory student concerts 'DIEM Elektro' - this specific concert was called 'Pulse' so I prepared some pulsating light-controlled rhytms with a hacked monotron, using only the nice korg filter with a photoresistor, clock-synced to the notorious MicroWaveSampler by my Clock Box. I included my electromagnetic plasma ball synth described in the post below. I was pretty content with the outcome although some of my gear failed a bit, including my little TV-to-sound device. To much noise on the line to gain it. Anyways, please check out the video - it was shot by my brother Alec Sander and with his GoPro Hero camera attached to my head so you get the P.O.V. close up shots from my perspective. Enjoy!

I have a line of projects planned for this year, as I am writing my bachelor project which I think will focus on alternative media for releasing album material, more to come on that. After the last concert I finally chose to sucumb to the idea of a modular system instead of all these seperate modules which has to be wired together on set, it's too much hazzle every time I need to set up for a concert so now I will jump into building a complete modular system with the same principles used so far: analog means of sampling, tape delays and quirky little circuits. Stay tuned!

Lot of love, Dogenigt

Audiovisual concerts: Plasma globe and 'TV light-to-sound effect'

Hi guys, I've been busy preparing for a couple of live shows I've been doing over the last month or so. I've been really into the idea of having an electromagnetic source translate into both light and sound at the same time as to have it as an audiovisual mini-installation on stage.

First experiment I wanted to test out was to "read" the video signal from a small monochrome CRT TV with a photocell (just wire a jack plug onto an ordinary solar cell or what have you) and having played around with translating sound to light with these small TV's I thought I wanted to try and combine both of these:
converting sound -> light and from light -> sound again! Kind of like a CRT-TV effects pedal of some sort.

I explain it all in the video beneath but I am using both a regular B/W TV where I send a sound signal into the composite video port which shows up on the screen as horizontal lines flickering in synch with the audio and then I tried with one of my TV-oscilloscopes and a photcell as well. The result is surprisingly interesting as it resembles the original signal quite a lot but still alters it in a distorted, fuzzy, gated kinda way.

I am thinking of developing the TV with a small board before the TV to adjust the signal in various ways, could be really neat! But already you have the brightness and contrast knobs with which you can make the sound only appear on the screen when it reaches a certain intensity level bright enough for the solar cell to detect it, thus making some gating mechanism.

Here's a concert I played in a cold war bunker here in Aarhus. I brought both TV's along together with my sampler, my cacophonator and greeting card sampler to be able to mix various signals to be sent into the TV's. Tye sampler spew out a weird bleeping sound for every clock for its step sequencer so I had to switch over to dry signal with that. I've learned a fair share of do's and don'ts since the first gig with this setup! :-)
Here's a small clip from the concert - event was called 'DIEM Elektro: Isolated Space')

Simultaneously I'd been exploring the wonders of electromagnetic induction coils for picking up various "hidden sounds" in electronic equipment and one night at my rural summmers house I had the pleasure of toying around with my brothers large plasma globe and thought it could be insane to eavesdrop to a plasma globe with the coil. Got a very cheap usb/5v-powered one and the sounds it spurts out through the coil is just heavenly! Such a pure electronic signal, striaght from the source :-)

This one I also  plan to evolve into an actual instrument with controls for all kinds of stuff, power supply and modulating the frequency of the coil and os on - lot's to come in the future! Here's a concert where I use the plasma ball "synth" - the sound might not do it much justice as my sampler was filled to burst with weird organic noise samples.

Thanks for looking, hope it sparked some inspiration in you - I myself couldn't help but to send dear Dr. Tesla a thought every once in a while listening and looking to the zapping electrodes of the plasma globe 3:-)

Solder Timer

My friend Carl Dimsos has designed a nifty way to make sure you don't forget to turn off your hot soldering iron, so he made this Solder Timer (danish: lodde-timer) with a small ATtiny85 microprocessor, basically a very small version of your beloved Atmega (DIP) chip you find in the arduino.
The potentiometer sets the count-down time before the USB-power to the power socket gets turned off. The switch below resets the timer/turns it on or off. LED's are indicating whether the power to the socket is on or off.

