BNO Acoustics YM-44: VCA

Abbreviation for Voltage Controlled Amplifier (an amplifier that will change gain according to the level of control voltage sent to it).

BNO Acoustics QS-4: Repeat Echo
An echo effect caused by discrete repeats of a program source by using a long delay time and feedback on a delay line. Also called Space Echo.

BNO Acoustics LK-61: Test Tape
1) A less formal name for Alignment Calibration Tape (a test tape with tones of various frequencies all precisely recorded at a specified magnetic recording level used for tape machine alignment).
2) One of a few initial tapes made with high-speed duplication, and is listened to for approving the quality before production copies are made in volume.

BNO Acoustics GT-60: Volume Envelope
How a musical instrument sounding a pitch changes in volume over time.

Pressure Operated Microphone
A term meaning the same thing as the term Pressure Microphone. See the preceding entry.

Foldback
A European term for the signal sent to the stage monitors in a live performance.

PCM
An abbreviation for the term Pulse Code Modulation (the use of amplitude pulses in magnetic tape to record the digital information bits of digital audio).