Doepfer A-101-3 Modular 12 Stage Vactrol Phaser example

Well, we probably all know the sound of a phaser. Nothing too special, although there are some famous ones around. Just one of these beautiful additional effects. The A-101-3 can do more. It offers access to inputs and outputs of all 12 shifting stages and it allows for different modulation sources for stage 1-6 versus stage 7-12.

Technical details can be found on Doepfer’s Homepage:

So I have set up a little patch to create quite wild things: three A-110 VCOs (sawtooth, one VCO is tuned down 1 oct), mixed, amplified (with an A-132-3, controlled by an A-140 ADSR) and then split (via multiple) to be put into stage 1-6 input as well as into stage 7-12 input of the A-101-3. VCO frequency and ADSR are controlled by an A-155 Sequencer. Stage 1-6 shifting is modulated by one triangle LFO (A-143-3), stage 7-12 by a different triangle LFO. LFO frequencies are changed manually during this recording.

Now here comes the fun part: shifting stages outputs 5, 6, 9 and 12 are fed into an A-138m 4×4 Matix Mixer. The four outputs of the matrix mixer (all four in bipolar mode) are fed into shifting stage inputs 1, 6, 7 and 12. This allows me to create feedbacks, feed-forwards, inverted feedbacks and inverted feed-forwards in quite complex combinations (and some really weird sounds). The two final outputs of the phaser are simply left and right audio channels with original/shifted signal mixed 50:50. Since the resonance of vactrol devices can be quite loud, I’ve put some compression and limiting on the track.

Here we go: