AndreasKrebsBlog

This is a complicated, long (25 minutes)  and not too easy-to-listen work. Sorry for that. There are six different voices which seem to be independent (but are not independent, of course):

We start with a somehow rhythmic clicking. Basically, this is an A-117 Digital Noise Generator put into an A-188-2 Tapped BBD. The two sum outputs of the BBD are sent into two A-108 Ladder Filters which are modulated by two slow LFOs. BBD frequency and Noise Generator frequency are controlled by an A-198 Ribbon Controller (pressure and position).

Then we have some kind of bass drum. Old and cheap “trick”: a self-oscillating filter (here: an A-101-1 Vactrol VCF) is sent into a VCA (here: A-131). Both are controlled by an A-140 ADSR, the filter frequency is also controlled by an A-155 Sequencer. There’s some white noise fed into the filter to add some grittiness.

There’s an additional clicking thingy: this is a little bit more complicated: Two slightly different tuned A-110 VCOs (Square outputs) are fed into an A-172 Max/Min Selector. This somewhat esoteric module selects the current minimum of both waves and puts the result into an A-115 Audio Divider (low frequency divisions boosted here). Not enough dirt yet? We go into an A-124 Wasp Filter, modulated by an A-143-1 Complex Encvelope Generator (first stage only) and an A-142 VC Decay/Gate. Final Stage is another A-131 VCA.

The next “voice” is some kind of “snare drum” (sorry for this slightly incorrect real world analogy). Coloured noise (from an A-118 Noise Generator) is fed into an A-127 VC Resonance Filter and then into an A-137-1 Wave Multiplier I (which makes noise even noisier). Waveshaper and VCA (A-132-3) are modulated by the full A-143-1 Complex Envelope Generator, which does some complex envelopes here. The VCA output is fed into an A-134-1 VC Panning module, modulated by an A-147 VC LFO. The first stage of the Complex Envelope (decay threshold) sends a reset trigger to the A-147.

Finally, we have two beautiful tonal voices (appearing after 9:30 something): Three A-110 VCOs controlled by a second A-155 Sequencer, put into an A-132-3 VCA and then into an A-151 Sequential Switch. The first two switch outputs are sent into an A-106-5 SEM filter, the second one into an A-105 SSM Filter. Both filters and VCA are modulated by an A-140 ADSR.

Then we have some interconnectiuons, especially for clock/trigger signals: A-160 Clock Divider, A-165 Trigger Modifier, A-162 Trigger Delay were used.

Here we go:

http://www.andreaskrebs.de/assets/media/improvisation-20100607a.mp3

Track length is 24:58.

Have fun, 

Andreas

The A-137-1 is a four-fold waveshaper (kind of four simplified A-136es in one box?). Technical details can be found on Doepfer’s Homepage:

http://www.doepfer.de/A137.htm

The example uses a single A-111 VCO (triangle output) which is controlled by an A-155 Sequencer. The A-137-1 has four modulation inputs: number of multiples, folding (distortion) level, symmetry of folding (i.e. positive and negative amount) and harmonics (additional harmonic created). Three LFOs (a slow, a medium and a fast one) and a S&H (synced to the sequencer) are used via A-138m matrix mixer to modulate the Wave Multiplier.

Here we go:

http://www.andreaskrebs.de/assets/media/A-137-1.mp3

Andreas

This is a simple tune with a complicated setup. Basically, there are four “voices”:

The piece is starting with a high percussive tone. A single A-110 VCO put into an A-137-2 Wave Multiplier II and then into an A-106-5 SEM Filter. The sequence is controlled by an A-155. The sequencer’s clock is slightly random-based: An A-118 Random is divided by an A-160 Clock Divider, the result modified in length by an A-162 Trigger Delay and then amplified (i.e. gated) by the modified clock output (rising and falling edge from an A-165 Trigger Modifier) of an A-154 Sequencer Controller (which directly drives the second A-155 which controlls the bass voice). The SEM output is amplified by an A-132-3 and then put into an A-134-1 Pan (LFO controlled). The A-137-2 is modulated by an A-143-8 Quadrature LFO.

Then we have said bass voice: Two A-110 and an A-117 are mixed and put into an A-105 SSM 24dB Lowpass Filter. Amplification by an A-131 (which is a bit more “retro” than the A-132-3). This voice is controlled by the second A-155 Sequencer.

Third voice is an atonal growling something. Two A-110 VCOs are put into an A-115 Divider, resp. an A-163 VC Divider (LFO modulated), everything is mixed and put into an A-127 VC Resonance Filter and then (after amplification via A-132-3) into an A-188-2 Tapped BBD. Everything is controlled by an A-198 Ribbon Controller. Since the internal highspeed oscillator of the BBD produces audible sounds when tuned down, the two outputs of the A-188-2 are filtered by two A-108 48dB Ladder Filters. Frequency of filters and BBD is controlled by pressure output of the ribbon.

Voice Nr. four is a drone-like sound. A single A-110 is put into (a) an A-137-1 Wave Multiplier I, (b) an A-126 VC Frequency Shifter, (c) an A-196 PLL. Everything is mixed and routed via A-138m 4×4 Matrix Mixer. Then we go into an A-124 Wasp Filter and an A-131 VCA. The A-137-1 is modulated by two LFOs (from an A-143-3 Quad LFO), the A-126 is modulated by an A-146 Variable Waveform LFO.

As usual, everything was recorded without overdubs, pure A-100, just some additional FX from Ableton Live and mastering in Cubase.

Here we go:

http://www.andreaskrebs.de/assets/media/improvisation-20100602a.mp3

Track length is 15:05.

Have fun, 

Andreas