1) An electronic device capable of generating test tones at various frequencies for testing and trouble shooting applications. 2) An oscillator circuit in a synthesizer used to generate audio signals and tones similar in sound to various instruments.
1) A device, which puts out test tones at various frequencies to align a tape machine or for other testing purposes. 2) The circuits in a synthesizer that make the audio signal that is put out by the unit and which would be similar to the sound of an instrument.