Sound engineers engage in heated debate about the merits of analogue recording over digital recording. Each recording method has its own advantages and much of the opinion on the final result is based on personal preference.
Aiming for Excellence
Despite efforts by sound engineers to extract the perfect audio experience from a performance, their endeavours are often wasted regarding levels of excellence as perceived by the public. The listening experience is dependent on several factors. At an audio performance, whether indoors or outdoors, no two people will hear a performance in the same way because of their relative position, their height in amongst a crowd, and how well the speakers project the sounds. When they listen to a recording, the quality of the listening device will have an impact on the audio experience. The ideal conditions in which to experience the audio recording would be through quality headphones, in a room with no vibrations or ambient noise and while sitting comfortably to be in the mood to accept the sounds. Even then, people will experience listening in their own ways and react to their own preferences regardless of the audio quality on the recording. It seems, then, that the end user is not so worried about the way the sounds were recorded and neither can they differentiate significant differences beyond personal penchant.
Where to Find Analogue and Digital Recordings
Analogue recordings are essentially sounds on playback media such as magnetic tape and vinyl records. Digital recordings are most usually listened to on CD, mini disc, DVD, mp3 players or via DAW (digital audio workstation) sequencers if working on a personal computer instead of a professional studio.
Listeners Want Perfection with Imperfections
Once digital recording matured to match the experience of analogue recording it became apparent that they produced differently perceived sounds. Digital recordings are known for their pristine collection of audio but in that clean assembly the sounds have become sterile. When compared to analogue recordings with their retained inherent distortions that appeal to the ear and transmit a warmth which digital recording cannot recreate without some creative manipulation, the two systems benefit from cross-over technology for the best sound experience. A digital recording could exist and be stored in a cyber-cloud whereas analogue recording always has a hard copy either in tape or playing record format.
Picture Sounds in Waves
Sound can be effectively represented as a graphical representation of an analogue wave. When sound is captured, ostensibly it is the air pressure change that has been caught. These pressure changes are what the ear experiences. A microphone is required in order to translate the air pressure change into a minor electrical voltage which then becomes the constant exemplification of the sound. Analogue recording is a direct reference to the term used to describe the sound when it remains the same and is therefore analogous; it has a corresponding function though the origins may differ.
Trapping the Sound on Screen
Digital representation displays the same sound via myriad tiny snapshots. These exceptionally fast snapshots are known as samples. The number of snapshots per second taken by the digital system is the sample rate. A digital recording’s quality is dependent upon two factors: the frequency of taking a sound snapshot and focus sharpness of the snapshot, the bit depth. Bandwidth is an area full of technical argument, but for a professional sound engineer working at 48 kHz (above the levels suggested by algorithms for optimum effect) takes 48,000 audio snapshots per second of the audio and at a bit depth of 24 is a fair compromise between audio quality and its usability.
Conversion from Analogue to Digital
To get an analogue signal from an analogue microphone to a computer, it requires conversion to digital information. This is achieved through an analogue-digital converter (ADC). The conversion used to subsequently produce the digital recording from the analogue input will utilise the sample rate on a linear setting. If sample rate is reduced by using fewer sound snapshots, subjectively perceived brightness level of a sound is reduced and its quality degrades. Almost like stop start frames in photographs, something is lost between shots. In music it is sparkle and ambience. Any bit depth reduction soon displays degradation as unpleasant distortion, with a brittle edge to the sound in unwanted noise that creeps in, similar to a photograph suffering from a grainy image. Hisses and fuzzy sounds spit and fizzle in an ugly fashion.
Superior Storage and Retrieval with Digital Recordings
Storing sound as a digital signal, a series of numbers, makes it easy to duplicate, transfer, shape, and store. An analogue signal does not fare so well once it has been recorded. Each time it is copied, its quality diminishes. This is partly due to the physical elements it encounters each time it is played which strangely contribute to that analogue warmth so sought after. A digital recording, in theory, will not experience any quality deterioration.
Purists and perfectionists will argue cases for each side but as digital technology becomes even more sensitive it can better manipulate the inherent parts that are missing from an analogue recording and produce a long-lasting, excellent sound reproduction to please most ears.
The Background Sounds of Analogue Recordings
The record head on a tape deck may cause hysteresis and saturation with analogue recordings. Added bias created by countering with extremely high frequency helps restore balance in linearising the audio. It is a similar attempt at rectifying problems such as dither, as experienced by digital recorders. Several problems can interfere with analogue recording because of the materials, the physical response of sound to those materials, and harmonic distortion created from electronic-influenced equipment. Pre-emphasis requires its own careful handling to avoid random noise or distortion, and even when critically damped, it may retain some residual resonance from the process. Saturation compression and self-erasure are other factors a sound engineer needs to attend to when dealing with an analogue recording machine. Side-bands and transient dynamics, such as drum beats, also require close attention.
With regard to harmonic distortion, changing the shape of the waveform is bound to occur in an analogue recording system. The waveform correlates with even or odd-order multiples of the source frequency with even numbered harmonics resulting in smoother sound and odd numbered harmonics exaggerating grungy sound. Either of the distortions might be desired elements depending on the overall effect required to suit the sound experience.
Valves, magnetised heads and solid state circuits, parts of the input machinery, each present their own influence or print on the audio output. Even the type of tape used will determine how much overdrive might result in a recording.
Simply put, vacuum tubes (or valves/tubes), pass current from anode to cathode. From the cathode, where the current is heated by the valve filament, an electron stream of electrons is passed on. Voltage determines the amount of current flowing from cathode to anode. There may be more than one grid. The three-terminal triode has anode, cathode, and control grid. The four-terminal tetrode has a screen grid as an extra grid and a five-terminal pentode also includes a suppressor grid. Tetrode and pentode valves’ extra grids facilitate the achievement of higher gains and higher radio frequency operation.
Getting the Best of Both Worlds
The numerous physical influences on an analogue recorder, though they may be reduced and smoothed right down to minimise distortion in the best systems, still leave their mark. Whether this mark is good or bad depends on the listener. A sound engineer seeking consistency may have many things to contend with for a quality analogue audio recording.
A digital recording system, though to some it may sanitise the sound beyond expectations, does deliver more easily monitored and manipulated audio output levels. Software plug-ins go some way to recreate the organic experience with its inherent distortion contributions through various emulations for guitar, tape and analogue gear.
How to Find Digital or Analogue Recorders on eBay
When reading the eBay home page, look to the left and select Musical Instruments. Within that category, locate Pro Audio Equipment and expand the options. Choose Recorders and on the new page displayed, select whichever preference suits, either Analogue or Digital. If preferred, type directly into the search box on any eBay page and the site will return current listings for the best match to the key words used.
The quality of materials used, how the unit is constructed and the amount of bandwidth frequency a recorder can manipulate will all affect the performance of the recording system, whether analogue or digital. The end result and what it is used for may influence a purchase decision. Creating a fabulous analogue recording with all its warmth and ambience will require using an analogue recording system. Keeping that quality recording in a format that will survive frequent playing will require it being transferred to a digital recording. Losses occur on both sides once the original recording is either played or remastered and compromise is a personal choice. Immediate degradation takes place on an analogue recording because of the physical limitations and a digital recording, depending on the sensitivity of the equipment and expertise of the operator, may lose some integrity.