The Yamaha TX81Z is an 8-note, 4-operator FM tone generator that fits in a single rack space. It has 128 internal ROM voices and 32 user-programmable RAM voices. You can also load voices from a DX21, DX27, or DX100 to expand your sound library quickly. Like the Yamaha FB-01 tone generator, the TX81Z is capable of producing eight different voices simultaneously. You can store any combination of the ROM and RAM voices in one of the 24 Performance Memories for instant recall. All of the voice parameters are programmable from the front panel, with a choice of eight different wave shapes for each operator.
Performance Mode and Performance Edit
In Performance mode you can select any of the 24 Performance Memories. The Performance Memories contain the information that determines which voices will play, how they are tuned, what their volume is going to be, and other related parameters. All of these parameters are fully editable in the Performance Edit mode.
In Performance Edit you first determine how many notes will be assigned to each voice, then you choose the voices that will play. This is called an instrument. Any combination is possible, from a simple dual instrument arrangement (with four notes per voice) to eight separate instruments (with one note per voice). Each instrument can be set to receive on a separate MIDI channel. This is very useful if you are using the TX81Z with a sequencer or a controller that will send multiple MIDI channels. There are also two assign modes that determine how the instruments will respond to incoming MIDI data. In Normal mode, each instrument plays on its assigned channel with its assigned polyphony. In Alternate mode, incoming notes that match the basic MIDI reception channel cycle through the assigned instruments. For instance, if you have eight instruments assigned to a performance, each time you play a note it will play a different instrument. If you put eight slight variations of the same voice in a performance, you can create a nice ensemble effect with the Alternate mode.
If you don't have a keyboard that can simultaneously output multiple MIDI channels, you can create keyboard splits by assigning different high/low key limits for each instrument.
The relative volume and output assignment of each instrument is programmable too. An instrument can be assigned to either one of the TX81Z's stereo outputs or to both outputs. Each instrument can be individually tuned. If you need to transpose an instrument in a Performance Memory, you can use the note shift feature to move it in semitones over a four octave range. For smaller detunings, there is a Detune feature for each instrument. This is particularly good for creating chorus effects when used as a "dual detune."
The TX81Z has two independent LFOs and a vibrato mode for complex modulation effects. The two LFOs are for instruments that need amplitude modulation or both amplitude and pitch modulation. If you need to have only pitch modulation, you can select the vibrato setting for an instrument. In the vibrato mode each instrument adopts the LFO setting from the assigned voice. This means that you can have up to eight independent LFOs in a performance. One of the 11 micro tune scales can be selected for a performance group. These allow you to use . tunings other than standard equal tempered tuning. Instruments in a Performance Memory can either be assigned to the equal tempered scale or to the selected micro tune scale. You may also add one of the TX81Z's three effects-delay, pan, or single note chord. All of the performance parameters can be stored to one of the 24 Performance Memories. Like voices, performances can be named. The name is displayed at the top of the LCD window for quick identification whenever a performance is selected.
In addition to the Performance Edit mode, there is a Performance Utility mode. The performance utilities help you create and edit your performances, but are not saved with them. This is where you initialize a performance. There are several preset initialization types to choose from (single, dual, split, poly 4, mono 8), so that you can find the one that most closely suits your needs. There is also a voice edit feature, so that you may edit a voice in a performance without going to the Single Edit mode (where voice editing normally takes place).
Play Single and Single Edit
The Play Single mode is where you select individual RAM and ROM voices for playing and editing. Every voice plays with full 8-note polyphony, without any of the effects or added features in Performance mode. When you find a voice you want to edit you enter the Single Edit mode to change it.
The TX81Z uses FM synthesis to produce sound, so the programmable parameters in Single Edit are similar to the other DX/TX FM synthesizers. A multiple page approach is used in Single Edit. For instance, if you want to edit thespeed of the LFO, you must first go to the "Edit LFO?" display. When you press the YES button, you will enter the LFO editing page and the associated parameters will appear for you to edit. All of the parameters in the Single Edit mode are stored with each voice.
The first parameter you can edit when you enter Single Edit is the algorithm. There are eight algorithms, and a graphic representation of each is given in the LCD as you scroll through them. There is also a pullout menu underneath the TX81Z that shows the algorithms and lists all of the available editing parameters.
In the LFO page you can program the wave and speed of the LFO, determine the delay before the LFO enters, and turn LFO sync ON or OFF. The initial amount of pitch and amplitude modulation can be set here as well. The Sensitivity page follows, allowing you to determine the pitch modulation, amplitude modulation, EG bias, and key velocity sensitivity for the voice.
