AndreasKrebsBlog

This is a weird piece. More nerd doodling than music, perhaps…

 Setup is quite minimal: one oscillator, one filter, ADSR and VCA. However, to achieve the desired sound, an A-155 Sequencer (partly controlled by an A-154) is used as an oscillator here. But let’s start with the primary source of all events: the random output of an A-118 Noise Generator. This random signal is sent into an A-156 Quantizer and then to filter frequency and to the LFO frequency that triggers the oscillator frequency. As a trigger LFO, I use an A-143-9 (which is quite unusual, but helpful, since it can achieve quite high frequencies. The sine waves trigger the sequencer anyway…).

As mentioned before, the Sequencer is the VCO here. Waveform is drawn by adjusting its step potentiometers. Frequency is controlled by said LFO, but I use the A-154 to control mode and first step of sequence. Mode: driven by a slow triangle LFO (A-146), I change the sequencer mode: forward - backward - pendulum (results in 1 oct down) - random (results in colored noise) and back. First sequencer step is changed by another slow LFO (A-147 sine out). This results in playing a kind of arpeggio melody (related to mathematical exact shortening of waveform cycles from 8 to 2 steps in the sequencer running at audio speed).

Sequencer (VCO) output is then sent into an A-106-5 SEM filter which is controlled by (a) random output of A-118 and (b) an A-140 ADSR, triggered by the raw VCO output: VCO out is sent into an A-199 Ext. In to get a trigger signal. This trigger controls the next “Sample & Hold” of the A-156 Quantizer (see above) and triggers the Envelope (after being processed by an A-162 Trigger Delay).

That’s it. No human interaction during the piece. No overdubs, just some mastering with Cubase after recording the track.

Here we go:

http://www.andreaskrebs.de/assets/media/improvisation-20100825a.mp3

Track length is 2:59. 

Have fun,

Andreas

In July 2010, there have been 4.141 downloads of my mp3-files (July 2009: 1.712 downloads).

Thank you very much for your interest in my music!

Andreas

Again, this is quite a long piece. Thanks for your patience during listening!

As always, there are no overdubs, just an A-100, some effects in Ableton Live and Mastering in Steinberg Cubase. Everything was played in one take. We have two “percussion” voices and two melodic/sequended ones.

A fast percussion starts the piece: the 6 oscilators out of an A-117 Digital Noise Generator is put into an A-105 SSM Lowpass Filter, then into an A-134-1 Panner and into two VCAs of an A-132-3. The VCAs are controlled by an A-140 ADSR which is triggered by some A-165, A-186-1, A160/161 combination (itself triggered by an A-154 Sequencer Controller). The panner is modulated either by an A-146 Variable Waveform LFO or (via A-182-1 Switched Multiples) by the A-155 Sequencer which controls the next percussive voice.

The second percussive voice (the slowe one) is digital noise from an A-117 Digital Noise Generator put into an A-136 Distortion/Waveshaper (this is quite some “heavy metal”, yes?) and then into an A-106-5 SEM Filter (which produces quite a beautiful sound). Both bandpass and lowpass/highpass outputs are then sent into the inputs of an A-101-3 Modular Vactrol Phaser. The two phaser parts are controlled by two independent LFOs (from an A-143-3). The two mix outputs of the phaser are sent into two VCAs of an A-132-3, which are controlled by the same A-140 ADSR. The A-140 is triggered by an A-142 VC Decay Generator which is triggered and controlled (decay time) by an A-155 Sequencer. The A-142 also controls the SEM Filter (so we have longer and shorter notes here).

Then we have a sequenced (tonal) voice: two A-111 VCOs are put into an A-114 Ring Modulator (VCO1: saw and VCO2:sine wave). The first VCO’s pitch is controlled by an A-198 Ribbon Controller (sent through an A-156 Quantizer), the second VCO’s pitch is controlled by a second A-155 Sequencer (using 16 steps via A-154 Sequencer Controller and A-150 VC Switch). The output of the ring modulator is sent into an A-137-2 Wave Multiplier (modulated by the four outputs of an A-143-9 Quadrature LFO) and then into an A-106-6 Xpander Filter (I’m using the 12 dB LP out here). After this, we go into an A-131 VCA. Both VCA and VCF are controled by an A-140 ADSR (triggered by the A-154 Sequencer mentioned above).

Now there’s the “solo” voice: three A-110 VCOs (sine wave 1 oct down, two sawtooth waves) are sent into an A-138 Mixer and then into two A-106-1 Xtreme Filters (serial connection; one in highpass mode, the second one in lowpass mode). Then we go into an A-127 VC Resonance Filter and an A-131 VCA (controlled by an A-198 Ribbon Controller). The VCA output is split up (A-180 Multiples): partly sent directly into an A-138 Mixer, partly sent into an A-188-2 Tapped BBD. BBD Output is sent into an A-108 Ladder Filter (48 dB mode to cut the BBD oscilator noise) and then into the same A-138 Mixer. Frequency of the three VCOs as well as frequency of the BBD are controlled by the A-198 Ribbon Controller (put through an A-156 Quantizer and an A-170 Slew Limiter). The VCOs are also modulated by an A-143-1 Complex Envelope Generator (for some “human” vibrato, where necessary). The two A-106-1 VCFs are modulated by an A-147 VC LFO or by the A-155 Sequencer (which controls the slow percussive voice) via A-182-1 Switched Multiples.

Here we go:

http://www.andreaskrebs.de/assets/media/improvisation-20100808a.mp3

Track length is 21:27.

Have fun,

Andreas

The triangle out of an A-111 VCO goes into an A-136, then into an A-132-3 VCA, controlled by an A-140 ADSR. VCO and ADSR are controlled bay an A-155, the Waveshaper is modulated by two LFOs (starting slow and then up to audio frequencies). LFOs are attenuated by an A-183-1 Dual Attenuator.

Technical Details can be found on Doepfer’s homepage:

http://www.doepfer.de/a136.htm

Here we go:

http://www.andreaskrebs.de/assets/media/A-136.mp3

Have fun,

Andreas