[sdiy] Taking a Step towards - - --((FUTURE-PREDICTIONS))-- - -

[Antti Huovilainen]

On Mon, 12 Jan 2004, Paul Maddox wrote:

> > Because despite 20 years of effort, analog still simply sounds better.
> Show me a resampling or wavetable engine done with analogue electronics, oh
> sorry, you can't do it..

Not fully, no. One could do such an engine that was clocked by analog vco
and drove analog filter & vca.
While purely digital techniques can create new sounds that are impossible
to with analog, I find analog sounds to be the best sounding. Analog
synthesis still has lots of room to explore. I find tube synths to create
very interesting and unique (and good sounding) sounds.

> ok, its do with oscillator drift some people say.. so why then do people
> spend hours and hours trying to make a perfectly stable oscillator?
> Some say its to do with the filters, but every analogue synth in the
> 70's/80's had different, and yet they all had this 'warmth'?

I'd say there are different flavors of "warmth". One is caused by VCF &
VCA. Having recently acquired a Waldorf Pulse, I have to say that it does
sound more warm (a certain flavor of "better) than my own softsynth, even
though I model the same VCF circuit.

I might get around building a computer controlled analog synth to measure
the warmth thing - find out what exactly makes analog synths sound warm.
On that subject, how linear are those multiplying DACs. Can I safely use
audio signal as the reference voltage without distorting the signal?

> I'm not going down this road, but lets just say its subjective..

As are all discussions where adjectives like "better" are mentioned.

> Hold on a moment, you said "analog still simply sounds better"
> now your saying the chameleon isnt powerful enough to do new things, and yet
> analogue synthesis is still same as it was 35 years ago (VCO->VCF->VCA)...
> so, I can say the same thing "analogue synthesis would be interesting if was
> more powerfull, if had the power to do new things"

I'd agree if you said "analogue synthesis would be MORE interesting...".
My opinion is that analogue synthesis can do certain types of sounds damn
well, while (pure) digital can do many sounds but none of them sound as
good.

> Anyone seen any analogue samplers?

Again, there's no reason why analog VCO couldn't clock the digital
oscillator. Early samplers did use analog VCFs & VCAs.

> I'm working on a VOSIM system, lets see you do that with a Prophet5.

Let's see you do Prophet5 pads in VOSIM ;)

> agreed, but manufacturers are realising that things need to 'imperfect' take
> the virus with its 'saturation parameter'.

The same problem may be with a too-perfect analog synth too. Another thing
worth a test (the computer controlled synth...).
Filter saturation is just the first step. Analog synths have plenty of
places where compromises that affect sound have been made (and they aren't
always obvious).

> > A synth I'd like to try (if I had time & money to build it) is a vector
> > synth that had high freq analog oscillators clocking digital wavetable
> > oscillators.
> Hold on, thats not analogue, surely it won't have warmth?

The important bits are analogue. Analog VCO -> drift, VCF & VCA -> rest of
analog sound. I built a simple VCO core once and patched it into
oscilloscope. VCO reset time was around 300ns, so I believe analog VCO
sawtooth waveform can be considered ideal.

> You can't get a VCO to run fast enough (say 128 times for PPG resoloution)
> over the full 10 octave range.

Decreasing capacitor size and using fast op-amp & comparator should allow
this. DAC speed does becomes an issue though.
One can get around this by "mipmapping" the waveforms. Once frequency
exceeds 600Hz, the upper 64 partials are out of audio range and one might
as well use a shorter waveform (64 samples long). Same thing happens again
at 1200Hz and so on.

> So perhaps when analogue electronics has advanced enough to do what I need,
> I'll rethink me stance.

I think there's an unnecessary division between pure analogue and pure
digital. Pure analogue on it's own sounds good but is limited in the kinds
of sounds it can produce. Pure digital is very flexible, but doesn't
sound as good (or good at all unless done right which it often isn't).
There is no reason best of both worlds couldn't be combined. One example
is the analog clocked wavetable oscillators being fed into analog vcf &
vca idea.

Antti

Give a man a fire, and he'll be warm that day,
Set him alight and he'll be warm for the rest of his life