The Edit Frequency page is where you change the coarse and fine frequency settings of all the operators. For the first time in a 4-operator instrument, fixed frequencies are available. Also for the first time, eight different waveshapes are available for each operator. In addition to sine waves, there are seven waveshapes that have more complex harmonic structures. This not only means that you can create sophisticated timbres using fewer oper· ators, it also offers a relatively unexplored area for creating unique sounds. The EG page includes the same five-stage envelope that the DXlOO uses. Four rates and one level are programmable for each operator. There is also an EG Shift parameter that has been added to the TX81Z. This feature "compresses" the EG range. Normally, the EG changes the operator output level from - 96dB (no sound) to OdB (maximum). You can use EG Shift to change the range from - 48dB to OdB, - 24dB to OdB, or - 12dB to OdB. If you apply this to a modulator, you can create a more defined attack and quickly make large timbre changes. Other voice parameters include feedback, operator detune, operator output level, and operator scaling. Both rate and level scaling are available for each operator.
You can determine how each voice will respond to MIDI Controller information in theFunction page. Pitch and amplitude modulation may be controlled by a foot controller, modulation wheel, or breath controller. A foot controller can also be assigned to change volume, and the breath controller can control EG bias (for changing volume and timbre) and pitch bias (for directly controlling pitch). All control parameters can be set over a wide range (0-99), so different amounts of each effect can be controlled from a single controller. In the Single Utility mode, there is a feature that allows all of the breath control assignments to respond to aftertouch messages, in case you don't want to use a breath controller.
The Function page is where you also select edit mode assignments (poly, mono), pitch bend range, portamento time, portamento type (full time, fingered), and voice names. The voice transposition feature lets you transpose the voice over a four-octave range, and there is a reverb feature that automatically affects all of the operator EG release rates to create a reverb effect. This effect is adjustable in seven steps to simulate different reverb times.
Parameters that aren't programmable as part of a voice-master tune, memory protect on/ off, voice initialize, and edit recall functions-are accessed in the Single Utility section of the TX81Z. This is where you will also find the MIDI control parameters, cassette parameters, the three effect setups, and two userprogrammable micro tune tables. Parameters on the MIDI Control page determine how the voices in the TX81Z will respond to incoming MIDI messages. The basic MIDI transmit and receive channels can be set. You may filter out control change, pitch bend, and system exclusive information if needed. There is also a feature that lets you choose a global MIDI channel for pitch bend and control change commands. This means that you can have all of the instruments in a performance on different MIDI channels, and add modulation or pitch bend effects to all of them simultaneously by sending messages over the global channel you have selected.
You can initiate MIDI system exclusive bulk data dumps from the MIDI Control page. This is useful if you want to send data to another TX81Z or a storage device, like the Yamaha MDFI or a computer. Voice data, Performance data, and Setup data can be sent separately. There is a menu for the Setup data that allows you to individually send system information (your MIDI setups), the current settings of your program change table, the settings for the three effects, or the data for the two userprogrammable micro tuning tables.
The MIDI page includes the Program Change Table. The table determines how the TXBIZ will react to program change commands that appear at its MIDI input. You may assign any of the internal RAM or ROM voices or any of the 24 performances to be selected by a single program change command. You can initialize and edit the Program Change Table. There is also a Program Change select mode that gives you the option of filtering out incoming MIDI program change messages, changing all instruments in a performance from a common program change (on the basic MIDI receive channel), or letting each instrument in a performance receive program change commands individually on their own MIDI channel.
Finally, there is a Key Number mode that determines how the TX81Z reacts to incoming MIDI Note On commands. The TX81Z can receive all incoming notes, just odd note numbers, or just even note numbers. If you play two TX81Zs simultaneously, and set one of them to receive only even note numbers and the other to receive only odd note numbers, you can have what amounts to a single 16-note TX81Z capable of playing up to 16 individual instruments. The Cassette Control page gives you the ability to save your work to a standard audio cassette. You can save, verify or load 32 voices, 24 performances, or entire setups (with all of the setup options available in the MIDI Control page). You can also load just one voice or performance if necessary.
The TX81Z includes three effects-delay, pan, chord-that can be edited in Single Utility. The delay time, feedback amount, effect level, and pitch shift amount are all programmable for the delay. Although this effect sounds like a digital delay, it actually creates the delay effect by retriggering the voice at a lower velocity. This creates an extremely clean-sounding delay. The pitch shift feature can be set in semitone increments so that the voice will be transposed every time it is echoed.
The panning effect moves the voice between output I and output II. Panning can be controlled by the LFO, Note On velocity, or note number (the voice pans as you move from one end of the keyboard to the other}. To further enhance the effect, pan direction and pan depth are programmable. Chord, the third effect, lets you set up a chord (up to four notes) and assign it to any MIDI note. 12 different chords can be defined and assigned to different MIDI notes.
Finally, the two user-programmable micro tune scales can be initialized and edited in the Single Utility section. On many electronic instruments only standard equal tempered tuning is available. Most acoustic instruments don't have this limitation. For instance, when string players perform as a section, they often deviate from strict equal tempered tuning. You can use the micro tuning scales to imitate these types of tunings or to experiment with new tunings. There are 11 preset micro tune scales that can be used with a performance or as a starting point for building the two user micro tune scales. Any new scales you create can be stored and used with a performance as well.