[sdiy] There is no fun analogue chips anymore!

[Scott Gravenhorst]

Tom Wiltshire <tom at electricdruid.net> wrote:
>
>On 28 Jun 2012, at 02:18, KD KD wrote:
>
>> And now a "evil whiners" reflection!
>
>If I might play devil's advocate for a moment;
>
>Why exactly *would* there be any new interesting analog audio chips about?
>
>Given the cost of current digital audio solutions, there's really 
>no need. You can get 24-bit 192KHz codecs for less than a beer, 
>and powerful DSPs to go with them for only a couple of beers. The 
>result will do anything your analog chip could manage, and then 
>some. Who except a fool would buy an expensive specialised chip 
>to do something that you could do better with a cheap 
>general-purpose one? 
>
>Once upon a time, I was a hardcore analogophile and looked down 
>my nose at digital. But that was back in the days when you could 
>still tell the difference. Nowadays, the sampling rates are so 
>high, and the word sizes so large that digital is analog. The LSB 
>is way below the noise floor. On top of that, algorithms have 
>developed enormously and the understanding of the role played by 
>non-linear elements in many analog circuits has improved no end. 
>Judicious use of non-linear elements in digital designs has 
>enabled them to get the same sound as the analog stuff, since now 
>we're copying the limitations too. We're not far away from being 
>able to run Spice sims in realtime and get audio out. How would 
>that be for prototyping?! 
>
>The really interesting stuff will happen/happens when we go 
>beyond copying old analog gear (virtual analog is tiresome - why 
>do I want a digital oscillator that only has the same three 
>boring waveforms as some junk synth from the seventies?!) and 
>start doing stuff you can only do with digital, but adding in the 
>weird non-linearities and complexity that we've learned from 
>studying the analog stuff. Then we create digital synthesis with 
>character. 
>
>So forget about not having analog chips and go and do some 
>*really* crazy stuff with DSP instead. 
>

I have to +1 everything Tom just wrote.  It is the reason I've charged ahead with FPGAs
doing digital synthesis.  The digital domain does approach analog as word size and
sample rate increases in the same sense of a calculus limit.  I remember reading early
digital synthesis papers where the sample rates of 20 kilohertz were quoted because the
engines available then operated in the low megahertz.  In my opinion, we're at a point
where while there is a difference, it can be imperceptible unless you want to
intentionally do lowfi.  Polyphony is another reason.  Making a high quality polysynth
out of consumer analog parts is expensive, large and heavy and can't even come close to
the voice count nor the voice complexity of digital.  Not to mention tuning, amplitude
consistency, and even timbre consistency.  And I whole heartedly agree about digital
modeling of analog systems.  It's a good exercise, but we've been there and done that
and I think everyone here will agree that what we really want is new sounds and new
approaches to sound generation.  

Yes, there is a learning curve bullet to be bitten, but the process is no different
than the effort we put in to learn how analog systems work.  Once learned, it's part of
the design palette.

I too would ask why any manufacturer would want to pay engineers to design new and
better OTAs when the market for them can't possibly ever pay back the engineering cost
let alone eek out a profit doing it.  Now if someone has an enormous fortune of cash
and wants to be philanthropic toward the analog effort and make low cost analog ICs for
a market perhaps only in the hundreds of users, I'd say "knock yourself out".  Any takers?

-- ScottG
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-- Scott Gravenhorst
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