Aloha to Paul!
Great to see Moe and Crow describe the distinction. I've never liked the term
"synthesizer (after all, what is it which is "synthesized" from a
synthesizer?) and have really avoided thinking in these terms -- I prefer to
use terms like "voltage controlled or digital electronic music."
Anyway....
In a message dated 5/19/2000 7:39:56 AM,
daveb@... writes:
>Some truisms:
>1. Microprocessor control of analog circuitry does not make it digital.
>2. A digitally controlled oscillator (DCO) is still analog if the basic
>"charge pump" sawtooth generator is still there.
>3. An oscillator that derives its basic frequency from a counter and has
>waveforms derived from it, will never be analog.
I'd like to hear more about these distinctions (2 & 3) since they both seem
to indicate a counter driven oscillator (at least I thought that's what 2
does) with a continuous output.
>4. An analog oscillator can be constructed of transistors, ICs, or totally
>integrated onto a single chip. SSM, Curtis VCOs are 100% analog even though
>they are on a chip. The new Alesis Andromeda has a custom chip with 100%
>analog VCOs, filters, and VCAs.
What about those CEM ICs that are synth-voice-on-a-chip (like the CEM3394 or
3396 -- I forget which) which take a pulse input (presumably from a uP) and
output a VC continuous waveform?
>5. Some modules in an otherwise analog modular synth are digital. A
>sequencer is by nature partly digital. The MOTM-120 uses digital counters
>to
>do digital ring modulation.
>6. Analog polysynths are still allowed to be called analog even if they
>are
>digitally controlled for preset purposes, even if a computer and analog
>to
>digital converter sits between every panel knob and the actual circuits,
>even if certain control signals such as LFOs and EGs are directly digitally
>generated.
>So if you are talking preset polysynths, the convention is to call them
>analog if at least the VCOs, VCFs, and VCAs are analog, even if digitally
>controlled. Then you get into a gray area where you have DCOs, digital
>VCOs
>with analog filters
I'd think that the Junos would be VC without regard to the oscillators since
they have VCF, VCA and an ADSR.
>With a modular, you have to talk about it on a module by module basis.
>Generally, all the basic synth functions are 100% analog, and you have
>some
>special purpose modules that have some digital in them. But only when it
>makes sense in its own right, not as a compromise solution!
And further...
In a message dated 5/21/2000 1:51:55 PM,
jhaible@... writes:
>You can count the current position (step number) with your fingers.
>
>JH.
Not on my 16 stage sequencer I can't, I have to take off my shoes for that!
(sorry guys)
> I'm not sure I understand this part. As far as I know, there is nothing
>digital about my Serge or Roland System 100 sequencers (but I could be
>wrong). Care to elaborate?
As JH so concisely points out, stage position is determined digitally, in
fact there are four 4051 CMOS (digital) ICs in the Serge (I'm sure there's a
bunch more digital stuff in there as well). The clock (pulse) signals can
also be thought of as digital (either a 1 or 0), and as such there can be a
significant number of uses for appropriate "digital" modules in a VC system.
The Emu had a whole bunch of "logic" modules which looked from the users
point of view like a bunch of CMOS chips. These modules (like a flip flop, a
triple latch, a logical inverter, etc.) were very useful in making basic
sequencer patches much more interesting (i.e., less periodic). Maybe Moe can
add something about the Emu modules if he found them useful.
JB