The Audio Precision AUX-0025 Switching Amplifier Measurement Filter is a dual channel multi-pole LRC passive filter that provides the necessary attenuation of out-of-band signals and reduces the steepness of the fast switching edges. The AUX-0025 is a two-channel device that can be used with balanced or unbalanced amplifiers or analyzers.
The input connectors replicate the input connectors found on Audio Precision analyzers: XLR female jacks and banana jacks. The output connectors are XLR male plugs. Since loading capacitance is of concern, two short XLR male to XLR female cables are included to facilitate connection to the analyzer. For convenience, these cables are color-coded.
A passive design is also necessary to handle the wide dynamic range of signals that are normally presented to an analyzer. Any active filter has a limited amplitude range of operation. Thus, an active design would require an input attenuator and variable gain to accommodate the wide range of possible signal levels to be analyzed. Including such capability in an active design would be virtually duplicating the front end of the analyzer, an impractical approach from both cost and application points of view.
Audio Precision AUX-0025 Specs
|Number of Channels
||± 0.05 dB, 20 Hz to 20 kHz
||Typically 0.05 dB
|High Frequency Rejection
||Typically >50 dB, 250 kHz to 20 MHz
||±200 Vpk; 140 Vrms, 20 Hz to 5 kHz,
decreasing to 90 Vrms at 20 kHz
||> 90 dB at 20 kHz
||< –110 dB harmonic (measured at 70 Vpp, 1 kHz)
|< –100 dB IMD (at 70 Vpp with 18 kHz and 20 kHz dual tone test signal)