■YAMAHA DX7 (1983) Digital Programmable Algorithm Synthesizer
The DX7 was the first affordable synthesizer implementing FM synthesis designed by John Chowning: the digital revolution changed the sound forever. In following years it is revamped to DX7 Mk2.
■VOICES synthesizer 16 voices polyphony based on FM synthesis - the DAC BA9221 works at 12 bits.
IC YM21280 generates 6 syncable sinewave oscillators or operator each with individual volume settings and pitch detune (EG is generated by IC YM 21290)
■SYNTHESIS 6 sinewave operators organized as algorithms, assigned as carrier or modulator, linked between them on different pathways interacting on their harmonic contents depending on the variable feedback strength.
- carrier; defines the amplitude and the spectral frequency
- modulator: sets the sound timbre and the relative harmonic contents.
■DX7 features 32 algorithms combinations with frequency ratio or fixed frequency: the output is fed back to its input with 7 different levels feedback, as general rule, high values feedback results in richer harmonic contents.
■LFO up to 2 modulators (shapes: sine, triangle, saw up/down, square and sample & hold) with adjustable start delay and sync retrigger:
- PMD modulates pitch
- AMD processes the amplitude.
■ENVELOPE the IC YM2819 generates 7 EGs:
- 1 EG pitch: 4-segments structure + 4 time levels.
- 1 EG for each operators: 4-segments structure + 4 time levels
The Scaling Level is a very precise key follower with 4 linear / exponential curves
■MEMORY - 32 RAM patches.
Internal RAM is doubled if a cartridge mode RAM1 is present, also many third part cartridge for more banks including EMW DX70, Interlock TurboDX1, FORAT MAM 2000, Steinberg Monsterram, Yamaha Sound collection voice. The backup memory works with a CR-2032 lithium battery soldered to the mainboard - be aware that there is no ROM factory recall, so it is necessary to use Midi exclusives data for this job.