DX7 V

How it works

FM synthesis in brief

Frequency modulation synthesis (FM, actually phase modulation in Yamaha's implementation, patented by John Chowning at Stanford and licensed to Yamaha) uses one oscillator to rapidly vary the frequency of another. If the modulator oscillates at audio frequency, you don't hear a vibrato but new harmonics appear, the sidebands, at frequencies equal to the carrier plus and minus multiples of the modulator (fc ± n·fm).

Operators

Each operator is a sine oscillator with its own envelope and its own amplifier (output level). An operator that goes to the output is a carrier: you hear its frequency directly. An operator that feeds into another is a modulator: you don't hear it as a note, you hear its effect on the carrier's timbre.

Ratio = which harmonics

The frequency of each operator is set as a ratio relative to the note played. With integer ratios (carrier 1, modulator 1, 2, 3…) the spectrum is harmonic: 1:1 gives a full series similar to a sawtooth; 1:2 favors the odd harmonics and recalls a square wave; 1:3 or 1:4 give more nasal timbres. With non-integer ratios (1:1.41, 1:3.5, 1:7.07) the sidebands don't fall on the harmonics and the sound becomes inharmonic: bells, metals, gongs.

Modulator level = modulation index = brightness

The output level of a modulator defines the modulation index: at zero the carrier is a pure sine; as you raise it more and more sidebands appear and the sound opens up. It acts like a filter, but in a nonlinear way (individual harmonics rise and fall in waves, following the Bessel functions). That is why the modulator's envelope is the real timbre envelope: a modulator with a fast decay produces a bright attack that darkens, like a piano or an EP.

Algorithms

The algorithm is the fixed wiring scheme of the 6 operators: stacks of modulators above a carrier, several carriers in parallel, or all in parallel (algorithm 32 = additive synthesis of 6 sines). The DX7 has 32 of them. Several carriers in parallel let you add different timbres together (for example a body + a metallic attack), while long chains produce very dense spectra.

Feedback

Every algorithm has a feedback loop: one operator modulates itself. With a little feedback a sine gradually becomes a sawtooth; with a lot it becomes noise. It is the main source of roughness and noise in the DX7.

Scaling

Level scaling lowers or raises an operator's level according to the note (less brightness in the highs, more body in the lows), while rate scaling shortens the envelopes on high notes, as happens in acoustic instruments.

Character and tone

A digital, crystalline, well-defined sound, very present in the highs (2–8 kHz), with sharp transients and percussive attacks that no subtractive analog synth gets easily. It excels at timbres with an inharmonic or metallic spectrum (bells, mallets, EPs with the tine in the attack) and at tight, punchy basses that leave room for the kick. The spectrum changes over time in a natural way because each operator has its own envelope, so the sounds breathe like acoustic instruments (bright at the attack, darker in the decay). Limitations: no filter in the original (brightness is controlled only through the modulator levels), warm, fat pads are less natural than on Jup-8 V or CS-80 V, programming is not very intuitive, and there is a risk of harsh or aliased sounds at high indices. Compared with Synclavier V (4-voice-per-partial FM with timbre frames) it is more rigid but more pop; compared with CZ V (phase distortion) it is more complex and inharmonic, while the CZ sounds closer to a filtered analog; compared with SQ80 V it is less dirty and less wavetable. Vintage mode (12-bit DAC with companding) adds the grain and slight noise of the original, while Modern is cleaner.

Architecture

Original Yamaha DX7 (1983–1989)

• Digital FM synthesis with two dedicated Yamaha chips (OPS for the operators, EGS for the envelopes); about 200,000 units sold, the best-selling synth of its era.
• 16 voices of polyphony, monotimbral; 6 sine operators per voice, 32 algorithms; one feedback loop per algorithm (0–7).
• Each operator: Ratio mode (coarse 0.50–31, fine, detune ±7) or Fixed (1, 10, 100, 1000 Hz with fine); output level 0–99; envelope with 4 rates and 4 levels (R1–R4, L1–L4, 0–99); velocity sensitivity 0–7; AM sensitivity 0–3; keyboard level scaling with breakpoint and left/right curves (−LIN, −EXP, +EXP, +LIN) with depth 0–99; keyboard rate scaling 0–7.
• One pitch envelope with 4 rates/4 levels common to all operators.
• A single global LFO (waveforms: triangle, falling and rising sawtooth, square, sine, sample & hold), with speed, delay, PMD (pitch depth), AMD (amplitude depth), pitch mod sensitivity 0–7 and key sync.
• No filter, no effects; mono output through a low-resolution DAC with analog companding (characteristic grain).
• 61-key keyboard with velocity and aftertouch; 32 internal memories plus cartridge; MIDI.
• Factory sounds programmed by Dave Bristow and Gary Leuenberger.

