Synthi V

How it works

Matrix semi-modular

The Synthi is a subtractive modular synthesizer in miniature: sources (oscillators, noise) and processing modules (filter, ring modulator, envelope shaper, reverb, outputs) are not connected to each other until you insert pins into a matrix: each row is an output (source), each column an input (destination); a pin at the intersection creates the connection. The advantage is a complete modular without cables, with the panel always visible and patches that can be described with coordinates (e.g. I10 = keyboard to the pitch of oscillator 1).

Audio and control signals

The same outputs can go to audio inputs (filter, ring mod, envelope, reverb, outputs) or to control inputs (oscillator frequency, cutoff, decay, reverb mix, output levels). A slow oscillator on the cutoff gives a wah; the same oscillator at a fast rate gives FM; noise on the pitch gives instability; the main output fed back into an input gives feedback.

Diode filter

The Synthi's low-pass filter uses a diode ladder instead of a transistor one: it has a more irregular, rubbery character; with medium Response it behaves almost like a band-pass (it emphasizes the cutoff and drops the lows), with high Response it self-oscillates, producing a playable sine.

Trapezoidal Envelope Shaper

The envelope has four stages: Attack (rise), On (hold at maximum), Decay (fall, which also acts after release) and Off (pause before restarting): with Off at minimum the envelope repeats on its own like an LFO with a trapezoidal shape. It has a control output (Trapezoid) and an internal VCA for audio (Env. Signal).

Ring modulation

The ring modulator multiplies two signals, producing only the sum and difference frequencies: with non-simple ratios the result is metallic and inharmonic (bells, alien voices).

Digital sequencer

The AKS included one of the first digital sequencers: it records up to 256 events like a tape recorder and plays them back in a loop, transposable from the keyboard.

Character and tone

Raw, unstable, wild sound: drifting oscillators, a squelchy diode-ladder filter that is less polished than the Moog ladder (a relative of the TB-303 sound), resonance that goes into self-oscillation easily, a noisy spring reverb and a matrix that invites unorthodox connections. It excels at filtered noises, effects, drones, hypnotic sequences and sounds on the border between music and sound design. Aggressive basses and gritty mids, often harsh highs. Limitations: only three oscillators, a single peculiar envelope (trapezoidal with looping), less precise tuning (Quantize was added), few clean keyboard sounds; it is not the instrument for lush pads or pop basses. Compared to Buchla Easel V it is more chaotic and subtractive; compared to Modular V and ARP 2600 V it is more compact, dirtier and unpredictable; compared to Korg MS-20 V it shares the aggressiveness but is more experimental.

Architecture

Original EMS

• EMS founded in London in 1969 by Peter Zinovieff, Tristram Cary and David Cockerell; VCS3 (1969), Synthi A (1971, briefcase version), Synthi AKS (1972, with touch-plate keyboard and KS digital sequencer), Synthi 100.
• 3 oscillators: Osc 1 sine and sawtooth, Osc 2 square and triangle, Osc 3 square and triangle in a low range (useful as an LFO); Shape for symmetry.
• Noise generator with Colour; diode low-pass filter/oscillator with Response (self-oscillating); ring modulator; trapezoidal envelope shaper with Attack, On, Decay, Off and two outputs; spring reverb; X/Y joystick; two output channels with LP/HP filters and controllable levels; external inputs with preamplifiers.
• 16 × 16 pin matrix with resistive pins of different attenuation.
• KS capacitive keyboard with 256-event digital sequencer (real-time recording, loop, transposition).
• Monophonic.

