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Equipment Measurements

March 2005

Anthem Statement P2 Stereo Amplifier: Measurements

All amplifier measurements are performed independently by BHK Labs. Please click to learn more about how we test amplifiers there. All measurement data and graphical information displayed below are the property of SoundStage! and Schneider Publishing Inc. Reproduction in any format is not permitted.

Additional Data
  • Measurements were made with 120V AC line voltage with both channels driven, driving the unbalanced inputs unless otherwise noted.
  • Gain: 28.3x, 29dB.
  • Output noise, 8-ohm load, unbalanced input, 1k-ohm input termination: wideband 0.270mV, -80.4dBW; A weighted 0.050mV, -95.0dBW.
  • Output noise, 8-ohm load, balanced input, 600-ohm input termination: wideband 0.205mV, -82.8dBW; A weighted 0.042mV, -96.6dBW.
  • AC line current draw at idle: 0.9A.
  • Output impedance at 50Hz: 0.0072 ohms.
  • This amplifier does not invert polarity.
Measurements Summary

Power output with 1kHz test signal

  • 8-ohm load at 1% THD: 373W

  • 4-ohm load at 1% THD: 609W

General

The Anthem Statement P2 stereo amplifier is a high-power solid-state design with typically wide bandwidth and very low output impedance.

Chart 1 shows the frequency response of the amp with varying loads. As can be seen, the output impedance, as judged by the closeness of spacing between the curves of open circuit, 8-ohm, and 4-ohm loading, is quite low. The variation with the NHT dummy load in the audio range is negligible.

Chart 2 illustrates how total harmonic distortion plus noise vs. power varies for 1kHz and SMPTE IM test signals and amplifier output load. As can be seen, attainable power is greater for the 4-ohm load as is usual for most power amplifiers.

Total harmonic distortion plus noise as a function of frequency at several different power levels is plotted in Chart 3. Amount of rise in distortion at high frequencies is fairly pronounced and is similar to that of many amplifiers measured.

Damping factor vs. frequency is shown in Chart 4 and is unusually high.

A spectrum of the harmonic distortion and noise residue is plotted in Chart 5. The magnitude of the AC-line harmonics is low and typical of many of the amplifiers measured at BHK Labs. The test signal harmonics are both even and odd harmonic with the higher-order harmonics smoothly declining with frequency.

Chart 1 - Frequency Response of Output Voltage as a Function of Output Loading


Red line: open circuit
Magenta line: 8-ohm load
Blue line: 4-ohm load

Chart 2 - Distortion as a Function of Power Output and Output Loading


(line up at 20W to determine lines)
Top line: 4-ohm SMPTE IM
Second line: 8-ohm SMPTE IM
Third line: 4-ohm THD+N
Bottom line: 8-ohm THD+N

Chart 3 - Distortion as a Function of Power Output and Frequency


4-ohm output loading
Green line: 500W
Blue line: 70W
Magenta line: 20W
Red line: 2W

Chart 4 - Damping Factor as a Function of Frequency


Damping factor = output impedance divided into 8

Chart 5 - Distortion and Noise Spectrum


1kHz signal at 10W into a 4-ohm load

 

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