Tuesday, September 18, 2012

Populated Eurorack Modular

I guess I should take a photo of it with all the modules in place.
An empty case doesn't look that exciting. It looks far better now :)
Truth be told, I haven't really been using it a lot (or any other of my gear for that matter) for a while now.
I'm lazy... Uninspired... Plus, my interest in these things comes and goes.
Enough talk. Here's the photo :)

Looks a bit messy with the wires, but that's what it's like to use it!
For the sake of completeness, I'll list all the modules currently installed in the case.
In order of appearance, from left to right, starting with the top row:

Doepfer           A-190 MIDI-CV/Sync Interface
Livewire          Audio Frequency Generator

Analogue Systems  RS-95 VCO
Doepfer           A-114 Dual Ring Modulator 
Doepfer           A-116 Waveform Processor
Doepfer           A-118 Noise/Random
Doepfer           A-148 Dual Sample&Hold
Doepfer           A-156 Dual Control Voltage Quantizer

Doepfer           A-170 Dual slew limiter
Doepfer           A-180 Multiples
Doepfer           A-144 Morphing Controller
Doepfer           A-135 Voltage Controlled Mixer
Bubblesound       uLFO
Doepfer           A-145 LFO
Doepfer           A-143-3 Quad LFO
Doepfer           A-180 Multiples 

Doepfer           A-181 Multiples 2
Doepfer           A-131 VCA Logarithmic
Doepfer           A-140 ADSR Envelope
Doepfer           A-140 ADSR Envelope
Doepfer           A-121 12dB Multimode Filter
Doepfer           A-122 24dB Low Pass 2 (CEM Type)
Doepfer           A-106-5 12dB SEM Type VCF
Doepfer           A-167 Analog Comparator

As you can see, it's mostly Doepfer. As you perhaps also can see, there's still some space down in the lower right corner :)
I'm not sure what to get. I don't really feel I need anything at the moment as I'm not using it as much as I was hoping for.
Maybe that'll change some day. For now, it'll do ;)

Brief explanation of how it works
For those of you who are unfamiliar with how a modular synthesizer works, I'll just describe it very briefly and simplified.

Up in the top left corner there's a MIDI-CV/Gate-converter. It converts incoming MIDI data to:
A CV (Control Voltage) signal and a Gate (key down) signals.

The CV is typically used to control the pitch of one or more oscillators so you get a frequency that follows what key you play on the keyboard. For example one note might be generating a CV of 1 Volt. Play one octave up and you have a CV of 2 Volts instead.

The Gate signal is simply indicating whether a key is pressed or not. Usually this is 0V for no key pressed and 5V for key pressed.

By nature, this is monophonic (one pitch and one gate signal, so only 1 key at a time is represented) but it is possible to have more elaborate setups with polyphonic operation, though it requires a lot of modules...

A very simple patch (Hence the name patches on "modern" synthesizers) may be like this:
The CV from the MIDI-CV/Gate module is patched to a VCO CV-Input. This causes the VCO to generate a tone.
Different outputs from the VCO provides different waveforms, for example a sawtooth wave.
Let's say you patch the VCO sawtooth output to the audio input of a low-pass VCF (filter) module.
You can set the VCF cutoff frequency and resonance as you like.
You then patch the VCF output to the input of a VCA (amplifier).
The amplifier is the final stage. From there, you connect the output of the VCA to your mixer.

However, you might also want to connect the Gate signal to the trigger input of an Envelope generator (typically ADSR).
You can set the Attack, Decay, Sustain and Release values as you wish and take the output of the envelope and patch it to the CV-input of the VCA that was mentioned above.
The CV-input on the amplifier controls how much to amplify the audio signal.

Messy? Yes. Endless possibilities...
You now have a basic patch corresponding to a simple monophonic analog synthesizer.
A fun thing is that the modular doesn't usually distinguish CV signals from Audio signals or even trigger signals. They're just voltages!
That means you can connect an audio signal as CV-input to an oscillator...

This description is barely scratching the top of the ice-berg of analog modular synthesizers.

The purpose of buying this was to have an extremely flexible synthesizer, capable of having different sound characteristics (depending on oscillators, filter types, etc).
You can buy oscillators based on for example classic CEM3340 chips.
You can buy different filter modules based on TB303-filters, Wasp-filter, Moog-filters, etc...

The downsides, of course, are that you can't "save" patches and you have to keep patching those cables between all the modules. I think I need some more cables! :)

I find that I mostly sit and experiment with it, but don't really do anything useful.
Perhaps I'll use it for something serious some day :)

No comments:

Post a Comment