The AUX-0025 is an Amplifier from Audio Precision.
Features:
Two channel, 20 Hz to 20 kHz passband
Passive design for optimal performance
Custom inductors designed for power handling and minimizing low-frequency distortion
Flat response
Small insertion loss
Compatible with both balanced and unbalanced amplifiers and analyzers
Filter-to-analyzer cables included
Specifications:
Frequency Response: ±0.05 dB, 10 Hz to 20 kHz
Insertion loss: typically 0.05 dB
High Frequency Rejection: typically >50 dB, 250 kHz to 20 MHz
Maximum Input: ±200 Vpk [140 Vrms], dc to 7.5 kHz, decreasing to 75 Vpk [53 Vrms] from 20 kHz to 2 MHz
Interchannel Crosstalk: >90 dB at 20 kHz
Distortion: <–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; IMD components are at 2 kHz, 16 kHz, and 22 kHz)
Applications
Measurement of switching amplifiers
Measurement of analog signals with high amounts of out-of-band noise
The AUX-0025 is a two-channel passive filter, with a 20 Hz to 20 kHz passband. It is designed to be used with two-channel analyzers, including the APx555, APx52x Series and 2700 Series test systems.
The Audio Precision AUX-0025 switching amplifier measurement filters are designed to be inserted between the device under test and an analyzer input, to reduce out-of-band switching signal components before measurement. The filters use a passive design for optimal performance, with custom inductors designed for high power handling and minimal low-frequency distortion.
Manufacturers of power amplifiers are moving to switching designs (also called Class D or switch-mode) to make their designs (also called Class D or switch-mode) to make their conventional linear power amplifier designs. This technology has particular appeal in automotive and personal stereo applications where efficiency, low battery consumption, small size, and low cost are desired. However, amplifiers using this technology present new measurement challenges. The switching process adds fast edges at the switching frequency to the audio output signal. These fast edges are of no consequence to the typical load, a loud-speaker, but present a difficult signal for measurement instruments. The fast switching edges present high energy content and will introduce slew rate limiting when presented to the input stage of most measurement instruments. When stressed by these fast edges, the analyzer input amplifier will usually slew rate limit and will not be able to function effectively in its normal mode. Auto ranging will be affected and the signal under test will be misrepresented to the following measurement circuits. The result is that noise and distortion measurements of switching amplifiers with almost any analyzer without preconditioning will yield inaccurate and unpredictable results.
The solution to this problem is to precondition the signal before presentation to the analyzer. The way to do this is in the form of a low pass filter that will soften the fast edges while passing the primary audio signal intact. The best approach to this filter is a passive design, as it will handle the fast edges properly, is relatively low cost, and will not require power. A well-designed passive filter will also not compromise the audio signal passing through it by adding noise or distortion as an active design might.
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.
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.
The AUX-0025 is an Amplifier from Audio Precision.
Features:
- Two channel, 20 Hz to 20 kHz passband
- Passive design for optimal performance
- Custom inductors designed for power handling and minimizing low-frequency distortion
- Flat response
- Small insertion loss
- Compatible with both balanced and unbalanced amplifiers and analyzers
- Filter-to-analyzer cables included
Specifications:
- Frequency Response: ±0.05 dB, 10 Hz to 20 kHz
- Insertion loss: typically 0.05 dB
- High Frequency Rejection: typically >50 dB, 250 kHz to 20 MHz
- Maximum Input: ±200 Vpk [140 Vrms], dc to 7.5 kHz, decreasing to 75 Vpk [53 Vrms] from 20 kHz to 2 MHz
- Interchannel Crosstalk: >90 dB at 20 kHz
- Distortion: <–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; IMD components are at 2 kHz, 16 kHz, and 22 kHz)
Applications
- Measurement of switching amplifiers
- Measurement of analog signals with high amounts of out-of-band noise
The AUX-0025 is a two-channel passive filter, with a 20 Hz to 20 kHz passband. It is designed to be used with two-channel analyzers, including the APx555, APx52x Series and 2700 Series test systems.
The Audio Precision AUX-0025 switching amplifier measurement filters are designed to be inserted between the device under test and an analyzer input, to reduce out-of-band switching signal components before measurement. The filters use a passive design for optimal performance, with custom inductors designed for high power handling and minimal low-frequency distortion.
Manufacturers of power amplifiers are moving to switching designs (also called Class D or switch-mode) to make their designs (also called Class D or switch-mode) to make their conventional linear power amplifier designs. This technology has particular appeal in automotive and personal stereo applications where efficiency, low battery consumption, small size, and low cost are desired. However, amplifiers using this technology present new measurement challenges. The switching process adds fast edges at the switching frequency to the audio output signal. These fast edges are of no consequence to the typical load, a loud-speaker, but present a difficult signal for measurement instruments. The fast switching edges present high energy content and will introduce slew rate limiting when presented to the input stage of most measurement instruments. When stressed by these fast edges, the analyzer input amplifier will usually slew rate limit and will not be able to function effectively in its normal mode. Auto ranging will be affected and the signal under test will be misrepresented to the following measurement circuits. The result is that noise and distortion measurements of switching amplifiers with almost any analyzer without preconditioning will yield inaccurate and unpredictable results.
The solution to this problem is to precondition the signal before presentation to the analyzer. The way to do this is in the form of a low pass filter that will soften the fast edges while passing the primary audio signal intact. The best approach to this filter is a passive design, as it will handle the fast edges properly, is relatively low cost, and will not require power. A well-designed passive filter will also not compromise the audio signal passing through it by adding noise or distortion as an active design might.
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.
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.