What DX7 V (Arturia, 2017) adds

• Up to 32 voices of polyphony and unison up to 32 voices with Unison Detune; poly/mono mode with portamento and glissando (Retain/Follow in poly, Fingered/Full-Time in mono).
• Extended Ratio from 0.25 to 64, Fixed from 0.37 Hz to 20 kHz, detune ±15.
• 25 waveforms per operator (not just sine) with an Invert button and Osc Sync (phase reset).
• Individual feedback for each operator in addition to the algorithm's.
• A resonant filter per operator (LP, BP, HP) with key follow.
• Pan for each carrier: native stereo.
• Three envelope types per operator: original DX7, DADSR, MSEG up to 16 points with loop and tempo sync; three global envelopes (Pitch, Mod 1, Mod 2).
• Original or Modern level scaling up to 32 points.
• Two multi-waveform syncable LFOs, a modulation step sequencer up to 32 steps, a 24-routing modulation matrix with up to 8 sources/destinations each, 4 macros.
• Arpeggiator (6 modes, 1–5 octaves, sync).
• Up to 4 effects in series or in two parallel pairs (Phaser, Flanger, Analog Delay, Delay, Analog Chorus, Reverb, Param EQ, Filter, Overdrive, Destroy, Compressor).
• Vintage DAC (12-bit with companding and multiplexing noise) or Modern; original velocity range (16–109) or full.
• Import of the original DX7's SysEx banks.

The controls, one by one

Top panel (basic view) — Globals

Volume

Master volume from −80 to +24 dB (double-click = 0 dB), responds to CC 7. Keep it around 0 dB and leave headroom: with many carriers in parallel and unison the level rises quickly.

Transpose

Chromatic transposition of the preset over a 4-octave range. Useful for bringing an FM bass into the right register without changing ratios.

Tuning

Global fine tuning (−64/+63). For matching recordings not at 440 Hz.

AMD

Global depth of amplitude modulation by the LFO. It only affects operators with AM Sensitivity > 0: on a carrier it gives tremolo, on a modulator it gives a timbre tremolo (wah).

PMD

Global depth of pitch modulation by the LFO (vibrato). Low values for natural vibrato; it is often left at 0 and the vibrato is routed to the mod wheel via the matrix.

Pitch Mod Sensitivity

Vibrato sensitivity (works together with PMD): it multiplies the effect of PMD. With PMD at zero nothing happens.

Top panel — Data entry / Macro

Macro Sliders (4)

Four renamable sliders that drive groups of parameters assigned in the Mods page (e.g. Brightness = modulator levels, Time = rate multiplier). Ideal for automation and MIDI controllers.

Top panel — Algorithm and quick edit

Algorithm window

Shows the carrier/modulator layout; use the arrows or drag the number to choose one of the 32 algorithms. Right-click on an operator = mute. Changing the algorithm transforms the sound because it changes who is audible and who modulates.

Feedback

Amount of the algorithm's feedback (the loop drawn on the diagram). A little feedback makes the sine more jagged and rough; a lot gives noise and dirt. Its effect adds to the operators' individual feedback.

Pitch EG

Depth of the global pitch envelope for all operators with the Pitch EG button on. Small values for the attack chirp of basses and kicks, large ones for effects.

Poly

Switches between polyphonic/monophonic (mono with auto-priority, like the original). Mono for basses and leads with portamento.

Top panel — Portamento

On

Enables the glide between notes.

Gliss

When on, the glide moves in semitones (chromatic glissando) instead of continuously.

Time

Glide duration. 30–120 ms for bass legatos, 200–500 ms for expressive leads.

Top panel — Arpeggiator

On

Turns on the arpeggiator.

Hold

The arpeggio continues after the keys are released.

Sync

Locks to the DAW tempo; Rate becomes a subdivision from 1/1 to 1/64. When off, Rate goes from 0.010 to 50 Hz.

Rate

Arpeggio speed (1/16 for typical 80s sequences).

Pattern

Note Order, Up, Down, Up & Down inclusive, Up & Down exclusive, Random.

Octave

Arpeggio range from 1 to 5 octaves.

Bottom bar — Utility

Velocity

Chooses between the DX7's original velocity range (16–109, about 30 values) and the full MIDI range 0–127. For imported presets use the original; the full range gives more dynamics but can make velocity-sensitive modulators blow up.

Unison

Number of voices stacked per note (up to 32). Active in poly too: if you don't use Unison Detune, leave it at 1 to save CPU.

