The TG77 is a hybrid synthesizer that combines 6-operator FM and AWM2 synthesis for some very expansive sound creation capabilities. Yamaha refers to the FM synthesis as AFM, meaning Advanced Frequency Modulation. The "advanced" part comes from the availability of extra oscillator waveforms - 16 in all, with 45 different algorithms available. Each of the two engines is 16-note polyphonic, allowing for up to 32 notes of polyphony depending on how sounds are structured.
The TG77 is a rackmount version of the Yamaha SY77. It lacks a sequencer, but is otherwise nearly identical. The Yamaha TG55 is an AFM-only rackmount tone generator from around the same time and uses the same button style.
It has PCM waveform and data card slots, and expansion cards typically come in pairs. View the available expansion cards.
The display back light commonly burns out on these units. It can be replaced, and the screen is usable without it, but it is harder to read without a working backlight.
Yamaha LSI Chips used in the TG-77:
YM3029 (x3) - DAC. (Four channels per DAC).
Year Released: 1990
Polyphony: 32 notes
Multitimbral: 16 parts
Preset Patches: 128
User Patches: 64
Preset Performances: 16
User Performances: 16
ROM: 4MB (112 waveforms)
Effects: 2 digital effects processors
Screen: 240 x 64 pixel backlit LCD
Outputs: 12 x 1/4 inch (2x stereo pair, 8x individual)
Power Consumption: 28 watts
Dimensions: 490 mm x 390 mm x 132 mm
Weight: 8 kg
This is a 3-space rack unit.
Yamaha TG77 1990 ($595)
Yamaha SY/TG77 Drums 1 Sound Card Set ($149.99)