EXS 24 Logic Sampler Users Group

Thoughts from the mind of Josh Emmons, 20-11-2002:

>For me, the difference is that CPUs, RAM, updates, USB, 802.11, 
>PCMCIA, and other computer industry techno-phrases are all explained
>very well in manuals or are at least documented in some book or another
>by O'Reilly & Associates.

You got a point there.  It's true, I think, that most VSTi's 
presuppose some synth background and don't do a very good job of 
explaining what VCO and VCF's are.  Never gave that much though, 
really.  I mean, if there was indeed such an explanatory section in 
any manual, I would skip it anyway... but come to think of it, I 
think you may be right.

>Not that I have anything against trial and error!  I think it's
>probably the best way to learn.  I'm just saying I can see how we got
>to this state of affairs when we can all talk on the same level about
>tech, but not about instruments or samplers, or whatever the heck a VCO
>is -- the tech knowledge is more accessible.

Yes, in a sense...  Still almost every synth, hardware or software, 
operates on the same basic principles: a sound generator (oscillator 
or samples) goes into a filter, which goes into an amplifier.  And 
these can all be modulated be either a periodic source (LFO) or a 
non-periodic source (ADSR).  And that's basically all there is to it, 
no matter how complicated it may get.  And this principle has been 
around since the first Moogs from the 60-ies.  So... in a sense this 
technology is ancient, and has been around in every synth for some 40 
years.  I guess I expected such an ancient technology to be somewhat 
"common sense" by now, despite the lack of documentation.  I thought 
that the mere fact that almost every synth has been operating on 
these principles for decades was enough to... spread the knowledge or 
something.

And yes, I know that in the above I ignore FM synthesis, additive 
synthesis, granular, virtual modelling, etc.  These are all still 
_relatively_ "niche" technologies though -- except maybe for FM.  The 
bulk of synths out there still use old fashioned subtractive 
synthesis.

BTW, there surely is a website somewhere that goes into the details 
of the various synthesis principles, isn't there?

And, for the record, a VCO is a Voltage Controlled Oscillator.  Old 
technology, commercialised for the masses by Moog, in which the 
frequency of an oscillator was determined by the incoming voltage. 
The keyboard would simply produce different voltages for different 
keys, and voila, you would have different notes when striking 
different keys.  All old analog synths use this same principle of 
voltage driven modules.  Very clever and flexible -- except that it 
was next to impossible to make polyphonic synths this way. So a VCF 
is a Voltage Controlled Filter, and a VCA is ditto, amplifier.
Some digital synths adapted this terminology, and called their 
oscillator a DCO -- a Digitally Controlled Oscillator -- suggesting 
some sort of connection with the old VCO, while there really isn't 
that much in common between the two (except that they both act as the 
sound source, of course).  Same with DCF's and DCA's.  A bit silly 
imo, but I suppose it got the message across so users would 
understand what the various parts did.  Okay, end of "ancient tech 
lecture".


-- 
Hendrik Jan Veenstra  <h@...>
Omega Art: http://www.ision.nl/users/h/index.html