I'm featured in the new issue of Black Panels Only Eurorack Zine! I highly recommend you go get yourself a physical copy. You can read a bit about my synth and how I used the modules for recording my latest album.

Hi everyone, here's a video auto-biography about my artistic journey I'd made during the winter of 2020. It's showing how I started, the road I travelled and where I ended up. Lots of footage of my works, concerts, behind the scenes etc. Thanks for watching!

DIY Modular #1: Wooden case and CRT-monitors.

Hola amigos y amigas! :-) Besides enjoying a long summer holiday, before starting on my master's degree in electronic music, I've been rethinking my entire setup and decided to abandon the idea of having lots of separate boxes which I have to arrange and connect for every concert and instead jump on the modular wagon but with my own standards and designs. (no "eurocrack" ;-P ) I am going to design and build every module from scratch and include some different and unique modules and parts and try different methods of circuit designing. The frontplates are going to be transparent so all the insides are visible, which adds an extra dimension the the machine - it will be an work of art, from circuit to interface.

I wanted something organic and easy to work with so I went with wooden frames for the cases and for the front- and backplates I chose transparent acrylic glass as it's neat to be able to see the insides of the machine. I will put a lot of emphasis on the aesthetics of the circuits, parts and components because of this. For attaching the acrylic frontplates I am going to use an alu-rail with rectangular 'slide nuts' as the width of the modules will vary.
In the future I want to be able to expand with further identical cases on top so I added a mechanism for attaching the frames to each other. The drawing above shows my vision of what the machine will ultimately end up looking like.

Some snaps of the cases / frames:

Wooden frames with plexi back plate

Single frame / case

Both frames attached

I found it crucial to start with the design of the power supply part. I had an old PSU from a laptop lying around - 19V DC with app. 5A of juice to play around with. Some of the parts will be quite power-hungry so in the future I might have to step it up to 10A. I found a cute old capacitor from Denmark and decided to use it as stabilizing cap. My plan is to have most of the modules run on  ±12V but I might add a 5V line as well but so far I've been using LM317 variable voltage regulators for each device.

Power connector and switch w/ LED

Rear view - large capacitor added

Personal notes on PSU

The first actual modules will be a 'terminal' with a green-monochrome CRT TV. It will receive a video signal from an Atmega328 generating simple text strings with data such as the temperature inside the box, total run time, date and time and a lot of other stuff.
Next to it another CRT TV of the same size will display the master stereo output as a simple oscilloscope. Beneath the TV I will install two analog VU meters with a nice warm backlight as well.

Shelf for the TV's and front plate test	Side view of the shelf	Rear view of the CRTs
Both TVs turned on!	VU meters on as well. :-)	Startup-text generated by the arduino

An analog current panel meter will be beneath the terminal showing the power usage for alle the modules. Each TV draws around 1000 mA but so far 5A in total should be enough. I've used 7812 regulators for each TV to supply 12V but the regulators turn very very hot and will shut off without proper cooling so I had to mount rather large heatsinks.
The plan is to mount front plates in front of the TV's and have all the knobs and in/outputs controlling the TV and the terminal.

For labels I want every front plate etched with a CNC router (or just by hand?) and then edge-light it with an LED-strip installed beneath the acrylic. A test looks like this (scrap acrylic with scratches):

LED-strip test

Edge-lighting test

Edge-lighting test

Debut album released on DIY audio player

For my bachelor-degree project I decided to pile together various recordings and compostions collected during the past years I've been under my alias Dögenigt and make an album.

For a long time I'd been thinking of an alternative to the digital release or vinyl and what have you and I discovered a tiny circuit based on a miniature arduino-like chip (ATtiny85) which can be programmed to read lossless quality sound files from an SD-card and play them (in 44.1 kHz 16 bit) via the PWM pins.
So I decided to go ahead and build the circuit into a small audio player to be built into some casing as my album and have the project and journal revolve around that.

I've been working on the project for the past couple of weeks - it's all in the papers I wrote.
Link to the paper in danish: http://data.xn--dgenigt-q1a.dk/DIEM/opgaver/BA3-Bachelorprojekt.pdf
I tried to translate into english but failed to do so. Let me know if you have success!

Images from the project:

Wave-player based on ChaN's circuit and code:
Runs of 3.3V and outputs sound directly to jack output in 44.1 kHz 16-bit sound. So far, only mono as more digital pins are needed. The PWM-outputs on the ATtiny85 each create an 8-bit signal, when 2 are added together they make 16-bit. For stereo 16-bit sound 4 digital pins are needed. We didn't have enough time to do this but I know of a guy who did it with an ATmega328.

    Finalized player with batterypack, speaker and SD-card.

 

    Simple version of the player with no jack output but screw terminals instead for power and output.

