Phaser
White key 7. Sweeping notches with resonance, free-running or locked to the tempo (after the SP-404MK2’s Phaser and the Elektron Tonverk’s Phase 98).
| Knob | Page 1 | Page 2 |
|---|---|---|
| 1 | Rate, in two halves: left of the centre free, 0.02 Hz to 50 Hz; from the centre right on the tempo, 1/16, 1/8, 1/4, 1/2, 1 bar, 2 bars, 4 bars (default 0.7 Hz, free) | Mix |
| 2 | Feedback: the resonance between the notches, up to 85% (default 34%, the knob at 40%) | Stereo: the right channel’s sweep up to half a cycle behind (default off) |
| 3 | Depth: brings the notches in and widens the sweep, up to 2.5 octaves either way of the centre (default 0, off) | Band |
| 4 | Centre: the frequency the sweep moves around, 100 Hz to 6.4 kHz in octaves (default 800 Hz, in the middle) | Level |
- Rate (knob 1), two halves on one knob. Left of the centre it runs free, from 0.02 Hz
(a sweep a minute) to 50 Hz (a buzz), on the flanger’s curve. From the centre right it
follows the tempo, as the filter’s LFO does: 1/16 on the centre,
then 1/8, 1/4, 1/2, a bar, 2 bars and 4 bars at the top, a cycle each. So turning right goes
faster in the free half, and from the centre on, slower again, through the divisions; the
two halves meet where both are fast. The knob’s LED shows the half: the phaser’s colours
(violet to orange) while free, green on 1/16 to yellow on 4 bars once synced.
- Turning it by hand: 1% a detent in the free half, a division per 3 detents in the synced half. Turning up out of the free half stops on 1/16 first; turning down from 1/16 takes 3 detents back into the free half, just below the centre.
- SHIFT + turn: 10% steps in the free half, a division a detent in the synced half, across the centre both ways.
- Synced, the sweep is at the centre on the beat and rises first, like the filter’s LFO, its beat counted from the loop’s start (or from when the clock locked).
- Feedback (knob 2) sends the chain’s output back into it: the notches sharpen and the peaks between them ring, up to 85%. The peaks get louder with it; it’s turned down a little to make up.
- Depth (knob 3) brings the phaser in: at 0 the sound passes untouched, whatever the other knobs say. Over the first fifth of the knob the notches fade in, and from there on it only widens the sweep, up to 2.5 octaves either way of the centre at the top (from 800 Hz: 140 Hz to 4.5 kHz). A morph fades the phaser in and out on it.
- Centre (knob 4): where the sweep is centred; SHIFT + turn moves it in octaves.
- Stereo (page 2’s knob 2): the right channel’s sweep lags the left’s, up to half a cycle, so at the top one channel’s notches go up while the other’s come down.
- In the resonator’s loop: with the resonator on, its ringing goes through the phaser on every trip, so the sweep moves through the resonances.
- Level: a phaser takes some of the sound into its notches, about 3 dB of a full mix, more with feedback up; page 2’s Level is there for it.
- How it works: six allpass stages in a row on each channel, the sound added to them, and feedback from the end of the chain back into it. They cut three notches into the sound, the middle one on the sweep’s frequency, one about two octaves below it and one about two above; a triangle LFO sweeps them up and down in octaves around the centre (knob 4).
- LEDs: the key is violet; the knobs go violet to orange, the rate’s synced half green to yellow.