A frequent debate is whether analogue audio still sounds better than digital audio. Actually this is the basis for the never-ending discussion of analogue versus digital audio. These days vinyl records are becoming more and more popular, simply because people like the warm tone and other characteristics of an LP. Even many audiophiles prefer the analogue sound of LPs and some of them even use tape machines to play their music.
When digital audio was introduced to the consumer market in the eighties, it didn’t sound very good. Restoration filters and aliasing filters of decent quality, which are now widely used, weren’t available at that time. For this reason many people didn’t like digital sound. A lot of big studios even kept using tape machines to record their music instead of a state of the art computer system. It took until the year 2000 for digital systems to be capable of replacing the analogue tape machines. However, many people find that digital audio sounds quite clinical. So why does analogue sound ‘better’?
From a technical point of view, analogue audio (note: analogue audio, not analogue recordings) is clearly superior since digital audio will always be a reproduction of the analogue source although the difference is almost inaudible. Digital audio is always limited through sample rates and bit rates while these limitations simply don’t exist in the analogue domain. For example: Pentatone’s remastered classics series were taken from analogue recording that were made 40 years ago. The original tape was carefully converted into DSD files, the best format for archiving at the moment. The original analogue tapes were good enough to serve as the basis for the DSD files. However, analogue audio does have its disadvantages. It is impossible to keep analogue recordings at the same level of quality as they were recorded. Tape degrades over the years, making the trebles less audible and noise more apparent. Vinyl also degrades and it needs a form of RIAA-correction to restore the original low frequencies.
However, the biggest drawback to analogue is the relatively high range of available dynamics in the digital domain. A 24 bit PCM recording can have a possible dynamic range of 144 dB above the noise floor while an LP only reaches 70 dB above the noise floor. Also the noise floor is lower in the digital domain even when it’s compared to a fresh tape recording. Therefore, a tape recording is always slightly compressed in the dynamic range due to these characteristics.
But why do we like the analogue sound so much? Because the degrading of the physical carrier, the trebles are less audible. Because of the reduced trebles, the lower frequencies stand out a bit more making the sound bigger, warmer and less clinical. Besides of this, analogue recording often feature a small amount of distortion. Distortion adds overtones to the original audio which creates a fuller spectrum, resulting in a warmer sound.
Analogue sound is obviously not possible on a download site. However, DSD is one of the most ‘analogue sounding’ digital formats. The nature of DSD – high sample rate but a small bit rate – and the use of Delta-Sigma modulation (a form of Pulse Width Modulation) instead of PCM makes DSD sounds very analogue.