Analoge Audio Flashcards
Analogue tape is based on?
Magnetism
What do both poles of a magnetic contain?
Ferrous materials
What are ferrous materials
Those that contain iron. Non ferrous materials do not contain iron
What are some ferrous materials
Mild steel
Carbon steel
Stainless steel
Cast iron
Wrought iron
What do the particles in tape contain?
Iron content
The heads which record onto iron tape use? And how do they work?
An electro magnet.
They create current flowing through a wire which generates a magnetic field
How can you increase the strength of a tape heads electromagnetic field
By increasing the number of coil wraps, and wrapping it around a ferrous material
What is the definition of analogue?
Essentially means the same, comparable in certain respects
What is the analogue signal flow?
Record - Syn - Repro
What does each analogue signal flow stage contain once it enters the input level of the machine?
A level, Hi freq and a bias control
What is Bias
A high frequency tone which is added and then filtered out to create additional strength to the signal. Without bias the signal has a non-linear response which means more noise and less signal strength
What does over biasing lead to?
Reduced high frequencies and a darker character
What is the record head
a coil wrapped around a magnet, creating a magnetic field which is printed onto the tape. Done by tiny filaments on the tape becoming magnetised by the signal. The reverse happens on the playback head (reproduce head).
what happens at the playback head (repro head)
the magnetic particles pass through the repro head and playback occurs. The reporo head filters out the bias and sends out particles as voltage, playing back the recorded material
What is the dynamic range of tape
tape has lower dynamic range than digital. Lowest level of tape determined by noise floor, and the top level is determined by the strength that the tape can handle/ the saturation of the tape
What is tape saturation
saturation in small amounts acts as compression and can be pleasing to the ear
What are test/reference tapes
they are needed to align the tape machine and set meters
How to calibration tapes work
they send in a know level for you to set your tape level, used to make sure zero is the right level.
what is the unit of magnetic strength
nanowbers per meter (nWb/meter)
what is the original tape stanrd magnetic strength
185 nWb/meter at 700Hz
What are multi track tape tracks seperated by
Guard bands
differences between 15 and 30 seconds per inch
slower tape means longer record time
30 inches offers lower lower noise and more headroom
15 inches has a smoother low end
recording onto tape adds a?
eq curve. tape machines have built in eq compensation to reduce hiss.
machines eq should be verified before playback and record. EQ curves can be switched on tape machines
what is the NAB eq curve
USA standard equalisation curve at 7.5 and 15 inches per second. later referred ti as IEC2
