Yamaha Tx81z Multi Timbral FM tone generator (1987)
A budget rack featuring a FM variation of traditional DX 6OP. Budget spin-off from the famous DX7 FM synthesis, however the tx81z has some interesting technical improvement.
RACK a single black unit expander (3.4 kg weight). The front panel has an headphones out and 11 buttons for all the programming directly on a 2 * 16 lines LCD with active matrix; a bit hard to edit and no always so obvious to understand. Back panel has the following connections: double pairs of audio outputs (the second one has special audio routing patch in Performance mode), the tape interface for storage backup-restore and a midi I/O
Power supply is internal and some latest (or international) versions have a switch between 110v and 220V. CHECK voltage ANYWAY!!
VOICE CPU is a HD63803XP branded Hitachi manages up to eight digital voices. The traditional DX synthesis was based on a 6 operators system with just pure Sine waveforms and 32 combinations algorithms. The internal TX81Z chip YM2414B has only 4 Op and 8 combinations- on the other hand this YM system boasts 8 different waveforms: the standard Sinusoidal + 7 computer-generated harmonics variations with partials and fundamentals fixed settings, and like DX series, each can be either Carrier or Modulator.
PERFORMANCE up to 8 parts each with independent settings including Volume, Midi Channel, Detuning, Effects (see below) and Pan position.
Performance part has also some factory playmode presets like 2 * 4 voices stacks or 8 * 1 monos: great for some thundering Lately bass sound! A special MONO play mode is available with Portamento and Glide time adjust. The processor has some limits and cannot layer some particular algorithm combinations, also keep in mind that the Midi response has some freezes with data flows (depends also on the OS EPROM official from 1.0 to 1.6).
LFO two modulators (frequency range from 0.007Hz to 50Hz) with variable waveforms including Saw, Square, Triangle and Sample & Hold. LFO modulate Amplitude- Pitch and feature some extra parameters like Delay Start or note Sync (modulation re-rigger).
ENVELOPE four EG in total. Each Operator has a single Amplitude EG (4-segments) + a general shift, plus a very simple Key Tracking Scale less complicated and effective than the one on the DX.
EFFECTS not a real DSP but faked simulated by Midi notes tricks reducing the (tiny) polyphony.
Three preset effects:
- Delay with pitch shift and adjustable Feedback.
- Pan moving: stereophonic path with follow velocity or LFO from left to right or vice versa.
- Chords with a maximum of 4 notes.
MEMORY holds 128 ROM presets+ 32 ram users+ 24 RAM Performances.. No external storage but full Sysex dump and edit by Midi or tape dump; note that MIDI sysex strings are NOT compatible with 6OP DX line.
WARNING! Remember to do backups before any replacement attempt.
lithium battery soldered 3V Cr-2032
MICROTUNE the 4 OP structures has 13 available tables: 11 ROM preset + 2 users for non-standard intonation including Equal, pure, major-minor, Vallotti and Werckmeister.
if you have some cool recordings, consider sharing them. Thanks