Yamaha DX7 - Variants

Variants

The original DX7 featured a brown case with plastic membrane film buttons, and was produced from 1983 to 1986. Three improved DX7 II models were released between 1987 and 1989, all of which featured updated internal circuitry with improved sound quality (from 12-bit to 16-bit), and a more aesthetically pleasing hard-plastic case with conventional buttons and larger sliders:

-- DX7 IID - increased the internal patch memory and allowed bi-timbrality

-- DX7 IIFD - added floppy disk drive (3.5" 720K DS/DD)

-- DX7S - same essential functionality of the original DX7 (and in that sense its true successor), but with the improved 16-bit sound engine of the "II" models, and double the internal memory (64 patches vs. 32). Other notable improvements include a new Performance mode, Unison mode (for fatter analog-type sounds), and more streamlined editing due to direct access to operators via front panel buttons.

Third-party support for the DX7 also flourished in the 1980s, including Grey Matter Response's E! expansion board, which added sequencer functions to the DX7 II keyboard, increased patch memory, and featured a vastly improved MIDI implementation for the original DX7. DX7 IIs were able to transmit and receive on any one of 16 MIDI channels at a time.

The upgrade to 16-bit digital-to-analog converters helped to solve one of the original DX7's shortcomings - noisy output. The instrument's 12-bit DAC's generated a fair amount of hiss, and some users resorted to using a noise gate in the signal path to quiet the unit.

Yamaha wisely designed the DX7 II series such that voices produced on the original DX7 were compatible with the new models. This allowed users to enjoy the benefit of the increased resolution and fidelity of the new 16-bit system with existing DX7 patches. This meant that the DX7 II maintained backward compatibility with the vast base of existing DX7 sounds, which amounted to a major selling point for the new units.

In 1988, in celebration of the company's 100-year anniversary, Yamaha released the DX7 II Centennial. It was a DX7 II FD that featured a silver case, gold painted buttons and sliders, and 76 glow-in-the-dark keys. Only 100 were produced, and they were offered at $3995 USD.