Poly (voice limit)

Polyphony limit: 1–8, 16 (like the original) or 32 voices.

MIDI Channel

MIDI receive channel (All or 1–16).

Panic

Silences hanging notes.

CPU

CPU load meter.

Advanced — Overview: operator selection

OP1–OP6 (Freq/Ratio and Level)

For each operator: frequency (Coarse and Fine in Ratio from 0.25 to 64; in Fixed from 0.37 Hz to 20 kHz) and level slider. Ctrl/Cmd+click for multi-edit. A carrier's level is volume, a modulator's is brightness.

Mute (right-click on OP)

Mutes the operator: if it is a carrier, its stack of modulators goes silent too; if it is a modulator, the carrier remains but loses that modulation. Great for understanding what each operator does.

Copy/Paste

Copies all the parameters of an operator (frequency, level, oscillator, filter, envelope, scaling, output) to another.

Advanced — Overview: Oscillator window

Oscillator On/Off

Turns off only the oscillator: if it is a carrier, its modulators become audible (the next one in the stack becomes the carrier) and still pass through that operator's filter and pan.

Wave

25 waveforms per operator (the original sine and richer variants). A non-sine waveform on a modulator greatly increases the sidebands: use it at low levels.

Invert

Inverts the wave's polarity; it changes the cancellation between parallel carriers and the shape of the spectrum with feedback.

Detune

Fine detuning ±15. Two carriers at ±2–3 produce the beating/chorus typical of DX EPs.

Ratio / Fixed

Ratio: the frequency follows the keyboard. Fixed: constant frequency across the whole keyboard, for mechanical noises, attack clicks, formants, percussion.

Osc Sync

Restarts the wave's phase on every new note: identical, punchier attacks (essential for basses and kicks); when off, each note starts from a different phase and sounds livelier.

Pitch EG

Makes the operator follow the global pitch envelope (Ratio mode only).

Advanced — Overview: Envelope and Level Scaling

Envelope (Point, Time, Level, Slope)

Editor for the operator's output envelope: choose the point, the time to reach it, the level and the curvature (0 linear, positive exponential, negative logarithmic). Ruler for zoom and scrolling; up to 16 points in MSEGs. On a modulator operator, this is the timbre envelope.

Curve style

Chooses DX7 (original) or Modern scaling.

Breakpoint

MIDI note where the left curve turns into the right one (C3 = middle C). Typically around C3–A3.

Curve (L and R)

Shape to the left and right of the breakpoint: +Lin, −Lin, +Exp, −Exp. On a modulator, −Exp on the right makes the highs less shrill; +Lin on the left gives the lows more bite.

Depth

Intensity of the curve (the graph doesn't change). Moderate values of 20–50 for natural corrections.

Modern: Point, Level, Note, Slope

Free curve up to 32 points with level, note and slope for each point: useful for correcting specific areas of the keyboard.

Advanced — Overview: Filter

Filter on/off

Enables the operator's filter (Arturia addition). It works even with the oscillator off, filtering the stack below it.

Filter mode

Resonant Low-Pass, Band-Pass or High-Pass.

Keyboard follow

The cutoff rises with high notes: it keeps the relative brightness constant.

Cutoff

Cutoff frequency (center in BP). An LP at 3–6 kHz on the carrier removes digital harshness without touching the character.

Resonance

Emphasis at the cutoff; with high resonance the FM takes on an almost analog color.

Advanced — Overview: Output

Operator Feedback

The operator's individual feedback (in addition to the algorithm's, the effects add up). Little = more harmonics, a lot = noise.

AM Sensitivity

The operator's sensitivity to the LFO's amplitude modulation (0–3), tied to the global AMD.

Velocity Sensitivity

How much velocity affects the operator's level. On a modulator = dynamic brightness (the secret of expressive EPs); on a carrier = volume.

Pan

Stereo position (carriers only): two carriers panned left and right widen an EP or a pad.

Advanced — Overview: Global settings

Pitch Bend Range

Pitch bend range up to ±24 semitones (2 typical, 12 for basses and leads).

Pitch Bend Step

0 = continuous bend, 1 = in semitones, up to 24 = in wider jumps. Interacts with Range (the jumps don't exceed the Range).

Polyphony (Mono/Poly)

Duplicates the panel's Poly button.

Unison Detune

Detuning between the unison voices (requires Unison > 1): with 3 voices the center one stays in tune. Low values for thickness, high ones for a supersaw effect.

Portamento Mode

In poly: Retain (the first note stays, the new one glides) or Follow (the held note follows the new one). In mono: Fingered (glide only when legato) or Full-Time.

