Algorithms; Triggering Principles - Yamaha YM3806 Programmer's Manual

Table of Contents

OPQ Programmer's Guide V 1.1

•

In all algorithms, Op0 is always a modulator, never a carrier. It is also the only

operator which can use feedback. The feedback possibility is indicated with the

feeback loop around Op0 in the algorithm picture on next page.

3.2 Algorithms

There are 8 algorithms to select from. The algorithms are presented in the following

picture.

The operator triggering scheme is quite different from OPL3. With triggering I mean turning

operators on and off with their corresponding key-on bit. The main difference to OPL3 is

that the triggering is not done per channel, it is done per operator. This means that even

same channel's operators can be turned on or off at different times. Turning operator on

starts its envelope's attack phase and turning it off starts the release phase. This gives

quite a few new possibilities in sound design. I have not noticed that PSR-70 firmware

would make use of this possibility.

There are some limitations, though. As mentioned, Op3 acts as a master operator: it must

always be triggered on, otherwise channel's other operators won't trigger at all. Similarly,

when Op3 is triggered off, all other operators will be triggered off at the same time. But

while Op3 is on, you can freely trigger other three operators on and off, even several

times, if you want.

Table of Contents