Synthi V (Arturia, 2019)

• TAE modeling with oscillator instability; 304-point matrix (19 sources × 16 destinations) in Modern (clean) or Vintage mode (crosstalk and leakage between adjacent pins as on the hardware).
• 100/75/50/25% attenuator pins and group pins A, B, C, D controllable by the advanced modulations.
• Additions: Quantize on all oscillators, Sync between Osc 1 and Osc 2, Sample & Hold module with Sync and Slew, Mono/2/3/4 polyphony.
• Emulated keyboard sequencer (256 events, Sync or Free, Pitch Spread for keyboard and sequence, transposition, random, envelope trigger choice).
• Advanced: 5 Functions (multi-segment envelopes up to 16 points, loop, key trigger, sync, presets), animated Joystick (path of up to 8 points, rate per segment, loop, retrig ×1–8, random Generate, mod wheel on Y), 32-step step sequencer with smooth and directions, syncable LFO, parameter and group matrix (sources such as velocity, aftertouch, mod wheel, keyboard).
• 3 effects slots in series or parallel: Reverb, Delay, Analog Delay, Chorus, Flanger, Phaser, Overdrive, Compressor, BitCrusher, ParamEQ.

The controls, one by one

Oscillators 1, 2, 3

Frequency (blue knob)

Tuning: Osc 1 and 2 from 0.6 Hz to 16.75 kHz, Osc 3 from 0.015 to 500 Hz (ideal as an LFO).

Quant

Locks the frequency to the nearest semitone (Arturia addition): essential for playing in tune.

Shape (green knob)

Waveform symmetry: turns sine into sharper shapes, square into pulses, triangle into sawtooth; it has no effect on Osc 1's sawtooth.

Sync

Hard sync of Osc 2 to Osc 1: moving Osc 2 changes the timbre while keeping the pitch.

Level (two white knobs)

Levels of the two waveforms of each oscillator (Osc 1: sine and saw; Osc 2 and 3: square and triangle), present as separate rows in the matrix.

Noise Generator

Colour

Character of the noise: 5 = neutral wideband, toward the right brighter (white), toward the left warmer (pink).

Level

Noise level.

Filter Oscillator

Frequency

Cutoff of the diode low-pass filter.

Response

Q/resonance: 0–5 soft low-pass; 5–7 aggressive, almost band-pass; 7–10 self-oscillation with a sine whistle (playable by connecting the keyboard to Filter Freq).

Level

Filter output level.

Ring Modulator

Inputs A and B (matrix)

Two signals are needed, otherwise silence.

Level

Ring output level.

Sample and Hold (Arturia addition)

Rate (blue)

Sampling frequency, free in Hz or synced.

Sync

Free or locked to tempo (in bars).

Slew (green)

Transition speed between values: 0 = sharp steps (with possible clicks), high = soft rubbery curves.

Level

Output voltage level.

Envelope Shaper

Attack

Rise from almost instantaneous to over 1 s.

On

Hold time at maximum after the attack (hold); a light indicates attack and on.

Decay

Fall (equivalent to release), from instantaneous to over 10 s; changes the overall duration.

Off

Pause before the automatic restart: at maximum (7–10, Manual) it does not repeat; lowering it makes the envelope cycle by itself (trapezoidal LFO, rhythms).

Trapezoid (output level)

Level of the control output (Trapezoid row of the matrix); when also used as audio it adds an attack boom/tick.

Signal (output level)

Level of the audio processed by the internal VCA (Env. Signal row).

Attack switch

Manual trigger: held down, the envelope stays in On.

Reverberation (spring)

Mix

Dry/wet balance (0–10) with imperfect separation as on the hardware; modulatable from Reverb Mix in the matrix.

Level

Reverb output level.

Joystick

Range X and Range Y

Scale the axis outputs (0–10).

Joystick

Two-dimensional control: Stick X and Stick Y rows of the matrix (e.g. X on the cutoff, Y on the pitch or the reverb mix).

Pin Matrix

Sources (rows 1–19)

Output 1 and 2 (feedback), Osc 1–3 (two rows each), Noise, Keyboard, Sequencer, Filter, Trapezoid, Sample & Hold, Env. Signal, Ring Mod, Reverb, Stick X, Stick Y.

Destinations (columns A–P)

Audio inputs: Sample & Hold, Output Ch. 1–2, Envelope, Ring Mod A and B, Reverb, Filter. Control inputs: Osc Freq 1–3, Decay, Reverb Mix, Filter Freq, Output Ch. 1–2 Level.

