Difference Between Analog and Digital

Yes, just as there are analog synthesizers and digital synthesizers.

The former differ from the latter in the generation and processing of the generated sound.

In analog ones, a waveform is generated by means of an oscillator; this waveform is then filtered by a filter that allows cutting high frequencies, a low-pass filter, or low frequencies (high-pass filter).

These are the "simplest" filters; there are others, but usually in the typical analog synthesizer of the 60s/70s, there is only one filter,

and it is the low-pass one, which essentially determines its timbre.

In analog synths, you cannot recreate the typical sounds of digital synthesizers (which rely on numerical codes, therefore on preset sound tables and, as they say, "frozen" in a non-modifiable ROM memory, which differs from RAM memory, which is usually used to load new sounds that must nevertheless be saved on a specific bank (a sort of warehouse), or on floppy disks (if they are small in size), until a few years ago on Zip disks (removable hard disks of about 100 MB and more), on hard drives,

lately on micro SD cards up to 32/64 GB, etc..

In digital synthesizers, it is possible to have a greater variety of sounds, which are usually classified according to the MIDI standard protocol, i.e., 127 sounds starting with piano timbres, electric piano, etc., to cover, let's say, every acoustic instrument, up to purely synthetic sounds (even if those acoustic ones are always synthetic because they are, indeed, samplings—reproduction of the timbre of an acoustic instrument, for example, recorded in its full range, with specific qualities: kHz, bits, duration, loops, etc., with parameters that have always been a problem, such as sound attack, resonance in piano sound, or even a string instrument, and many others). These 127 sounds refer to the 127 standard MIDI parameters, which cover the parameters for modifying the "perception of sound," not synthesis in the strict sense (subtractive synthesis, typical of analog synths; additive synthesis, FM, and others), but as a modification of performance parameters, if we want to define them that way: attack, decay, release, etc. However, some of these are defined specifically; for example, the force with which a piano key is pressed is called "velocity," so not execution speed, but I could say intensity of the attack, which nonetheless is not the same thing).

To summarize, the difference between analog and digital signals lies in the fact that in analog, the signal is continuous, without interruptions; by changing the position of a potentiometer, whether it be for filter resonance or cutoff (cutting the threshold value, the frequency of the filter in this case), all values can be covered. In digital, however, these are "preset," and the range moves between these specific points. This is why, especially when talking about analog versus digital filters, the difference is always noticeable—even better if there is analog generation at the base rather than digital generation with an analog filter (a hybrid).

Anyway, it seems simple but it isn't, and I realize that if I explain it, it might not be understood very well; someone needs to explain it better and more exhaustively. I have the feeling of having gone in circles around the subject.

When I read the first post, my first thought went toward the two different types of approach and the limits of digital compared to analog.

Tell the truth

Frank wrote:

When I read the first post, my first thought went toward the two different types of approach and the limits of digital compared to analog.

Tell the truth, I could have spared myself all that mess I wrote, right?

You're right, that is the core of the question, but to explain things I always get tangled up; in fact, I introduced other topics that

don't relate to this, otherwise there would be no way out; I see with pleasure that I could have been a teacher, they would have understood me instantly

Piccinesco wrote:

Tell the truth

Tell the truth, I could have saved myself all that mess I wrote, right?

You're right, the crux of the question is that, but to explain things I always get tangled up; in fact, I didn't introduce other topics that

are irrelevant to this, otherwise there would be no way out. I see with pleasure that I could have been a teacher, they would have understood me instantly

I found your intervention interesting; instead, I am curious about the "crux of the question" ... which I probably touched upon unconsciously

Lupino wrote:

i am curious about the "core of the question" ... which I probably touched upon unintentionally

Dated that it is not mine, I can spend it "serenely"; there are those who claim that works created by passing through analog rather than digital are of better craftsmanship ... and I partially agree.

Stimulated by the recent discussions, I found this interesting short thesis

http://www.suonoelettronico.com/introduzione.htm

I am sharing it because it touches on many important aspects and perhaps helps to bring clarity to the topic

Small contribution.

Analog means that sound generation is done using devices that electrically generate something analogous to a sound pressure wave (which is what our ear is sensitive to).

Digital (from the English digit=numerical figure) means that generation occurs with devices that interpret long series of numbers.

Both technologies each have pros and cons (as everything in this world does).

The digital one has taken hold and today is dominant because it is more convenient.

The turntable with the tonearm and cartridge produced electrical waves starting from the vibration of the stylus in the groove; the amplifier and the speaker carry everything as acoustic pressure toward our precious ears.

