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Conference napalm::commusic_v1

Title:* * Computer Music, MIDI, and Related Topics * *
Notice:Conference has been write-locked. Use new version.
Moderator:DYPSS1::SCHAFER
Created:Thu Feb 20 1986
Last Modified:Mon Aug 29 1994
Last Successful Update:Fri Jun 06 1997
Number of topics:2852
Total number of notes:33157

20.0. "The REAL ideal Synth" by VIKING::MARKEY () Sat Jun 09 1984 20:00

I have read with interest some of the things which supposedly make up
the ideal digital synthesizer, as proposed herin.  Let me state that
what was presented within in NO way represents an ideal, and in fact
largely indicates a lack of understanding as to the possible ideals
of a synthesizer.   First let me introduce myself.  Aside of my
temporary tenure as a contract member of the Rainbow software development
group, I am president and founder of CompSync incorporated, a Mass
based manufacturer of digital music equipment.

My company's model 2000 synthesizer is to be announced and demonstrated
at the upcoming October convention of the Audio Engineering Society.
Some of you are obviously aware of the Fairlight and Synclavier machines.
You may have noted, with some interest, that they do NOT require a VAX,
in a manner or manifest. In fact, the requirement is for special high
speed processing BEYOND the (in this case) limits of the VAX.  My
company is a joint partnership with Syco Systems, England (and Europes)
largest distributor of such equipment.  They were originally founded to
market the Fairlight in Europe, for that matter.  I have used both
machines extensively, and can state in no uncertain terms that they far
exceed any and all of the ideals presented here.  My own machine goes
much further still.

First we use the ever popular FM technology.  A special FM ENGINE computes,
in real time, the combination of the phase angle of a fundamental wave,
in combination with the SIN of the phase angle of a modulating wave
multiplied by a modulation index in the range of 12 bits.  What this
amounts to is control over 2000 possible silultaneous harmonics.  The
machine produces 48232 16 bit samples per second, per the PCM standard.
The combined phase angles may be presented to a group of linear wave
tables, which may be paged from a Winchester disk in 'psuedo-real-time',
or as fast as human perception is capable of deriving.  The contents
of the tables may be generated by the light pen drawing of an arbitrary
number fo harmonics, or better still by sampling.  Our sampling technique
involves analyzing the waveform to first pick out a discernable cycle
of the input waveform.  The frequency content and envelope for the
period are then interpolated and fed to the FM Engine as operating
parameters.  When the sampled waveform ventures too far from the current
waveshape, a new group of parmameters is loaded.  At all times the
basic waveshape is stored in 16 x 256 byte wavetables for each voice.
As the tables are scanned, unused ones are swapped out.  There may
be a total of 16 instruments defined at one time, 4 on each of
two keyboards (slave optional), and 8 from the built in recorder.
The system may have up to 64 voices (in increments of 16).

Oddly enough, another product is to be introduced by our company
in the fall involving control of multiple keyboards, sequencers,
and drum machines.   We hope to steer the market a bit away from the
almost useless MIDI.  We will (groan) support MIDI none-the-less
in all our products.

Please address all inquiries pertaining to the CompSync product
line to -

Marketing Manager
CompSync Incorporated
168 Winthrop Street
Framingham, MA 01701

Hope to see some of you at AES in the fall.  We'll also be at the
NAMM show in November.  We are skipping the spring show in Chicago,
although I will be attending anyway.
T.RTitleUserPersonal
Name
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20.1XENON::SAUTERMon Jun 11 1984 09:2123
I want a VAX (or similar data processing system) as part of my music
synthesizer not to do FM synthesis but to do data processing work on the
music.  For example, storing and retrieving songs in named files,
backing up said files and exchanging them with other people.  Obviously,
a new song can take parts, such as instrument definitions and even
phrases, from old songs.  I would also like to do analysis of songs,
such as determining their running time and the range of each part. 
Since my VAX can communicate with others, if I don't have a printer
myself I can print my music as a score on someone else's printer.  A VAX
with a MIDI interface can do all of these things for any synthesizer
that supports MIDI, given proper software. 
 
I don't want to ask about your product, since you gave us an address for
that, and it is unannounced, but could you say a few more words about
your dislike of MIDI.  My biggest problem with it is its speed--you can
only specify new notes at the rate of 1000 per second, which is likely
not fast enough for complex passages involving lots of instruments. Your
machine is clearly 'high-end', like the Fairlight.  Assuming you and the
other 'high-end' manufacturers got together with the 'high-end'
customers, such as Industrial Light and Magic, to produce a better
interface, how would it differ from MIDI?  Would it be a better
interface for 'low-end' products, such as the Yamaha DX7? 
    John Sauter
20.2VIKING::MARKEYThu Jun 14 1984 18:1218
My complaint with MIDI is general - architecture.  Given the organization
of the system they have done a good job, but I would much prefer a better
organization.  I feel that a true parallel data arrangement that could
handle the throughput of any sample driven system would be superior.
Such tecnhology is available now.  I prefer to use the IEEE-488 standard
interface, mostly because of the already existing add-ons to such
systems like Spectrum analyzers, etc.  CompSync intends to introuduce
an IEEE-488 linkable control voltage generator/sequencer, and also a
'dynamic patcher', which is a group of analog tri-states that have
programmable combinations of in-outs for use in modular systems, such
as Roland's.  In general you will find that companies, such as
CompSync that participate in the high-end market are not all that fond
of MIDI.  It is a very LOW end solution to a very complex problem.

You might note that none of the MIDI desingers were ever network
architects, and what after all is such a system ???

Brian Markey
20.3Doesn't sound ideal. Maybe for home heating...MAY20::BAILEYSteph BaileyWed Oct 07 1987 19:2120
    I was just re-reading the early notes in the file when I stumbled
    across ``this''.  Read the base note (20.0) and tell me what you
    think.
    
    For all the frequency modulation and phase angles and wave tables
    and harmonics and light pens and sampling and envelopes and hard
    disk and slave keyboards, I haven't the foggiest where the sound
    comes out.  Is he implying that there is some form of FM which is
    used as an index into a wave table which after a multitude of
    mutilations comes out through a DAC?
    
    Sounds like the sort of useless complexity you get when you stack
    6 or 8 operators in a single FM stack.
    
    Anybody heard anything from this company since?  (Gee boss, I ain't
    never heard of a CompSync...   Sting uses one all over his latest
    album.)
    
    Steph
    
20.4BARNUM::RHODESThu Oct 08 1987 09:3513
The basis of what I get out of .0 is that FM is used to derive waveforms,
which are then converted into wavetables (basically sampling the FM waveform
within the digital domain).  A large number of these wavetables can be stored
on hard disk, and swapped in on demand in pseudo real time (probably a function
of key velocity, modulation, or just plain multitimbrality via different
MIDI [or IEEE-488] channels) giving the illusion of n voice multitimbrality,
where n is very large.  Kind of like on-demand virtual voice paging.  I 
don't understand how a hard disk is gonna do a seek and read and data 
transfer (16x256=4k bits) fast enough to not be noticeable though, which 
may explain why we havn't seen the beast.

Todd.

20.5this?BARNUM::RHODESThu Oct 08 1987 09:4310
Well, upon rereading, I see that I'm off the mark.  The wavetable waveforms
are sampled or entered via light pen, and fed into the FM engine to modulate
each other.  The demand wavetable still stands.

Sounds like the volume envelope is stolen from one of the wavetables and
fed to the FM unit so that the FM waveform envelope emulates the one in
the wavetable.

Todd.

20.6huh?HAMER::COCCOLIWed Nov 16 1988 23:051
    pseudo real time?