What's the difference between analog and digital when it comes to music production? This might sound like a dumb question, but isn't everything that's connected to electricity digital?
I'm going to answer in reverse order:
but isn't everything that's connected to electricity digital?
Not even close. Most likely, all the lights in your house are analog. Your kitchen appliances could go either way, but if they are at least ten years old then they are probably 100% analog. The fan in your bathroom ceiling is probably analog.
Let's talk music stuff. The following pages list musical products that are electronic and also analog:
- Everything made by Moog Music except the apps and the Theremini is analog
- Fender tube amps are analog
- Most Ampeg amps are all analog
- Everything made by Fulltone is analog
- Scroll down the "Analog Synthesizers" on Korg's product page for a list of their analog products
- Sweetwater's web site lists five pages of analog mixers from various companies (some have digital effects sections that can be bypassed)
- Looks like all of Manley Labs' pro audio equipment is analog
- Universal Audio has a page dedicated to their analog hardware
These are just a few examples. There are thousands upon thousands more analog musical products in the world.
What's the difference between analog and digital when it comes to music production?
Analog electronic musical equipment creates and processes sound using various electrical voltages that are manipulated using electronic components. In case it's not clear, all acoustic instruments are analog, but they are not electronic.
Digital musical equipment either samples an analog electrical waveform and turns it into a stream of numbers, or it generates a stream of numbers that represent an electrical waveform. Software is then used to change ("process") the stream of numbers in ways that serve a musical purpose. Since our ears and speaker drivers are analog, at some point the stream of numbers is converted to an analog electrical waveform and run through one or more speaker or headphone drivers and it becomes sound that enter our ears and we hear music.
Digital computers are everywhere - you are using one to view this web page. Digital musical equipment are digital computers that are purpose built to generate and process musical information. Digital computers convert analog voltages to numbers, process those numbers, and then convert the numbers back into voltages (it's a little more complicated than that but let's leave it there for this question).
Analog musical equipment are analog computers that process musical information. The voltages are processed directly, without being converted to numbers.
"Digital" means that at some stage in the recording process (if not all stages) an analog sound has been converted in a digital format, i.e. it has been sampled at a rate of 96 KHz (the normal rate these days; it used to be 44.1 KHz) and converted into "a long string of 0s and 1s". As most productions these days use computers, they are digital, as the computers use the digital format. "Analog" in this case means that the recording - of real instruments via microphones or direct injection - is to a physical tape recorder.
A comparison from the world of photography: all pictures taken by a smart phone or a digital camera are digital - that's why we are always told how many megapixels there are. A picture taken using film is analog - it is not sampled and converted. Theoretically this means that a filmed picture has infinite resolution; one can enlarge a filmed picture to any extent and always see a definite picture, whereas a digital picture will at some stage appear to be a sequence of dots.
With regard to music, it is much easier to manipulate digital recordings, but they have a definite resolution; the higher the sampling rate, the better the sound - or conversely, the lower the sampling rate, the worse the sound.
Also, the equipment used (primarily the "ADC", analogue to digital converter) plays a large part in the quality of the conversion. Compare the original version of an analogue record transferred to CD as opposed the a remixed version of the same record, or a record recorded with a 100% digital path.
Read about the Nyquist frequency, which explains the sampling rate.
Firstly, an explanation of the difference between analogue in digital in general terms. I ask you "How tall is your cat?"...
...that's an analogue way of conveying the information.
If you say "He's 28 cm high", that's a digital way of conveying the information. The actual physical amount has been represented as a number. (Note that the word digit means (a single) number - though we tend to use the term 'digital' to mean numbers represented in binary form).
The way analogue audio signals are converted to digital data streams is shown in this slide:
The audio data is sampled, then converted into (typically) a PCM bitstream that represents the waveform.
The main advantages and disadvantages of analogue and digital can still be seen by our cat-measuring analogy. If I want to actually record what the person showed me with their hands without using numbers (analogue), it's quite difficult to do - I might draw a line on a piece of paper that's the same size, but I'd probably make a small mistake. Then when I show someone else (with my hands) how big the cat is, I might make another mistake. And this is the problem with analogue - it's hard to keep copying the data accurately. With analogue audio, the 'height' (of the audio waveform) may be stored as magnetic patterns on a tape - but as you can imagine, if you keep copying the sound from one tape to another, you'll get distortion and noise.
If, on the other hand, I have the measurement digitally, things are much easier - I can write the number down, remember it, and copy that same number lots of times without it degrading. And that's one of the huge advantages of digital information - it can be stored and copied much more easily without introducing errors in doing so.
What's the disadvantage of digital, then? Well, we can probably guess that the cat wasn't exactly 28cm high - the 28 was a measurement made to a limited degree of resolution. We always have to make a choice, when we measure things, with how much resolution we want to do so - we can say 28, or 27.8, or 27.79... but we have to stop somewhere. Real-world digital systems do have a limited level of resolution - it's are limited by the bit depth of the system (and, in the time dimension, by the sample rate). However, well-designed digital systems these days are can store information to such a high degree of resolution that this fundamental limitation in how actually causes fewer problems than the noise and inaccuracies generated in analogue systems. They also have advantages of being able to store a lot more audio information in a smaller physical space, and these days, usually being a lot cheaper.
So, now that these very accurate digital systems are available, why would anyone still use an analogue system for recording and processing?
There are some reasons...
Avoiding latency. conversion between analogue and digital can be done quickly, but not instantaneously. If you need a super-immediate realtime system, analogue may be preferable,
'Warmth'. Some of the small distortions imparted by analogue systems can be subjectively pleasant...
Tolerance. ... while distortions added in digital systems are typically unpleasant. Specifically, we tend to try to avoid recording at too high a level on a digital system, as the way it clips the waveforms off square at the top sounds nasty. Some (not all) analogue systems are more gentle.
Physicality - It's fun to manipulate a tape or record with your hands. It doesn't work with digital - the electronics just get confused.
But for most use cases, these aren't enough to beat digital's practicality. Which is why the vast majority of audio recording and processing equipment being sold today is digital.
isn't everything that's connected to electricity digital?
No. You have to ask yourself if it is somehow storing or transmitting values, and representing them as specific numbers when it does so. If it's doing that, it's digital.
* yes, it also means 'finger'... those things on our hands we use to count with!