Waveform display

Oscilloscope of the overall output: useful for seeing the effect of feedback and indices.

DAC Resolution

Vintage: emulates the 12-bit DAC with analog companding and multiplexing noise (80s grain and warmth). Modern: dedicated DAC per voice, cleaner.

Advanced — Envelopes

Operator/envelope selector

Selection of the envelopes of the 6 operators (colored like the operators) and of the three global ones: Pitch, Mod 1, Mod 2. Hover to compare shapes of the same type.

EG Mode

DX7 (original 4 rates and 4 levels), DADSR (Delay up to 30 s, Attack, Peak, Decay, Sustain, Release; Sustain can exceed Peak), MSEG (up to 16 points with slope, loop and sync).

Keyboard Rate Scaling

0–7: shortens the envelope on high notes. 2–4 for realistic pianos and EPs.

Rate Multiplier

Speeds up or slows down the whole envelope from 0.1× to 10× (synced: 0.125–8).

MSEG Templates

8 unsynced and 7 synced shapes as a starting point.

Points/Time/Level/Slope (MSEG)

Point editing; double-click = sustain point; Shift+click moves all the following points.

Bipolar

Pitch and Mod only: the envelope goes from −1 to +1 (e.g. pitch that falls and rises again).

Loop

Loop between two points chosen with the flags while the key is held: rhythmic envelopes and cyclic movements.

Sync, Grid Length, Resolution

Syncs the MSEG to tempo; Grid Length (4–128) defines the active part, Resolution the grid for inserting points (1/4…1/32).

Advanced — Mods: matrix, LFO, sequencer

Modulation matrix

24 routings over three pages (1–8, 9–16, 17–24), each with up to 8 sources or 8 destinations; drag the little square for the amount (positive or negative). Sources: LFO, envelopes, velocity, aftertouch, mod wheel, macros, an operator's level or keyboard scaling, sequencer… Destinations: operator parameters (level, ratio, filter, DADSR points), LFO, sequencer, FX, arpeggiator.

LFO 1 and 2 — Wave

LFO waveform (menu or arrows).

LFO — Speed / Tempo Sync

Free speed or in subdivisions of the DAW tempo.

LFO — Delay

LFO fade-in: vibrato that arrives after the attack, like a player would do.

LFO — Key Sync

Restarts the phase on every note (on for rhythmic effects identical on every note; off for free movement).

Sequencer — On, Sync, Free Run

Modulation step sequencer (it must be routed in the matrix to be audible); Sync to the DAW; Free Run = does not restart on every note.

Sequencer — Randomize, Clear

Random values on all 32 steps, or reset to zero.

Sequencer — Steps, Step Length, Direction

2–32 steps; step length from 1/32 to 8/1 (sync) or 0.01–10 s; reading direction.

Sequencer — Pencil/Line, Ramp/Gate

Step drawing tools; Ramp creates gradual transitions, Gate stepped steps.

Advanced — FX

Routing Series / Parallel

Four slots in series (top-left, bottom-left, bottom-right, top-right) or two parallel pairs; each slot has on/off and Wet/Dry.

Phaser

Two stages with separate Rate and Depth, Sync, Feedback, Dual Mode, Stereo, Wet/Dry.

Flanger

Delay Time, Depth, Rate, positive or negative Feedback, Wet/Dry.

Analog Delay

Solid-state delay: Time, Feedback Tone, Feedback Amount, LFO Rate and Depth (slight pitch instability), Wet/Dry.

Delay

Digital 9 ms–1 s: Sync, Time, Feedback, Ping Pong, Wet/Dry.

Analog Chorus

Type (simple, medium, complex), Stereo Width, Rate, Amount, Delay, Wet/Dry: indispensable on EPs.

Reverb

Pre-delay, Room Size, Width, Tone (left cuts highs, right cuts lows), Tame (less rumble, more highs), Gain, Wet/Dry.

Param EQ

Three bands: Lo/Mid/High Freq, Lo/Mid/Hi Gain, Mid Width; draggable graphic view.

Filter

LP/HP/BP filter with Cutoff, Resonance and Wet/Dry on the global output.

Overdrive

Drive, Tone, Output, Wet/Dry: from light grain to distortion.

Destroy

Bitcrusher: Clipping, Bit Resolution, Tone, Harmonic Distortion, Resample, Gain, Wet/Dry.

Compressor

Input, Threshold, Ratio, Attack, Release (and output level): controls the peaks of FM transients.