    Player cased inside VHS-cassette :-)

    ChaN's (simple!) circuit

The album is already online on my bandcamp as digital download but in the future I will have the release available on this platform as in the pictures above. The whole album can be bought for $10 and of course streamed for free. All the tracks are made with my homemade gear. Enjoy!

Dögenigt @ Mayhem: Noise Convention #1, 18/10/2014

I just received this footage from the Noise Convention last year on Mayhem, Copenhagen. The video is not very long but there's audio recording from the mixer of the full concert if anyone's interested.

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 :-)

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.

Aristoteles Logic Synth Update #2: Oscillators

The next module on the path of Aristoteles, the 'lunetta-style' synth, is finished! It's the central part of the synthesis: Oscillators. 8 of them. So essentially one could patch all 8 oscs into the 8-channel mixer and have 8 voice polyphony. They will also serve as the unique pseudo-CV clocks for the other modules, which is the main concept of CMOS-based synthesizers. The brain in all this is the classic 40106 chip, which is actually a logic NOT-gate flipping on and off. Below is a quick demo.

The oscillators have the following functions, as seen on the image to the right: The first switch lets you choose if the osc should be constantly on or momentary, determined by the red button. This allows one to use the synth as a simple keyboard with a little willpower. Next switch allows you to add extra capacitance to the oscillator, thereby setting the frequency range. The middle position of the switch is actually an off-position so the oscillator runs on the "offset cap" which is too small at the moment, so the frequency is very high. I wanted to have this range-switch so I could go with a potentiometer value around 100K for the frequency knob. This makes it easier to tune it without too big steps, as one gets if running on 1M or something in that range. I chose to have the whole synth only producing square waves, to have it ultra lo-fi and simple. But I  thought it could be nice to at least have PWM for each osc though, so this is what we have below the freq pot.

 It's a simple diode technique for adjusting pulse width of the wave, but I discovered that it was actually an inverse PWM, for what I wanted. It was setting the lenght of the off-time, not the on-time, so the LED's would be constantly on, only turning off for a short time, so I used another 40106 to inverse the HIGH/LOW order. This is the reason for 3 of the chips in the design - 2 IC's for getting 8 oscs and another one plus the leftover gates from IC 2 to have the pulses inversed.

The LED's are switched on and off with the help of transistors, to minimize voltage drop on the outputs. All the outputs are grounded with 100K resistors as well to prevent frying the chip if you touch the banana jacks.

Here's my quick and dirty schematic drawn in MS paint :)
Feel free to use it for inspiration in your own designs.

Aristoteles Logic Synth Update #1: MIXER

Oh what a spring it's been! I was bedridden for about a month which really zapped all my creativity and I've slowly recovered now to bring back my mind on what is the icing on my cake of life: electronic gadgeting.

So just around New Years Eve I posted a picture of my newly assembled modular synth casing - no intestines yet though! But just before my bed claimed me for a minor lifetime, I was able to finish up the first and central part of the system: the 8-channel mixer with simple BP/LP filters + power supply.

Here's a demonstration of what I am talking about:

So the idea is that you have 8 channels in the mixer which are summed together after they've passed the filter circuit and the respective volume knob. When using stackable banana-jacks one might ask why bother with a multi-channel mixer; why not just stack 'em on top of each other and using passive resistor/diode mixing?
The problem for me was that mixing with just resistors would cause each output from every oscillator to drop in voltage and maybe cause instability with edge-detection in the chips they would enter - and diodes make distinctive modulation when used for summing. Which is why every output enters a diode, so it's still possible to mix signals together in a single mixer channel if one is running low on free channels. Other than that, diodes make sure that no cross-talk occurs if stacked for multiple operations.

Some pics:

The power supply was super simple, just a power switch and momentary N/C button to switch on  and off and discharge the 470uF cap to get the power starve effect. Starving only affects the CMOS-chips used for sound generation, the mixer circuit isn't affacted by the variable supply voltage.
I will discuss the other modules in future entries and here's some schemes for the willing.

Greeting Card Sampler Boxed

I finally got to finish up my project seen in this previous post: Voice Message Greeting Cards turned into Lo-Fi Sampler. It's the 'voice message recordable greeting card' I hacked into a small looper with playback speed bend, now in a neat little encasing I found in a thrift shop. I think it's a intercom from the 70's, quite nice.

The video shows the features which are: potentiometer for varying the playback speed, switch for selecting loop mode, red button on the side is for restarting the device, which re-triggers the message, switch for selecting between the inputs - electret mic or input jack, jack for sending output to an amplifier and in the bottom are two banana jacks which allows you to control the device with a vactrol or light sensor, or any other resistive sensor :)

I had a very nice day at the FabLab's Maker's Day in Copenhagen, where I held a small symposium and a koncert with my current setup. One of the guys from CEO Bendorama who also played, got a recording of my concert - which includes the Greeting Card Sampler. (Thanks John!)