VA measures total harmonic distortion, THD+N and the individual harmonic content of a signal. It can compensate for the residual distortion of the acquisition chain and automate measurements across a wide frequency range.
Single-frequency measurement
The analyser identifies the fundamental and evaluates the energy associated with its harmonics. Results can be expressed as THD or THD+N, while the spectrum remains available for inspection of individual products and the noise floor.
Automatic distortion sweep
VA can coordinate the function generator and analyser to repeat the distortion measurement at a sequence of frequencies. This produces a distortion-versus-frequency curve for amplifiers and other audio devices without requiring the operator to retune and record every point manually.
Nuova Elettronica project
A dedicated interface for distortion measurements was presented in Nuova Elettronica issue 238 (kit LX1729). The article explains the practical measurement arrangement and the hardware intended to extend VA’s capabilities.