Solder timer with soldering iron

The timer

Intestines

I am very pleased with the finish and I love this tool for our workshop! It's so convenient just to push a switch to turn on your soldering iron instead of fumbling with the power cord every time.

You can get the Solder Timer Kit from DimsOs - they have a webpage dedicated to this project on dimsos.dk/loddetimer/

You can obtain the pre-programmed ATtiny85 from DimsOs. The usb-power socket might be a bit tricky to get your hands on outside Denmark, but maybe eBay. If not, write me and I will help out.

Carl's Prototype Timer

Vero board layout

Schematics

Composition for Acoustic Sequencer

I was invited by Acoustic Sequencing to make a composition for their installation called 'Galathea', which is a camping wagon filled with electric motors hitting on the interior and various instruments inside.
They are powered by an arduino with a power relay shield - controlled by Max, turning MIDI notes into serial commands.

My composition in the demo video below I chose to call 'Polterwagen' inspired by a poltergeist possessing an entire house and making noise with the interior. A better recording should come soon, this is just a promo for those who can make it to Aarhus Sound Festival 2014 this weekend where Galathea is installed.

It was good fun to compose for a "robot orchestra", trying out the different notes in the sequencer to see which note I should press to trigger a certain motor. With Polterwagen I was sort of pushing the limits of the equipment. The "drumkit" consists of motors hitting on a seat, a tin can, a spring and opening the fridge door! Then there are numerous motors on a xylophone and a child piano. There's also a note controlling a smoke machine and the fire alarm has been hacked as to play melodies. Very balstyrical project!

Solenoids on xylophone

Polter-piano!

Solenoid hitting on spring

Aristoteles Logic Synth Update #3: Divider (simple)

The Aristoteles 'Lunetta' synth project is slowly but steadily going in the right direction. Here's the first of the two 4040 divider modules, demonstrated in the vid below.

Here's a scheme for the willing - simple and self-explanatory!

To explain this simple circuit in a simple way, it's taking any clock output from the other modules and counting 2^n times before setting the output HIGH - 2, 4, 8, 16 and so on - up to 2^12 times, that is 4096 clocks before setting the output high.

That's quite a division, so a high frequency is needed if one wants oscillations in the audio range. Otherwise it's great for turning audio range signals into LFO clocks. All in all, it's a very musical chip as it creates sub-octaves, which are relations of a factor of 2 to the input frequency.

I was flipping through Roads' Computer Music Tutorial one evening and began to read up upon the very first digital systems with flip-flop logic gates and discovered that the method of dividing down a master clock to acheive other tones is ancient! So-called 'divide-down tone synthesis' was discovered in 1930 so this method is almost a century old!

Compositions on Bandcamp

Hi lovely people! Hope you're enjoying your summer.
I've created a bandcamp store where you can get some of my releases in lossless format.
Some of the compositions might appear on a future debut album, which I intend to release online and on a physical medium which will be quite different from your typical CD/LP format.

Link to my bandcamp is found by clicking on 'Releases' in the top menu.

The latest track I've finished is called Plate Phonetics and consists of recordings of cuts and scratches on blank phono records which gives weird rhytmic patterns. On top of it I've added some tones with feedback oscillator (Derek Holzer's soundbox) and recording of my homemade string instrument.




The other tracks available so far, you might've heard on my soundcloud. They are 'Subtlle Visit' composed during a meditation and creativity workshop with Kim Cascone and 'Veins of The Robot' composed with Christina Kubisch during a workshop with her on DIEM where we brought her electromagnetic headphones in the city of Aarhus.
'Entraining Patterns' is made solely from homemade equipment: the wavetable synth, Vibrati Punk Console and passive ring mod. There's also a composition made with The MicroWaveSampler.