Home -> Magazines -> Issues -> Articles in this issue -> View
Vox Populi | |
Microvox Mimic Digital Sound EditorArticle from Electronic Soundmaker & Computer Music, September 1985 | |
High-spec sampler for the CBM 64

The sampling unit itself is a neat, (8" x 5½" x 3" — W x D x H) blue and cream-finished plastic box. Housing two programmable 24dB/octave filters along with the ADC/DAC hardware, the unit gives a very respectable S/N ratio of 59 dB, rising to an even more respectable 88 dB with the software-selectable companding switched in.
Front panel controls (which apply mainly to the Digital Delay mode — of which, more later) consist of Gain, Repeat (number of), Mix, (the balance between clean and delayed signal), Output level, and a mic/line jack in socket. Round the back, you've got the 26-way IDC ribbon connector (to the 64's cartridge slot), MIDI In/Out Dins, and a single Jack socket for Audio out (line level).
Loading time of the Editor program is about 1½ minutes — par for the course on the sluggardly 1541 drive. The first page, System Index, offers nine possibilities, selected either from the computer Function and Return keys, or, very sensibly, from joystick — a rationale used throughout the System. As Andrew Trott points out: "You're much more likely to be able to have a joystick next to you when you're working than a whole computer set-up". Step through the menu via the function keys or joystick - the currently selected option is highlighted. Selecting option 1 (Press 'Fire'/'Return') takes you, logically enough, through to the Sound Sampler Page.
Using it couldn't be simpler. Select Sample, and adjust the green Threshold bar so that it matches the incoming red Peak Level signal. Press Record, and as soon as the Threshold point is passed, recording begins. (Threshold defaults to "about halfway".) You can then immediately Listen to your sample across its pitch range, by playing it either from the top two rows of the QWERTY keyboard, or from an attached MIDI keyboard. The system defaults to Sample Mode 1, the highest bandwidth setting of 20 Khz (sample rate: 42Khz), which gives a maximum sample time of just under a second, and near-perfect reproduction. Remember — the original Fairlight spec offered only 14khz! This setting eats into memory though, and is unique in denying you access to some of the more esoteric editing options; so any of 7 other defaults, can be chosen instead, giving a maximum, in Sample Mode 8, of 19.5 seconds — at a fairly useless 1 Khz bandwidth! Still, it's nice to have the choice, and Sample Modes 2 to 4 all provide useful time/quality trade-offs, with a still-musical 2.5 seconds of 8Khz sampling available in Mode 4.
Sample Mode also determines how far a sample can be shifted up from its original pitch. (All Modes can be shifted down 2 octaves.) Mode 1 goes a measly 4 semitones, 2 is better at 1 octave, Modes 3 and 4 manage an additional 5 and 9 semitones respectively, while Modes 5 to 8 all go up a full two octaves. I imagine most people will opt for Mode 2, most of the time, with its sensible 1.5s sample time/13 Khz bandwidth (27 Khz sample rate) tradeoff.
Noise reduction, in the form of Companding, can be applied if desired, with impressive results, though it does rather take the edge off brighter sounds such as cymbals and guitars. Also helping out on the sound side of the things are the two programmable 24dB filters, one for input, one for output, which can be used to cut hiss at the record stage, or remove quantization error noise on playback. Having two, independently programmable filters gives you a lot of musical latitude - full marks for putting that ahead of fixed, 'correct' filter values.
Assuming that the sample you've recorded sounds alright on a first Listen, then you'll probably want to edit it; so Exit to System Index, and onto option 2, the Waveform Editor, a two-page section. First up is the Dynamic page, which automatically draws the entire waveform, Fairlight page 8-style. Time taken to complete this depends on the complexity and duration of the sample, but it's never more than a few seconds. Now the fun begins. The overall envelope of the sound is fixed by three 'Flags', selected from the onscreen menu as appropriate — green for Start Point, red for End, and Blue for Loop. The sample will play from the Start, to the End, and then Loop continuously from the Loop Point to the end. Usually, therefore, Loop and Start will be at the same place — but they don't have to be...
Moving these three through the sample and placing them is again via joystick or function keys. Usually the start and end points are obvious, and placing the relevant flags on these simply tidies up the sample for playback. Finding a suitable loop point, though, can be a bit tricky, so to help out, there is a second, hi-res page which allows you to step through each of the 128 bytes which constitute each segment of the overall sample one by one, until you find two adjoining segments which are similar — the mark of a good loop-point. Once found, the Loop flag is placed as before. If on Listening, the sample still glitches, don't worry — just try again. All of the original sample remains intact. Although this procedure seems quite arduous, in practice, it's simple and reasonably quick. However, with complex or layered sounds, things can get tough — so the possibility of an 'Auto-Loop' update a la Greengate is being looked into.

In the pipeline, along with the Sound Library Disks, are a Fourier Synthesis package — enabling you to build up sounds harmonic by harmonic, in a way not unlike the Wave or DX7, plus perhaps further updates to the Sequencer package. Andrew Trott also mentioned that the bandwidth and sample times of the Microvox might also change — but only for the better!
Mr. Trott himself is looking forward to the establishment of the Commodore 128 in this country, which he reckons will be powerful and fast enough to handle a polyphonic version of the Microvox.
Everything about the Microvox impressed me — its (carefully worked-out) user friendliness, the commitment and enthusiasm of the people involved in it, the 'extra' DDL, it's great value-for-money price — but above all, the quality and clarity of its sampled voices. There's never been a better reason for buying a Commodore.
Price: £229
Contact: Supersoft (Contact Details)
Supersoft Micro Vox Sampler
(12T Dec 85)
Vox Pop - Microvox Sampling System
(EMM Apr 86)
Browse category: Software: Sampler > Supersoft
Review by Tony Reed
mu:zines is the result of thousands of hours of effort, and will require many thousands more going forward to reach our goals of getting all this content online.
If you value this resource, you can support this project - it really helps!
New issues that have been donated or scanned for us this month.
All donations and support are gratefully appreciated - thank you.
Do you have any of these magazine issues?
If so, and you can donate, lend or scan them to help complete our archive, please get in touch via the Contribute page - thanks!