YAMAHA DX7 (1983)

The first real commercial release of Yamaha's FM synthesis designed by John Chowning.

The dx7 is now pretty old and still considered as pretty tough to understand. Is it still worth a buy today? let's check this out!

KEYBOARD dark brown case metal (bullet-proof) weight approx.15 Kg
The synthesizer has 61 keys with Velocity range 0-99 (not really 127) featuring also Aftertouch and editable Velocity Curves.
On the left side (pic) there are two assignable wheels for Pitch and Modulation (value ranges are adjustable for both) and below a headphones connector plus a a 1.5mm Yamaha Breath controller Input.
Main panel: LCD16 x 2 lines with no backlight, two sliders for Volume gain / Value edit and 42 membrane buttons for programming functions and numeric patches change.

The back panel (pic) has these connections: one Mono jack out for Volume, a the Midi I/O, two footswitch inputs for Sustain and Portamento and finally two Foot controller Inputs for Volume and Modulation.

Power supply is internal. Exists in both 110V and 220V.

VOICES 8 bit Main core CPU Hitachi HD63A03X that manages 16 FM digital voices.
YM2128 generates six syncable digital oscillators (sinus waveform) called "Operators" and a single OP has individual volume settings and Pitch Detune-Coarse. These OPs can be chained into 32 different combinations called "Algorithms" with Frequency ratio or Fixed frequency: the output will be fed back to its input with seven different levels called "Feedback" and, as a general rule, high values Feedback results high Harmonic contents (for more info check out "FM synthesis" below).

FM SOUND typical 80' FM mellows Rhodes abused in tons of mellow hit records or typical digital bell or even some '80 electro bassline - DX7 can do this and much more like crystal sounds with lush strings or even industrial dark pounding noises. FM... HOW? There are six operators with Sine waves organized as "Algorithms" depending on the function of "Carrier" or "Modulator" linked between them on different ways interacting on harmonic contents, depending on the "Strength" called "Feedback" . The Carrier sets the Amplitude and the Spectral Frequency while the Modulator mainly sets the sound timbre and its harmonic contents. FM TODAY FM principle is still in the synthesizer history even decades after, "living" in some in machine like Yamaha Sy-99, the groovebox Dx-200, the powerful Fs1R or even computer plugins. Nevertheless the DX7 still shines for its sounds maybe for the raw dynamic at 13 bits resolution with no antialiasing. SPECIAL TEST: YAMAHA DX7 VS DX7 MK2 HERE!

LFO two digital Low Frequency Oscillators with Frequency and adjustable Start Delay: "PMD" modulates Pitch and "AMD" for Amplitude.
Both LFO have six variable waveforms Sinusoidal / Triangle / Saw UP-DOWN / Square / Sample & Hold .
The special "LFO sync" function allows to continue the modulation effect between notes or retriggers the modulation from beginning.

EDIT All functions are editable with the famous "Data Entry" slider on tiny display, rather Spartan! Fortunately there are lots of computer editors available.

MEMORY 32 patch RAM backup with soldered CR-2032 lithium battery plus 32 extra sounds on external cartridge data slot- of course you can still dump your data by Midi Sysex exclusives.

ENVELOPE the YM2819 generates a total of 7 envelopes: one Eg pitch + one EG per Operators (six): all EGs have 4 segments and 4 different time levels. Another important function is the Scaling Level, a very precise key follower with 4 linear or exponential curves and Depth. FX none NB: in later 4-OP FM engines Yamaha used some kind of pseudo reverbs tricks like in TX-81z.

OP6 DX FAMILY After one year Yamaha released the super deluxe version Dx1 that later became the "cheaper" DX-5.
There' s also an expander module called Tx-7 and the huge TX-816 a pretyt impressive rack modular version, while The Tx-802 is a DX7 II (mk2) rackmount versions.
Below a little DX Sum-up:

"GREY MATTER E!" BOARD EXPANSION Standard Dx7 mk1 is monotimbral with some minor flaws like Velocity on keyboard that Yamaha corrected later with "DX7 mkII" featuring clearer DAC at 16 bits resolution. Nevertheless some people still prefer the "mk1 brownie" fatter and dirtier sound, so If you' re in love with this model, there are ways to fix some of the irritating original defects by hardware modifications, In fact, third party companies build cutom upgrades and one the best board is the "E!" from Grey Matter Response. Grey matter CARD it is not easy to find and requires a Dx7 with one the latest OS (only upgradable by EPROM) and tough to install requiring some skills on soldering and even cutting / re-routing circuit tracks (check out E! card INSTALL pictures gallery). -DOWNLOAD Dx7 E grey matter PDF manual

Upgraded Dx7 E! is multitimbral with ten time more RAM slots and some optional sound ROM banks EPROM that were sold a part. Monophonic Mode with up to eight voices Stack and adjustable Random Detune (variable range set) a user-friendly TX programmability, Midi out Channel, controller Remap and much more !

Official 1983 demo part1 part2 part3

The Zak original videogame theme made in 1987 by Matthew Alan Kane with DX7 and Juno106. Thanks Matthew! Random FM electronic sequence

 

- powerful FM sound
- Concept
-pure synth history

- keys dynamic
- weight
- 1 slider edit may sounds a bit awkward.

PERSONAL OPINION:

We're here in front of the history! Massive sound, really raw-powerful.

They are gone cheap these days: second hand price 200 /300 euro for "normal" 400 + for E! version