Transients Making or breaking connections while a circuit is playing, may result in a sharp change in signal. This is known as a transient. Often these go unnoticed, unless the connection is in-line with an audio device. Special care should be taken at high volume through a SPDF port. The pin's letter represents what sort of information is expected.
Capital letters mean continous data, lowercase letters mean a zero-crossing trigger.
A Amplitude, usually an input, always means multiplication. D Decay, Delay, used for filters, interpereted as a percentage. F Frequency, usually an input. L Left channel in a stereo field. M Midi Note, usually an input.