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All amplifier measurements are performed independently by BHK Labs. All measurement data and graphical information displayed below are the property of the SoundStage! Network and Schneider Publishing Inc. Reproduction in any format is not permitted.

Note: Unless otherwise noted, measurements were made at 120V AC line voltage, using the balanced inputs, and with the left channel.

Power output (stereo mode) @ 1kHz

  • Power output at 1% THD+N: 414.8W @ 8 ohms, 665.9W @ 4 ohms
  • Power output at 10% THD+N: 510.0W @ 8 ohms, 800.0W @ 4 ohms

Power output (mono mode) @ 1kHz

  • Power output at 1% THD+N: 1328W @ 8 ohms
  • Power output at 10% THD+N: 1450W @ 8 ohms

Additional data

  • Input/output polarity: noninverting
  • AC-line current draw
    • Standby: 2.1W, 0.04A, 0.44PF
    • Operate: 267.0W, 3.1A, 0.72PF
  • Gain: output voltage divided by input voltage, 8-ohm load
    • Stereo mode, Lch/Rch
      • Balanced inputs: 28.04X, 29.0dB / 27.06X, 28.7dB
      • Unbalanced inputs: 28.35X, 29.1dB / 27.36X, 28.7dB
    • Mono mode
      • Balanced input: 59.94X, 34.8dB
      • Unbalanced input: 54.30X, 34.7dB
  • Input sensitivity for 1W output into 8 ohms
    • Stereo mode, Lch/Rch
      • Balanced inputs: 100.7mV / 104.5mV
      • Unbalanced inputs: 99.8mV / 103.4mV
    • Mono mode
      • Balanced input: 51.5mV
      • Unbalanced input: 52.1mV
  • Output impedance @ 50Hz
    • Stereo mode: 0.0033 ohm
    • Mono mode: 0.0065 ohm
  • Input impedance @ 1kHz
    • Stereo mode, Lch/Rch
      • Balanced inputs: 210k ohms / 219k ohms
      • Unbalanced inputs: 105k ohms / 109k ohms
    • Mono mode
      • Balanced input: 152k ohms
      • Unbalanced input: 78k ohms
  • Output noise (stereo mode), 8-ohm load, balanced inputs terminated with 600 ohms, Lch/Rch
    • Wideband: 337.2uV/323.5uV, -78.5dBW/-78.8dBW
    • A weighted: 133.1uV/97.9uV, -86.6dBW/-89.2dBW
  • Output noise (stereo mode), 8-ohm load, unbalanced inputs terminated with 1k ohms, Lch/Rch
    • Wideband: 333.3uV/325.4uV, 78.6dBW/-78.9dBW
    • A weighted: 130.1uV/97.9uV, -86.7dBW/-89.2dBW
  • Output noise (mono mode), 8-ohm load, balanced inputs terminated with 600 ohms
    • Wideband: 501.0uV, -73.0dBW
    • A weighted: 188.5uV, -83.5dBW
  • Output noise (mono mode), 8-ohm load, unbalanced inputs terminated with 1k ohms
    • Wideband: 498.3uV, -75.1dBW
    • A weighted: 190.7uV, -83.4dBW

Measurements summary

Parasound’s Halo JC 5 is one of the latest results of John Curl’s long-established expertise in power-amplifier design. Weighing a hefty 90 pounds, it’s a beautiful unit, impressive indeed.

The frequency responses for the Halo JC 5’s stereo and mono modes are plotted in Charts 1 and 1A. Notable are the smooth high-frequency rolloff and the good regulation with load changes. The greater rolloff in mono mode is essentially caused by the outputs of the two stereo channels in series into the loads.

The JC 5’s total harmonic distortion (THD) plus noise and SMPTE intermodulation distortion are shown in Charts 2A and 2B for, respectively, the stereo and mono modes. (In mono mode, the JC 5 is specified for 8-ohm loads.)

Charts 3A and 3B plot the Halo JC 5’s THD+N vs. frequency and power. The rise in high-frequency distortion is typical of most of the power amplifiers I test.

The Halo JC 5’s damping factor vs. frequency in stereo mode, plotted in Chart 4, is typical of solid-state amplifiers: high at low frequencies, and falling above a few hundred hertz. Not surprisingly, the result in mono mode (not shown) looked similar, but with about half the damping factor. Again, this is because, in mono mode, the output is the series output of the two stereo channels.

Chart 5, the spectrum of a 10W, 1kHz signal into 8 ohms, shows low amounts of signal harmonics, mainly the second and third harmonics -- a good thing for sound. Also visible, however, are large amounts of line-based hum harmonics; these are of high enough magnitude to contribute to the total harmonic measurement amount.

Chart 1 - Frequency response of output voltage as a function of output loading

Chart 1A - stereo mode

Chart 1A

Stereo mode
Red line = open circuit
Magenta line = 8-ohm load
Blue line = 4-ohm load

Chart 1B - mono mode

Chart 1B

Mono mode
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

Chart 2A - stereo mode

Chart 2A

Stereo mode
(Line up at 100W to determine lines)
Top line = 4-ohm SMPTE IM distortion
Second line = 8-ohm SMPTE IM distortion
Third line = 4-ohm THD+N
Bottom line = 8-ohm THD+N

Chart 2B - mono mode

Chart 2B

Mono mode
(Line up at 100W to determine lines)
Top line = 8-ohm SMPTE IM distortion
Second line = 8-ohm THD+N

Chart 3 - Distortion as a function of power output and frequency

Chart 3A - stereo mode

Chart 3A

Stereo mode
(4-ohm loading)
Red line = 1W
Magenta line = 10W
Blue line = 75W
Cyan line = 200W
Green line = 400W
Yellow line = 600W

Chart 3B - mono mode

Chart 3B

Stereo mode
(8-ohm loading)
Red line = 1W
Magenta line = 10W
Blue line = 100W
Cyan line = 600W
Green line = 1200W

Chart 4 - Damping factor as a function of frequency

Chart 4

Stereo mode
Damping factor = output impedance divided into 8

Chart 5 - Distortion and noise spectrum

chart5

Stereo mode
1kHz signal at 10W into an 8-ohm load

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