Wiard Mini-Wave FAQ

[Grant Richter]

I apologize to anyone offended by the bandwidth use or commercial content.
There is enough generally useful information in here I thought it would be
OK to post on synth-DIY. The software nature of the product allows
considerable DIY fun on an inexpensive common platform.

I am proceeding to get the Frac-Rac and kit version of the Mini-Wave (1202)
ready for production. This is a general purpose non-linear function
generator in a Frac_Rac module format. The panels are drilled with 1/4"
holes for 3.5mm connectors (ARP, Aries, Blacet, Buchla, Digisound, Doepfer,
PAIA, Roland 100, Wiard) but I left enough room so you can open them up to
5/16" for banana connectors (Serge, Fenix, Modcan) or 3/8" holes for 1/4"
connectors (Moog 900, MOTM, Roland 700). I am going to try to keep this for
all the 1200 series.

A. What is it?

This is general purpose voltage input, voltage output device. The input gain
and offset can easily be changed to deal with either +/- 5 volt sawtooths or
0-10 volt sawtooths (Arp 2600) or 0-5 volt sawtooths or +/- 2.5 volt
sawtooths. It will do wavetable playback, voltage quantization (Footnote A)
and non-linear synthesis (so called timbre modulators Footnote B).

When an ascending ramp sawtooth is input it functions like a wavetable
playback unit. A descending ramp plays the waveform in reverse. A triangle
plays it once forward then in reverse an octave up. An envelope input allows
a voltage controlled sweep of 16 consecutive waves in the wavetable
with a 0-10 volt input, but you can change a resistor value to make it 0-5
volt input.

B. How do I program it?

The wavetables are programmed on two custom Windows32 programs, Wave256 is
the editor/creator program and Move256 is the bank builder and librarian.
The Wave256 and Move256 programs can be downloaded for free at

http://www.wiard.com

on the support page. (Wintel only sorry).
These programs create 64Kx8 binary image files that can be loaded
into EPROMs and used on the Mini-Wave. This allows you to create
your own wavetables and use them on the hardware.

You can use your own samples in the wave tables by this method (ugly but it
works). The waveforms are all 256 bytes long. At a 44.1Khz sampling rate
this means a complete waveform occurs at a 172 Hz rate. Using a program like
Sound Forge or Goldwave, sample your source at 44.1Khz eight bit (or 16 bit
then resample) tune the source to 172.26 HZ and sample at least 64K of time.
Save the sample as an 8 bit raw PCM file with a .256 extension. Now open
your target bank as "TO" in Move256 and your sample as "FROM". If you sample
is less than 64K you will get a file under-run error message. Now scan
through the waveforms in the sample until you get the zero-crossings aligned
with the beginning and end points of the waveform and move it to the "TO"
bank. Then save the "TO" bank.

A suitable EPROM programmer for the 27C512 EPROMs used in the Mini-Wave
can be gotten inexpensively from

http://www.needhams.com

The $139 model works fine (I use it).

A so called ROMulator can also be used, this substitutes
downloadable RAM for the EPROM and allows you to transfer
the binary files directly from your computer to the ROMulator,
which can immediately be played back on the Mini-Wave hardware.

I use the Tech-Tools Model EE512 detailed on this page

http://www.tech-tools.com/er2.htm

About $199 for the 512K version. This plugs into the EPROM socket
and connects to your computer serial port. Good for experimentation
and what-if play.

Footnote A:
Bank 15 is set up as a voltage quantizer, with 16 programmed scales.

Control Voltage Quantizer Mode
+/- 5 volts input give 0-5 volts output (5 Octaves)
Run control voltage to WS In and run WS Out to 1V/Octave input on
oscillator, Set output switch to 10 volt range

Wave Number:
0  Chromatic 12 notes per octave (4 steps per note)
1  Diatonic Major (C-D-E-F-G-A-B) Eight per octave (6 steps per note)
2  Diatonic Harmonic Minor (C-D-D#-F-G-G#-B) Eight per octave (6 steps per
note)
3  Diatonic Natural Minor (C-D-D#-F-G-G#-A#) Eight per octave (6 steps per
note)
4  Diatonic Dorian Mode (C-D-D#-F-G-A-A#) Eight per octave (6 steps per
note)
5  Diatonic Phygian Mode (C-C#-D#-F-G-G#-A#) Eight per octave (6 steps per
note)
6  Diatonic Lydian Mode (C-D-E-F#-G-A-B) Eight per octave (6 steps per note)
7  Diatonic Aolian Mode (C-D-E-F-G-G#-A#) Eight per octave (6 steps per
note)
8  Whole Tone (C-D-E-F#-G#-A#) 6 notes per octave (8 steps per note)
9  Pentatonic (C#-D#-F#-G#-A#) 5 notes per octave (10 steps per note)
10  C Major (C-E-G) 3 notes per octave (17 steps per note)
11  A minor (C-E-A)
12  G Major (D-G-B)
13  F major (C-F-A)
14  D major (D - F# - A)
15  Octaves one note per octave (46 steps per note)

Footnote B:
Mike Firman and I extracted the non-linear functions from the Serge
series of timbre modulators and I put up a page about them at

http://www.musicsynthesizer.com/nlt.htm

By taking the oscilloscope shots of the transfer functions and printing
them on transparencies, you can lay the transparencies on the computer
screen and hand trace the functions using the Wave256 program in the "Draw"
mode. This sounds very much like the Wave Multiplier and Wave Shaper modules
if you feed a variable amplitude sine wave into the waveshaper.

I am not going to supply this software in the EPROM since it would be rude
and possibly involve me in legal hassles. However the great interest shown
in the Mini-Wave by DIY prompts me to mention this, since the Serge NLT
functions would be a good starting place to continue research into
non-linear synthesis in general, and the Mini-Wave is an inexpensive
hardware platform to do so.