White pin and attenuator pins

Click = 100% pin; click and hold, then drag for 75%, 50% or 25%; right-click to remove.

Group pins A–D

Pins linked to the group controls of the advanced panel: a single macro for several connections, modulatable by LFO, step sequencer, mod wheel, aftertouch.

Output Section

Output Filter Ch. 1 and 2

Single-knob filter: 5 = neutral, to the left low-pass, to the right high-pass.

Pan Ch. 1 and 2

Stereo position.

Level Ch. 1 and 2

Output levels, modulatable from the matrix (they can let sound through even when turned down).

Main Volume

Master volume, not modulatable: the real master.

Keyboard Sequencer

Keyboard

Monophonic like the original or up to 4 voices (Poly).

Sequence Transpose

The notes you play transpose the sequence according to the interval from the first note.

Sequence Synchronization (Sync / Free)

Synced to the DAW or free.

Sequence Length

Actually the playback speed of the 256 events (0–10 free or in bars in sync).

Play

Starts and stops (always restarts from the beginning).

Record

When stopped it erases and arms recording; during playback it records as overdub.

Pitch Spread Realtime and Sequence

Interval between adjacent keys for live playing and for the sequence: semitones, microtones or stretched scales; also as a filter or reverb control.

Envelope Shaper Switch

The envelope is triggered by the sequencer, by the keyboard or by both.

Random

Generates a random voltage on the keyboard (recordable in the sequence).

Bottom bar

Matrix (Modern / Vintage)

Perfect matrix, or with crosstalk and leakage between nearby pins like the hardware.

Poly

Mono, Poly 2, 3 or 4.

MIDI Ch, Panic, CPU

Channel (All or 1–16), note reset, load.

Advanced — Functions (5)

Destination and Amount

Destination parameter and bipolar amount ±100%.

Editor (up to 16 points, curves)

Points with Point, Level (0–1), Time (0–1); arrows for curvature.

Loop, Key Tri, Total Length, Sync

Cycle, restart on every note, total duration in seconds or bars.

Presets

Common envelope shapes to load and edit.

Advanced — Animated Joystick

Path (up to 8 points)

Points on the X/Y plane that the joystick travels when you play a note.

X and Y destinations (2 per axis) with Amount

Up to four parameters moved by the path.

Map Modwheel to Y

The mod wheel moves the Y axis.

Point, X, Y, Rate

Numeric editing; Rate for each segment.

Reset, Generate

Clears the path or generates a random one.

Loop, KeyTrig, ReTrig Multiple (×1–8)

Infinite repetition, restart on every note, number of repetitions without loop.

Tempo Sync, Rate Multiplier, Range X/Y

Synchronization, global speed and axis scale.

Advanced — Groups Mod

Step Sequencer (Pencil, Line, Eraser, Random, Reset)

Up to 32 drawable steps.

Free Run, Steps, Step Length, Smooth, direction

Independence from the transport, 1–32 steps (odd numbers for polyrhythms), step length (bars or seconds), glide 0–100%, Forward, Backward, Ping-Pong, Random.

LFO: shape, Rate, Sync, Key Retrig, Once

Modern syncable LFO; Once turns it into a one-cycle envelope.

Parameters tab

Modulation matrix with amounts ±1.000: sources such as keyboard, velocity, aftertouch, mod wheel, step sequencer, LFO to almost every parameter.

Groups tab (A–D), mute and scaling

Same matrix but toward the group pins; Offset per group and column scale −1/+1; dimmed letters = muted group.

Advanced — Effects (3 slots)

Serial / Parallel

Chain or parallel; each slot with power, choice and Wet/Dry.

Reverb

Damping, MS Mix, Predelay, Decay, Size, Input LP and HP.

Delay

Time 2–2000 ms or sync (straight, triplets, dotted), Width, Ping Pong, Feedback (up to infinite loop), HP and LP.

Analog Delay

Time, Feedback, Tone, LFO Depth and Rate.

Chorus

LFO Shape, Voices 1–3, Delay, Stereo Mode, Depth, Freq, Feedback.

