The Yamaha DX7, released in 1983, was the first hugely successful digital synthesiser - and the sound of countless 80s records: electric pianos, glassy bells, slap basses. Arturia's DX7 V recreates it, with the original's six operators and algorithms, plus a friendlier interface and modern extras the hardware never had.
Operators
A DX7 voice is built from six operators. Each is a sine-wave oscillator with its own envelope and output level.
- Carriers - operators you hear.
- Modulators - operators that modulate the frequency of another operator. You hear their effect, not the modulator itself.
Algorithms
An algorithm decides how the six operators are connected: which modulate which, and which are carriers. The DX7's original algorithms range from long stacks of modulators (complex, evolving tones) to several carriers side by side (closer to additive synthesis). DX7 V shows each algorithm as a diagram.
Ratio and level
- Frequency ratio - each operator is tuned as a ratio of the note played. Whole-number ratios (1, 2, 3) give harmonic, pitched tones. Non-integer ratios (1.41, 3.5) give metallic, bell-like, inharmonic tones.
- Output level of a modulator - how strongly it modulates. Higher levels add more harmonics: brighter, harsher. This is FM's equivalent of opening a filter.
Envelopes
Each operator has its own envelope. On a modulator, the envelope controls brightness over time - a fast decay gives a bright attack that mellows, the signature of FM pianos and bells. DX7 envelopes use rates and levels rather than ADSR times; take time to learn how each stage behaves.
Feedback
One operator in each algorithm can modulate itself. Feedback adds buzz and noise, turning a sine wave towards a sawtooth or white noise - useful for brass, grit and percussion.
Recipes
- Electric piano - an algorithm with paired carriers and modulators. Modulators at ratio 1 with moderate level and fast decay; a second pair at a higher ratio for the bell-like "tine" attack.
- Bass - ratio 1:1 or 1:2, modulator level high with a short envelope for a plucked attack, a touch of feedback for growl.
- Bell - non-integer ratio such as 3.5, modulator with an instant attack and long decay.
- FM drums - inharmonic ratios, very short envelopes, a pitch envelope for kicks and toms.
Modern extras
DX7 V adds features such as extra waveforms beyond sine, a modulation matrix, effects and sequencing tools. Use them - but learn the classic architecture first, because it is what every FM synth is built on.
Do this now
- Load an init voice in DX7 V and build a two-operator patch: one carrier, one modulator. Sweep the modulator's level and ratio.
- Build an electric piano and play a chord progression with it.
- Build a metallic FM hi-hat and use it in a drum pattern.