the OPL FM editor is divided into 7 tabs:
- FM: for controlling the basic parameters of FM sound source.
- Macros (FM): for macros controlling algorithm and feedback.
- Macros (OP1): for macros controlling FM parameters of operator 1.
- Macros (OP2): for macros controlling FM parameters of operator 2.
- Macros (OP3): for macros controlling FM parameters of operator 3 (only when 4-op flag is set and only on OPL3!).
- Macros (OP4): for macros controlling FM parameters of operator 4 (only when 4-op flag is set and only on OPL3!).
- Macros: for other macros (volume/arp/pitch/pan).
the OPL synthesizers are nominally two-operator (OPL3 supports 4-operator mode on up to six channels), meaning it takes two oscillators to produce a single sound.
these apply to the instrument as a whole:
-
Algorithm (ALG): determines how operators are connected to each other (0-1 range and OPL1 and OPL2; 0-3 range on OPL3 4op mode).
- left-click pops up a small "operators changes with volume?" dialog where each operator can be toggled to scale with volume level.
- right-click to switch to a preview display of the waveform generated on a new note:
- left-click restarts the preview.
- middle-click pauses and unpauses the preview.
- right-click returns to algorithm view.
-
Feedback (FB): determines how many times operator 1 returns its output to itself (0 to 7).
-
4-op: enables 4-operator FM instrument editor mode (only on OPL3).
-
Drums: enables OPL drum mode editor.
these apply to each operator:
- the crossed-arrows button can be dragged to rearrange operators.
- Amplitude Modulation (AM): makes the operator affected by LFO tremolo.
- Sustain flag (SUS): when enabled, the envelope pauses ("sustains") once it reaches the Sustain Level and does not proceed to the release phase until note off.
- Attack Rate (AR): determines the rising time for the sound. the bigger the value, the faster the attack (0 to 15).
- Decay Rate (DR): determines the diminishing time for the sound. the higher the value, the shorter the decay. it's the initial amplitude decay rate (0 to 15).
- Sustain Level (SL): determines the point at which the sound ceases to decay and changes to a sound having a constant level. the sustain level is expressed as a fraction of the maximum level (0 to 15).
- Release Rate (RR): determines the rate at which the sound disappears after note off. the higher the value, the shorter the release (0 to 15).
- Total Level (TL): represents the envelope’s highest amplitude, with 0 being the largest and 63 (decimal) the smallest. a change of one unit is about 0.75 dB.
- Key Scale Level (KSL): also known as "Level Scale". determines the degree to which the amplitude decreases according to the pitch.
- Key Scale Rate (KSR): also known as "Rate Scale". determines the degree to which the envelope execution speed increases according to the pitch.
- Frequency Multiplier (MULT): sets the coarse pitch offset in relation to the note (0 to 15). the values follow the harmonic scale. for example, 0 is -1 octave, 1 is 0 octaves, 2 is 1 octave, 3 is 1 octave 7 semitones, and so on.
- note that values 11, 13 and 14 behave as 10, 12 and 12 respectively.
- Waveform Select (WS): changes the waveform of the operator (OPL2 and OPL3 only, 0-3 range on OPL2 and 0-7 on OPL3).
- Vibrato (VIB): makes the operator affected by LFO vibrato.
these macros allow you to control several parameters of FM per tick.
all parameters are listed above.
all parameters are listed above.
- Volume: volume sequence.
- Arpeggio: pitch sequence.
- Panning: enables output on left/right/rear channels. OPL3 only.
- Pitch: fine pitch.
- Relative: when enabled, pitch changes are relative to the current pitch.
- Phase Reset: restarts all operators and resets the waveform to its start.
this is similar to the OPL instrument editor, but sets the parameters of snare, tom, top and hi-hat directly once a drums instrument is activated.