What makes analog so analog?

[Robert Randolph]

what makes analog sound so... well, analog?

snobs

damn those digital snobs. let's get rid of them all.

[WhiteNoise]

This is a question I think most programmers are trying to work out.. If you can figure this out, you'll be rich. But seriously, I think there are a lot of things that go into the analog sound. Filters are just as important if not more important than the oscs. It's pretty easy to do near-perfect oscillators (ie, no aliasing) using tables and things. Tuning instabilities and noise can be modelled for the most part. Nonlinearities and distortions are where things get interesting and start to really affect the tone - filters are where most of these occur AFAIK. I can still hear the difference between digital filters and my analog gear. As Dr. Wackler said, there is no instant feedback either - this turns out to be a big problem with trying to emulate the famous moog filters which are not possible to emulate exactly because of this. I suspect however as some people have said, that once we get enough processing power and a high enough sample rate, that the differences may become totally undetectable. Digital systems are all approximations of analog ones. The approximation gets better and better (closer to the curve) and human beings have finite limits on what their senses can detect. It's just a matter of pushing the approximations past those limits (in theory anyway).

[McLilith]

One may think that even the analog signal needs a (however small) fraction of time between the original signal and the fed back signal - but that's not what feedback is. Analog feedback actually does happen the very moment that the original signal that causes the feedback is happening.

That's really cute. You're quoting yourself as an "expert witness" of sorts.

Unfortunately, you neither you nor your own "expert testimony" are correct.

For example, guitar feedback involves acoustic energy that has to travel from a speaker to a guitar to complete the feedback path. Since that path has a length greater than zero, and sound travels at a less than infinite speed, there is indeed a delay time associated with guitar feedback.

With an audio amplifier or other electronic audio circuit there is always a short, but measureable delay between the signal coming in and the resultant amplified signal coming out. Also, amplifiers can only change the out voltage so fast. If you could somehow feed a perfect square wave into an audio amplifier, you would find that the output signal would not have perfectly vertical transistions like a perfect square wave should have. Rather, your output is a trapezoidal waveform. What should be perfectly vertical and instantaneos transitions are turned into slower ramp-like transitions, because of the amplifier's inherent slew rate.

I'm telling you there are minor delays associated with practically all electronic circuits, if you want to look closely enough. In order for feeback to be absolutely and truly instantaneous, it would involve transmitting data at speeds infinitely greater than the speed of light. Is this really what you want us to believe is happening?


take care,
McLilith

[meister eder]

I would describe it as feeling more like a sensation of "pressure" than "normal sound". One day, while suffering from a severe headache, I was able to detect a 200 kHz sine wave. Once again, I couldn't sense the pitch, only the presence of the signal, and it felt like a dull sensation of "pressure." I only know that it was 200 kHz, because it was being generated by a friend with a signal generator that maxed out at 200 kHz, and he was playing it at the highest frequency setting.

The main point that I would like to make is that there are lots of subtle nuances that humans (at least some of us) receive from frequencies outside the traditional "textbook" range of human hearing. This is an area that isn't isn't well understood yet, but there are definitely things above 20 kHz that affect people in various ways.

Well said!
And especially the part where you describe it as "pressure" is exactly what I am experiencing as well, but never knew how to describe it. "Pressure" just perfectly fits it! Interesting to hear that you as well seem to be more sensitive to such things when you have a headache.

[Lawnmower Of The Damned]

WhiteNoise, I won't pretend I know as much about this as you do. I'd lose that arguement in a heartbeat. Do you believe (And I am not saying this sarcasticly, I am genuinely asking your professional opinion, which I respect) that an analog filter would work better? Then how about the same system as before, only with a analog filter instead of an oscillator?

I'm curious why things like Creamware cards with 14 Sharc processors still can't seem to capture that analog sound. It doesn't seem like it's a limitation of the processing power (My Vetta only has 2 Sharc processors, and it still blows my mind every time I turn it on) but more a problem with the way that we are trying to re-create the sounds.

VSTi's are great, and I do love them. I can download Synth Edit for free right now, and slap together a synth with more features than a lot of $1,000+ analog synths had 15 years ago. I think that's wonderful, and I am the first to admit that analog will never be able to do the amazing stuff that VSTi's were doing years ago.

But I still crave that analog sound. It seems like the easiest solution is a digital/analog hybrid. To get back to my original question (Has it already been 3 pages!?):What part of a digital system do YOU think would be best to replace with an analog piece? That analog sound is in there somewhere, now it's just a matter of finding the little bugger, and making it available to the masses with VSTi's.

[tony tony chopper]

I wrote snobs because it's funny to find some of them thinking that their 'analog gear' sounds better, while it's sometimes just virtual analog (read: digital).
I don't know hardware synths much (if at all), but I know that the virus is not analog, and yet I've read people thinking it was, or claiming it couldn't be done digitally.
I've even read about some FM synths that they sounded 'too digital for a FM synth'

One of my guess though: free running oscillators. From what I know from old bassline synths, they had basic oscillator(s) that weren't retriggered, giving that 'always different' sound on each note. It's easy to make a digital synth and forget about free running (or some randomization on the starting phase of each note's oscillators). That little variation on each note makes it more 'human'.