Flanger

Shape, Polarity, Stereo, Freq, Min Delay, Depth, Feedback.

Phaser, Overdrive, Compressor, BitCrusher, ParamEQ

Phase sweep, saturation, dynamics control, bit and sample rate reduction, parametric EQ.

Sound design tips

Minimal patch, then chaos

• The basic patch: Osc 1 → Output Ch. 1 and 2; Keyboard → Osc Freq 1 (with Quant on); then insert the filter (Osc → Filter, Filter → Output) and finally the Envelope (Filter → Envelope, Env. Signal → Output). Add one pin at a time.
• Use the attenuator pins (25–50%) for modulations: 100% pins are often too strong and quickly lead to noise.
• If the sound is inexplicably loud or distorted, check the white levels along the path and the pins going to Output Level: the outputs sum.

Diode filter

• Response 5–7 gives the squelchy acid sound but removes bass: for bass lines keep Response at 3–5 and a low cutoff, modulated by the Trapezoid.
• To play the self-oscillation as a fourth oscillator, connect Keyboard to Filter Freq with an attenuated pin and tune it: the tracking is not perfect, so use it for nearby notes.

Envelope Shaper

• Remember that Decay also acts after release and that Off decides whether the envelope repeats: for normal keyboard sounds keep Off at maximum (Manual).
• Low Off with short Attack and Decay = autonomous rhythmic pulsation; sync it with the Functions or the step sequencer if you need precise timing.

Frequencies and control

• Noise and resonance produce strong energy between 1 and 6 kHz: use the Output Filter toward LP or the ParamEQ to tame the highs in long textures.
• Deep bass is not its strong point: for subs, pair it with a clean sine oscillator (Osc 1 sine with Shape centered) and cut everything else below 100 Hz.
• The ring mod doubles the spectral density: with two oscillators at a consonant interval (fifths, octaves) it stays musical, with random ratios it turns to metal.

Feedback and vintage matrix

• Output 1/2 fed back into the matrix create feedback: use 25% pins and keep your hand on the Main Volume.
• Vintage mode adds crosstalk: authentic character but less predictable; for precise patches use Modern.

Expression

• Velocity and mod wheel do not exist on the original panel: use them through the Parameters or Groups tab (e.g. velocity on Filter Freq, mod wheel on group A controlling several pins).

Common mistakes

• Forgetting Quant on the oscillators: out-of-tune notes when you play melodies.
• Leaving the output channels' Level modulated by pins: the sound doesn't go away when you turn them down; use the Main Volume.
• Expecting an ADSR: the envelope is trapezoidal and should be thought of as attack–hold–fall–pause.

Presets to recreate

In genres and records

• Progressive and psychedelic rock: Pink Floyd built On the Run with the sequencer of a Synthi AKS and used the VCS3 (the same EMS engine in a different case) on Obscured by Clouds, The Dark Side of the Moon and Wish You Were Here, where it holds up the pulse of Welcome to the Machine; King Crimson used the VCS3 on Lizard and Earthbound; Pete Townshend ran a Lowrey organ through the filter of a VCS3 for the Won't Get Fooled Again demo.
• Art rock and ambient: Brian Eno used the Synthi AKS on many albums, also to treat his voice and the guitars of Robert Fripp and Phil Manzanera; he played the Synthi in the early Roxy Music.
• Krautrock, kosmische and French electronic music: Tangerine Dream and Jean-Michel Jarre used the VCS3.
• Synthpop: Depeche Mode used a Synthi AKS during the recording of Music for the Masses.
• Radiophonic and experimental electronics: the BBC Radiophonic Workshop used the VCS3; Todd Rundgren is among its users; Howie B used it on U2's Pop.
• Noise and industrial: Merzbow used it on Door Open at 8 AM.
• Ambient and drone: drones with the joystick and the matrix.
• Experimental techno and acid: rubbery basses from the diode filter.
• IDM, glitch and modern sound design; soundtracks and trailers: noises and textures.
• Post-rock, modern psychedelia, horror synth.