Tone-Scale Generators
© 2002, Russell Borogove
Edge2: A Tone-Scale Generator
Inputs/Outputs: no in, 8 out
Parameters:
Parameter Name | Description | Range |
Keynote | Root note of scale | 12 tones, C to B# |
Octave | Base octave of scale | 1-8, C4 (middle C) = ~262 Hz |
Fine Tune | Fine tuning of root note | -100 cents (-1 semitone) to +100 cents (+1 semitone) |
Scale Family | Select group of musical scales | Builtin set plus zero or more Scala sets |
Scale Mode | Mode for output scale | Major, Minor, etc. |
Scale Offset | Steps skipped before output series, allows cascading multiple Edge2s | 0-176 |
Nominal Waveform | Oscillator 1 waveform | Sine, Square, Triangle, Sawtooth, Cusp, Moist, Tuft, Plimsoll, Tundra, Demagogue, Instar, Blastulae, Flummox, Hellacious, Boondoggle, Zinc |
Nominal Level | Oscillator 1 mix level | 0.0-1.0 |
Even Bonus Level | Oscillator 2 (even harmonics) mix level | 0.0-1.0 |
Odd Bonus Level | Oscillator 3 (odd harmonics) mix level | 0.0-1.0 |
Detune Nominal | Oscillator 1 detune | -100 cents (-1 semitone) to +100 cents (+1 semitone) |
Detune Even | Oscillator 2 detune | -100 cents (-1 semitone) to +100 cents (+1 semitone) |
Detune Odd | Oscillator 3 detune | -100 cents (-1 semitone) to +100 cents (+1 semitone) |
Gain | Overall mix level | 0.0-1.0 |
General Description
Edge2 is a 3-oscillator by 8-voice additive synthesis tone generator, producing a scale of eight tones, one per output, simultaneously. By itself it doesn't do a lot, but in conjunction with Mulch's matrix mixers or other sequencing/mixing contraptions such as Pegger II, it can be fairly useful.
The root-tone, base octave, and fine tune controls determine the pitch of the root note, and thus the key of the scale. The particular scale-mode to be output is selected by Scale Family and Scale Mode. Scale Offset, if nonzero, starts the output channels with the Nth step of the scale rather than the root. If you put two Edge2 side by side, one with an offset of 0, the other with an offset of 8, for example, the two together act like one Edge2 with 16 outputs (aka DoubleEdge2).
Several scales are built in to the plugin, but any desired scale/mode/tuning can be activated by putting an appropriate Scala file in the same directory as the Edge2 plugin. Scala is a powerful tool for experimenting with musical tunings, and the Scala web site contains an enormous archive of scales to choose from. When Edge2 is started up, it will scan for Scala files (telling you the name of the path it is searching, so you can make sure the files are in the right place) and collect all the Scala files it finds. They will appear in groups of up to 100 in no particular order; you may have to grovel through the "Scale Family" and "Scale Mode" controls for a while to find what you're looking for if you simply drop thousands of .scl files on it. This facility has been only sketchily tested. Using thousands of Scala files should theoretically work, but it may add substantially to Edge2's startup time and tie up lots of memory. Try this at your own risk.
Each output channel is voiced with three wavetable oscillators. One provides the traditional analog waves as well as 12 modified Borogove Nominal Synthesis waveforms. The other two provide a series of even and odd harmonics respectively. The three oscillators can be mixed and detuned to give a pleasing or not-so-pleasing timbre.
DoubleEdge2 is exactly the same, but comes with 16 outputs instead of 8, playing 16 notes of a scale.
Development Notes, Known Bugs, and Limitations:
I have not tested Edge2 with any VST host other than Ross Bencina's AudioMulch.
When the Scale Family control is changed, the Scale Mode control should automatically update itself to show the name of a scale in the new family. If it does not, simply adjust the Scale Mode control slightly and the problem should correct itself. This problem should not occur in Mulch, but probably will occur in Plogue Bidule, and may occur in other VST hosts.
Unlike the original Edge, you can adjust the timbral controls while running with no impact on performance. This and the Scala file support are the only essential differences from Edge.
Edge2 Revision History:
v0.5 - Initial Release.
v0.6 - Fixed high-pitch crash, extended scale mode limit
- Edge2 would crash while trying to play a ridiculously
high-pitched tone. Pitches are now octave-shifted until
they're under 20KHz.
- Scala data beyond 16 scale steps was ignored, and scale
offset was limited to 8 steps. Now scales of up to 184
steps are allowed. You'll need 23 instances of Edge2, each
with a different scale offset, to fill that out, of course.
v0.6 Double - Double your edginess!
- DoubleEdge2 is a version with 16 scale-steps instead of 8. Go wild.
v0.61 - Oops.
- DoubleEdge2 now looks for Scala files in the right place. My bad.
Terms:
Edge2 is free to take and use as you will. If you like it, or if you don't like it, please drop me an e-mail telling me so.
If you make music with it, and make that music available to others, tell me that the music is available. That means if you sell CDs of your stuff, you tell me how to buy a CD; if you let people download MP3s for free, tell me where I can do the same.
This software may contain bugs, errors and other problems that could cause system or other failures and data loss. Consequently, it is provided to you as-is, and I disclaim any warranty or liability obligations of any kind.
If you wish to redistribute the software, please distribute it in its packaged .zip-file form, or another archive format, along with this documentation.
You have the right to decompile, disassemble, reverse-engineer, and modify the software for personal research and for fair-use purposes such as adapting the software for interoperation with other systems. I don't believe that I can legally take this right away from you, though some large companies might try. If you'd like access to the source code, it's possible we can work something out; drop me a line.
You do not have the right to reverse-engineer or modify the program in order to violate my copyright on the software, e.g. to distribute a version with "the serial numbers filed off".
Legals:
Edge, Edge2, and DoubleEdge2 are copyright © 2001-2002 Russell Borogove.
http://www.tinygod.com/
VST™ is a trademark of Steinberg Soft- und Hardware GmbH.
http://www.steinberg.net/
AudioMulch is copyright ©1997-2002 Ross Bencina
http://www.audiomulch.com/