Sound design tips

Think in carriers and modulators

• Before touching anything, look at the algorithm and mute the operators one by one: you'll understand who plays (carriers) and who colors (modulators). A carrier's level is volume, a modulator's level is brightness.
• The modulator's envelope is your filter envelope: a modulator decay shorter than the carrier decay = a bright attack that darkens, the natural behavior of pianos, plucks and mallets. If the modulator lasts longer than the carrier, the sound stays harsh until the end.

Ratio and spectrum

• Integer ratios = harmonic sound. 1:1 ≈ sawtooth, 1:2 ≈ square (odd harmonics dominant), 1:3 and 1:4 more nasal, 1:5 and above = sibilant and glassy.
• Non-integer ratios (1.41, 3.5, 7.07, 0.5 with detune) = inharmonic: perfect for bells and metals, terrible for basses and pads that need to stay in key.
• A high-ratio modulator (14, 17, 19) with a very short decay (20–60 ms) creates the tine or attack click: it's the trick behind electric pianos and slap basses.
• Use ratio 0.5 modulators only with caution: they generate components below the fundamental and make the bass muddy.

Modulation index

• FM is not linear: as you raise the modulator level the harmonics don't grow uniformly, some disappear and reappear. Move the level slowly and listen: often the best spot is earlier than you think.
• High indices on high notes produce aliasing and whistles: use level scaling (−Exp curve to the right of the breakpoint on a modulator) or the filter's key follow.
• A touch of feedback (10–25%) enriches the sound, beyond 60% it becomes noise: useful for breaths, wind and hi-hats, not for clean tones.

Frequency management

• FM basses are often too rich between 1 and 4 kHz: keep the modulator index low or apply the operator's LP filter at 2–3 kHz so the bass doesn't clash with vocals and snare.
• For subs, keep a pure carrier (sine 1:1 or 0.5:1) with no modulators below 100 Hz and put the grain in another, higher carrier: the sub stays stable and mono-compatible.
• DX EPs live between 200 Hz and 5 kHz: with a high-pass at 80–120 Hz and a slight cut at 2–3 kHz they sit in the mix; chorus widens them without filling up the lows.
• FM bells have strong energy at 3–8 kHz: in dense arrangements lower the modulator instead of using EQ, and the sound stays more natural.

Velocity and expression

• Assign velocity to the modulators (not just the carriers): when you play hard the sound gets brighter, like a real instrument. Values of 3–5 out of 7 are a good start.
• With the full velocity range, the original presets can come out too harsh at high velocities: go back to the original range or reduce the modulators' velocity sensitivity.
• Rate scaling 2–4 on the envelopes makes pianos, mallets and plucks realistic (high notes shorter).

Common mistakes

• Picking the algorithm at random: start from 5 (three pairs in parallel) or 32 to understand, then move on to longer stacks.
• Leaving Unison > 1 without detune: it wastes CPU and can cause strange phasing.
• Basses with Osc Sync off: every note has a different attack; turn it on for consistency and punch.
• Long releases on all operators: modulators in release keep generating harmonics and the sound smears; shorten the modulators' release.
• Forgetting the DAC mode: Vintage adds noise and grain that pile up across many tracks; use Modern if you need cleanliness.

Presets to recreate

In genres and records

• 80s pop and power ballads: DX7 presets become a trademark of the decade; in 1986 it is used on 40% of the number ones on the Billboard Hot 100. The E Piano 1 preset is used by Whitney Houston, Chicago, Phil Collins, Luther Vandross, Billy Ocean, Celine Dion and George Michael; the DX7 is also on When Doves Cry by Prince, The Best by Tina Turner, Smooth Operator by Sade and Smooth Criminal by Michael Jackson.
• Synthpop, new wave and 80s rock: the Bass 1 preset is on Take On Me by a-ha, Danger Zone by Kenny Loggins and Fresh by Kool & the Gang; the Bass 2 preset plays the main riff of Take My Breath Away by Berlin.
• 80s country and R&B: in 1986 E Piano 1 appears on 40% of country number ones and 60% of R&B number ones.
• Japanese electronic music: Ryuichi Sakamoto is among the early users, on Rosé by Mari Iijima and on his own Ongaku Zukan.
• Ambient: Brian Eno programs it extensively and uses it for Apollo: Atmospheres and Soundtracks, then in his productions for U2 and Coldplay.
• Video game music: chips derived from the DX7's, such as the YM2612, power the Sega Mega Drive.
• Smooth jazz, fusion, gospel, city pop: FM electric pianos, basses and marimbas.
• Vaporwave, future funk, synthwave: they sample or recreate 80s FM timbres.
• Techno, house, drum and bass, dubstep: FM basses, metallic stabs, modulated growls.
• Hip hop, lo-fi, trap and K-pop: melancholic electric pianos, FM bells and mallets.