Analogue Audio Flashcards
ferrous metals
mild steel
carbon steel
stainless steel
cast iron
wrought iron
DEF:
ferrous metals
both poles are magnetic and contain iron
non ferrous metals
aluminium
copper
brass
silver
lead
DEF:
non ferrous metals
do not contain iron
analogue signal flow
record –> sync –> repro
each stage has level, hi freq and bias controls
how is sound recorded to tape
particles in tape have some iront content, which is recorded onto with heads using an electromagnet that uses current flowing through a wire to generate a magnetic field.
strength of electromagnet coil can be increased by number of coil wraps. will be even stronger if wrapped around a ferrous metal
DEF:
bias (analogue audio)
a high frequency tone (40-150 kHz) on magnetic tape that adds strength to the audio signal and ensures a linear response at low levels. The bias and the original signal are mixed together and sent to the recording head and is later filtered out.
result of over biasing
reduced HF content creating a darker sound
DEF:
record head
an elecromagnet (coil wrapped around a magnet) which allows the signal to flow through creating a magnetic field. As the tape moved past the record head, tiny metal filaments on the tape become magnetised by the signal.
DEF:
playback head
head for analogue playback where the magnetic particles pass through the reproduction head, which filters out bias then send particles out as voltage, playing back recorded material
what does the reproduce (repro) head do?
passes signal through electronic controls (level, HF, and bias) to make the record level
dynamic range of tape
much lower than digital
lowest level determined by noise floor (cause by particles through the head)
top level is determined by the saturation of the tape (which acts as compression and can be musical in small amounts)
how do you make sure zero is at the right level for meters and tape machines
calibration tapes send in a known reference level for that specific brand of tape and you calibrate accordingly
example of mastering audio tape
Ampex 406
EMI tape formulas
888 - early 60s - lofi and granier w/ more distortion 1-8kHz
811 - mid/late 60s - better HF response, slightly less distortion than 888
815 - flatter HF response, minimal colouration, less distortion than 811
