All amplifier measurements are performed independently by Warkwyn Associates. 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.

Notes: Measurements were made at 120V AC line voltage with both channels being driven (stereo mode). Measurements made on left channel through the balanced input for stereo and mono modes unless otherwise noted.

Power output (stereo mode)

  • Power output at 1% THD+N: 333.3W @ 8 ohms, 499.4W @ 4 ohms
  • Power output at 10% THD+N: 365.2W @ 8 ohms, 576.0W @ 4 ohms

Power output (mono mode)

  • Power output at 1% THD+N: 1200W @ 8 ohms, 1953W @ 4 ohms
  • Power output at 10% THD+N: 1453W @ 8 ohms, 2303W @ 4 ohms

Additional data

  • This amplifier does not invert polarity.
  • AC-line current draw at idle: 1.29A, 0.62PF, 98W
  • Gain at 1W at into 8 ohms at 1kHz, unbalanced and balanced inputs
    •      Stereo and mono modes: 39.9X, 32.0dB
  • Input sensitivity for 1W into 8 ohms, unbalanced and balanced inputs 
    •      Stereo and mono modes: 71.1mV
  • Output impedance @ 50Hz
    •      Stereo mode: 0.0093 ohm
    •      Mono mode: 0.0182 ohm
  • Input impedance @ 1kHz
    •      Stereo mode, unbalanced input: 8.58k ohms
    •      Stereo model, balanced input: 26.6k ohms
    •      Mono mode, unbalanced input: 5.33k ohms
    •      Mono mode, balanced input: 15.7k ohms
  • Output noise (stereo mode), 8-ohm load, unbalanced inputs terminated with 1k ohms, Lch/Rch
    •      Wideband: 0.133mV/0.142mV, -86.5dBW/-86.0dBW
    •      A weighted: 0.101mV/0.099mV, -88.9dBW/-89.1dBW
  • Output noise (stereo mode), 8-ohm load, balanced inputs terminated with 600 ohms, Lch/Rch
    •      Wideband: 0.129mV/0.138mV, -86.8dBW/-86.2dBW
    •      A weighted: 0.095mV/0.093mV, -89.5dBW/-89.6dBW
  • Output noise (mono mode), 8-ohm load, unbalanced inputs terminated with 1k ohms
    •      Wideband: 0.164mV, -84.7dBW
    •      A weighted: 0.121mV, -87.4dBW
  • Output noise (mono mode), 8-ohm load, balanced inputs terminated with 600 ohms
    •      Wideband: 0.160mV, -84.9dBW
    •      A weighted: 0.119mV, -87.5dBW

Measurements summary

All charts: A = stereo mode, B = mono mode.

Charts 1A and 1B show the frequency response of the Hegel H30 with different resistive loads. With loads of 4 and 8 ohms, there are small deviations in output response at 20kHz in both stereo and mono modes, but the dummy-speaker load shows very little deviation at 20kHz, which reflects real-world load conditions.

Charts 2A and 2B illustrate how total harmonic distortion plus noise (THD+N) vs. power varies for 1kHz and SMPTE IM test signals. The results show very low and uniform distortion levels in both modes until clipping is reached.

Charts 3A and 3B show THD+N as a function of frequency at several different power levels into 4 ohms. The high output power achieved in stereo and mono modes with low THD+N is admirable. (Note that the decrease in distortion above 10kHz in these charts is a result of a 22kHz cutoff filter, which helps to improve the accuracy of this test below 10kHz.)

Charts 4A and 4B show the H30’s damping factor vs. frequency. The result in mono mode is about half that in stereo mode, but has a similar shape.

Charts 5A and 5B show the spectrum of harmonic distortion and noise residue for a 10W, 1kHz test signal.

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

Chart 1A

Chart 1A

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

Chart 1B

Chart 1B

Mono mode
Red line = open circuit
Cyan line = 8-ohm load
Blue line = 4-ohm load
Magenta line = dummy-speaker load

Chart 2 - Distortion as a function of power output and output loading

Chart 2A

Chart 2A

Stereo mode
(Line up at 20W 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

Chart 2B

Mono mode
(Line up at 20W 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 3 - Distortion as a function of power output and frequency

Chart 3A

Chart 3A

Stereo mode, 22kHz cutoff filter
(4-ohm loading)
Cyan line = 2W
Green line = 20W
Blue line = 100W
Red line = 200W
Magenta line = 400W

Chart 3B

Chart 3B

Mono mode, 22kHz cutoff filter
(4-ohm loading)
Cyan line = 2W
Green line = 20W
Blue line = 600W
Red line = 1400W

Chart 4 - Damping factor as a function of frequency

Chart 4A

Chart 4A

Stereo mode
Damping factor = output impedance divided into 8

Chart 4B

Chart 4B

Mono mode
Damping factor = output impedance divided into 8

Chart 5 - Distortion and noise spectrum

Chart 5A

Chart 5A

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

Chart 5B

Chart 5B

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