The vibration is analogous to the pressure.

The CD, instead, starts from a list of numbers to produce the same thing.

Here is the difference between analog and digital.

I hope I have been clear and concise...

Thanks to you too, Chickbone

Alternatively, think of a clock with hands: that is analog, it marks EVERY instant; the one with digits (digital, precisely) marks 11:01, 11:02, and so on. It does not mark intermediate moments.

It is what is defined (if I recall correctly) as the difference between a "continuous" function and a "discrete" one: one includes all values, the other proceeds in "steps," without intermediate values.

It is a somewhat coarse definition, but given the time...

Doc, you've taken a difficult example that can illustrate the point, and I am referring to the fact that you stop at the hands, but that is not the delta. There are digital clocks with hands... and so you can see time "flowing" in every single moment.

What changes between digital and analog is the system behind the production of the "visual" result; that is, given the same hands, on one hand you have mechanics and on the other you have electronics... even if the representation system has also changed over time by moving to numbers, it doesn't shift the substantial difference between the "devices"... which is what makes sense when comparing an analog logic to a digital one.

What do you think? Taking this into account, how would you weave your argument?

mmm... actually, the point I was making was more related to the concept of analog/digital, not to the devices (analog and digital synthesizers exist, but they are both electronic);

it is just to represent (roughly) the concept: for example, a keyed electric bass can be defined as "digital", and a non-keyed one as "analog".

a bit of what Piccinesco says at the end of his first post, just said in a coarser way...

Perhaps a more apt example could be the difference between a vinyl record and a CD: in the former, a crescendo is reproduced mechanically, passing through the entire dynamic range; in the latter, to be reproduced electronically, the data are converted into numbers (digits), so you will have a series of values (1, 2, 3, 4 ... etc.) more or less complete depending on (0.1, 0.2, 0.3 ... etc.) the definition you want to achieve and the space you want to occupy with the data. In practice, here the crescendo proceeds in "steps," but our ear still perceives it as continuous due to a limit of our perception (but that is another matter).

Here I return again to Piccinesco's point: a digital synthesizer can indeed reproduce the sound of any instrument, even acoustic ones, because through sampling it "photographs" the sound and converts it into numbers, but it encounters problems in reproducing complex sounds like that of a piano, because to reproduce exactly all the notes, each with all possible types of attack, decay, and dynamics, it would have to store an enormous amount of data and use gigabytes of memory.

Sorry but ... piano versus clavinova?

Sliding a bit off topic, we could indulge in a discussion about the fact that in nature, or at least according to our perception, "continuity" practically does not exist...

jack wrote:

Excuse me, but ... piano versus clavinova?

well, here the difference is evident. it is clear that the clavinova is not able to reproduce exactly all the nuances of the acoustic sound; in return, it enjoys the advantages offered by electronics (sound manipulation, various interfaces, various adjustments... reduced footprint...).

DrJellyfish wrote:

a digital synthesizer can indeed reproduce the sound of any instrument, even acoustic ones, because through sampling it "photographs" the sound and converts it into numbers, but it encounters problems in reproducing complex sounds like that of a piano, because to exactly reproduce all the notes, each with all possible types of attack, decay, and dynamics, it would have to store an enormous amount of data and use gigabytes of memory.

...but all of it, or how much is truly perceptible by the ear?"}

Gassy wrote:

...but all or how much is truly perceptible by the ear?

believe me, a good question... well, I would say that the difference between an acoustic piano and an electric one can be heard; perhaps the samplings of other instruments can be misleading.

The true analog-sampled sound can only be heard with a vinyl record, period! Sampling in analog means recording directly onto vinyl; many movements are made by the microphone diaphragm in a continuous field, many grooves are made by the recording needle on the vinyl (in a continuous field). Recording digitally and then transferring the content to vinyl is still an analogized digital product... and therefore always digital.

The difference exists and, within certain limits, it can be heard. If we are talking about samples and acoustic pianos, then there's no comparison—what does that have to do with it? It's like talking about your own voice and then hearing yourself recorded. We perceive sound not only through our ears but through our entire body. Microphones simulate human ears, certainly not the body. This is one reason why our recorded voice seems so different from our real one. With instruments, the argument makes no difference. Recording a piano and hearing its recorded sound again is a completely different thing. That is why piano sounds in post-production are often colored with a bit of reverb, precisely because one tries to make that recorded sound resemble what we perceive at the moment we are playing, which also takes into account the environment (the total state) surrounding us.

Listening to a CD or a vinyl record is now normal practice, but no one imagines the enormous work behind its creation, whether analog or digital...