YAMAHA OPL3 IC Chip Series

 

The OPL (Operator Type-L) are a series of sound chips for low budget synthesizers and mainly PC gaming soundcards based on FM synthesis.

 

The OPL version "3" is the third version fully compatible with previous classic OPL 2 aka IC YM3812 mainly found on commercial success ADLIB soundcard featuring some technical upgrades and double polyphony

IC CHIP the original OPL3 YMF262 LSI micro chip produced by Yamaha Japan and developed in several formats and versions.

Most common OPL3 chips are:
- YMF262 / YMF262S / YMF262m (Soundblaster 16 + some AWE)
- YMF289 / 298B low power variant (Soundblaster 16 e.g CT-2910)
- YMF719 OPL3-SA / SAX (quite same YMF715 and YMF701).

The last OPL was the fourth version OPL4 YMF278 which is basically an OPL3 + an internal wavetable similar to SY/TG AWM synthesizers.
When wavetable soundcards come up, the genuine OPL FM began to disappear, first replaced by CREATIVE-EMU emulation then totally considered as obsolete.

 

 

 

VOICE compared to previous OPL2, the OPL3 IC doubles polyphony from 9 to 18 voices that now can be also hard-panned to extreme left / right.
The OPL3 is based on FM SYNTHESIS (check out Yamaha DX7 for more information) and generates 36 Operators or digital oscillators that can be allocated into 4 ways (voice mode) to create sounds and musics:

 

Voice mode	Basic melody (a voice is composed by 2OP)	Advanced melody (a voice is composed by 4OP)	Special Drum mode
1	18	-	-
2	15	-	5
3	6	6	-
4	3	6	5

 

ALGORITHMS operators organized as algorithms assigned as carrier or modulator linked between them on different pathways interacting on their harmonic contents depending on the variable feedback strength. The OPL3 offers 2 X algorithms in 2OP mode + 4 X in 4OP mode.
Algorithm list

WAVEFORMS unlike traditional 6 OP structure from Yamaha DX7 which is based on a single sinewave operators (pic1, the OPL3 operators is able to generate also 7 extra sinewave harmonic variations waveforms (reading the loopkup tables with different speeds) like budget 4 OP module Yamaha TX81Z but some shapes are different.

 

 

PERCUSSION MODE special 6 OP drum mode generates 5 percussion sounds sharing the operators resources in the following mode:
- kick (1 OP)
- snare (1 OP)
- Tom (1O P)
- Cymbal (1 OP) cannot be tuned
- hihat ( 1OP) cannot be tuned.

 

LFO up to 2 modulators for each OP:
- LFO amplitude frequency fixed at 3,7 Hz
- LFO pitch frequency fixed at 6,1 Hz.
A kind of master LFO can be set for whole voices, in this case it features a Depth adjustment.

 

ENVELOPE 4 EGs: each OP features 1 amplitude EG (4-segments), in addition each OP has individual Mix volume. Very simple Key tracking with 3 fixed levels.

OPL UTILITY and GAMES many games from the nineties include soundtracks made with ADLIB OPL soundcards: the sound was typical from the post-sid era and some true gems were composed like Origin Ultima 6 / 7 soundtrack or Dune by Exxos which I even prefer compared to external wavetable Midi module like Roland MT32.
OK there's not only OPL gaming but also some very professional and outstanding software developed: trackers, synthesizers, sound editors and much more! some are very interesting materials for musical purpose. Most of these applications run only on pure MS-DOS, consequently an ISA soundcard is far the best choice unless you want to get crazy with drivers - also remember that ISA is no longer supported from Windows XP on.

Ultima 6 (ORIGIN) OPL3
DUNE (EXXOS) OPL3
Adlib tracker popcorn

 

 

VIDEO CLIP SELECTION OPL3 with Yamaha TX7 typical PC ADLIB music AdLib tracker