Here's an example, first part without free running and second part with. But here I'm cheating since the difference comes from the unison affected a lot by the free running.
But you get the idea with low basses: if it's a single oscillator that's never retriggered, and the level envelope is applied to it, that envelope will start at different phases of the oscillator, giving a sound that's different for each note (especially in its attack).

http://www.flstudio.com/gol/FRunning.mp3

[McLilith]

Well said!
And especially the part where you describe it as "pressure" is exactly what I am experiencing as well, but never knew how to describe it. "Pressure" just perfectly fits it! Interesting to hear that you as well seem to be more sensitive to such things when you have a headache.

At least we agree on this topic.

You might possibly be the first person I've met online who seems to have a similar experience as what I've had. Do CRT monitors hurt your head? They hurt mine. I'm in constant pain when I use my computer, but then again, I keep a nearly constant headache anyway. The monitor only makes it a few percent worse, so I just try to live through it. These darn computers are so adictive, you know.


take care,
McLilith

[ocp]

I vote for the filter.
But hey, you can always buy an analog filter and route your VSTi's signal through it.
Here's a neat'n'cheap one (the Megapole lite): http://anyware-instruments.de/navi_new/ ... glish.html

[Joxer the Mighty]

But I still crave that analog sound. It seems like the easiest solution is a digital/analog hybrid. To get back to my original question (Has it already been 3 pages!?):What part of a digital system do YOU think would be best to replace with an analog piece? That analog sound is in there somewhere, now it's just a matter of finding the little bugger, and making it available to the masses with VSTi's.

I think the whole point of what's been posted is that the analog sound is the sum of many different factors, some of which we may never be able to duplicate digitally. I don't believe there is one digital component of a vsti that can be 'swapped out' for its analog counterpart, and suddenly give that vsti the analog sound.

[tony tony chopper]

And especially the part where you describe it as "pressure" is exactly what I am experiencing as well, but never knew how to describe it.

I describe mine as sinusitis

[meister eder]

One may think that even the analog signal needs a (however small) fraction of time between the original signal and the fed back signal - but that's not what feedback is. Analog feedback actually does happen the very moment that the original signal that causes the feedback is happening.

That's really cute. You're quoting yourself as an "expert witness" of sorts.

Unfortunately, you neither you nor your own "expert testimony" are correct.

For example, guitar feedback involves acoustic energy that has to travel from a speaker to a guitar to complete the feedback path. Since that path has a length greater than zero, and sound travels at a less than infinite speed, there is indeed a delay time associated with guitar feedback.

With an audio amplifier or other electronic audio circuit there is always a short, but measureable delay between the signal coming in and the resultant amplified signal coming out. Also, amplifiers can only change the out voltage so fast. If you could somehow feed a perfect square wave into an audio amplifier, you would find that the output signal would not have perfectly vertical transistions like a perfect square wave should have. Rather, your output is a trapezoidal waveform. What should be perfectly vertical and instantaneos transitions are turned into slower ramp-like transitions, because of the amplifier's inherent slew rate.

I'm telling you there are minor delays associated with practically all electronic circuits, if you want to look closely enough. In order for feeback to be absolutely and truly instantaneous, it would involve transmitting data at speeds infinitely greater than the speed of light. Is this really what you want us to believe is happening?

1. I was not quoting myself as a "expert testimony". It was just easier to quote my already given answer to your point (which was a reply to an earlier post) than to write all again. Just one request: Don't you ever again use the word 'cute' for anything that's got to do with me - I hate this, it's just plain condescending.

2. What you describe above may be all true, but that's not what feedback is. Feedback does happen the very moment that the original signal that causes the feedback is happening. None of your attempts to argue against that fact will change that fact. If you read my quoted post again, you'll realize that I've taken your point about speed of transmission into account, so no reason to explain it to me.

3. In case you want me to explain it further, here's just one little hint: The point where your argument fails is where you write about the feedback path. You presume that the feedback is already defined when the signal enters the feedback path. But that's wrong and you will agree with your understanding of causality. The feedback itself actually happens at the very end of the feedback path. And that's why it is instantanuous. Makes sense? Then let's not continue this nitpicking.

[Lawnmower Of The Damned]

Joxer, has anyone ever called you a pessamist?

It may be that it's not possible to re-create an analog synth digitally, but I'd still like to try. This is just my idea of what I think would really work the best. Whether it's spot on or not, I'd be stupid to tell you it would be perfect. But don't you think it might be a bit closer?

[McLilith]

I describe mine as sinusitis

Well, that might be the proper description of your personal medical condition, but it doesn't really describe the acoustic energy you are able to detect.

Now that you bring it up, sinusitis is definitely one of the medically documented physical conditions that are known to extend the upper range of human hearing well beyond 20 kHz.


later,
McLilith

[Lawnmower Of The Damned]

OCP, NICE! You posted on topic!! And the site provided sound samples!!!

I liked the sound of the filter, but I'd need to hear it in context to be certain if that seems like the best answer.

Anyone else have more stuff like this to post?

[meister eder]

And especially the part where you describe it as "pressure" is exactly what I am experiencing as well, but never knew how to describe it.

I describe mine as sinusitis