Constellation Audio Inspiration Mono 1.0 Power Amplifier Lab Report

Lab Report

Ordinarily when a stereo amplifier is bridged or BTL'd to supply twice the volts into a mono channel, power output increases into 8 and 4ohm loads but typically decreases into lower impedances due to a shortfall in current. Not so here for the Constellation Audio Mono 1.0 not only smashes its 400W/8ohm and 800W/4ohm specification with 590W and 990W (<1% THD), respectively, but it's also freed of the electronic protection that limited the Stereo's output to just 420W/1ohm [HFN Jul '15]. In practice then, under dynamic conditions the Mono 1.0 will sustain 690W, 1277W, 2165W and a full 2850W into 8, 4, 2 and 1ohm loads, respectively, for 10msec/<1% THD [see Graph 1, below]. With a 'clean' current reserve of over 53A, these monoblocks will drive any likely partnering speaker with ease.

Output impedance is a uniform 0.025-0.035ohm (20Hz-20kHz), increasing thereafter to 0.19ohm/100kHz, while the response into 8ohm is flat to –0.7dB/100kHz but (like the Stereo, but unlike the Centaur, HFN Jul '13] rolls away to –2.5dB/20Hz and –6dB/10Hz in the deep/subsonic bass. The 86.7dB A-wtd S/N (re. 0dBW) is some 5dB shy of the Stereo and distortion is very slightly higher, albeit following a more progressive trend from 0.00095%/1W to 0.0035%/10W, 0.033%/100W and 0.047% at the rated 400W/8ohm (all 1kHz). Versus frequency there is a marked difference between 'Balanced' mode, where THD is higher at low frequencies from 0.05%/5Hz to 0.007%/20Hz and 0.0038%/100Hz [see red trace, Graph 2] versus 'Direct' mode where THD is a 'flat' 0.0015-0.005% through bass and midrange black trace, Graph 2]. Both modes coalesce at 0.02%/20kHz and 0.06%/40kHz. See boxout, p59 for more on these options. PM


Dynamic power output versus distortion into 8ohm (black trace), 4ohm (red), 2ohm (blue) and 1ohm (green) speaker loads. Max. current is 53.4A


Distortion vs. frequency from 5Hz-40kHz re. 10W/8ohm (black, Direct; red, Balanced mode)

Power output (<1% THD, 8/4ohm) 590W / 990W
Dynamic power (<1% THD, 8/4/2/1ohm) 690W / 1.28kW / 2.17kW / 2.85kW
Output imp. (20Hz–20kHz/100kHz) 0.025–0.035ohm / 0.19ohm
Freq. resp. (20Hz–20kHz/100kHz) –2.5dB to –0.05dB/–0.65dB
Input sensitivity (for 0dBW/400W) 155mV / 3115mV (Balanced)
A-wtd S/N ratio (re. 0dBW/400W) 86.7dB / 112.7dB (Balanced)
Distortion (20Hz-20kHz, 10W/8ohm) 0.0035–0.043% (Balanced)
Power consumption (Idle/Rated o/p) 130W / 720W
Dimensions (WHD) / Weight 432x216x483mm / 36kg
Price £12,998 each

Constellation Audio
Newbury Park, CA, USA
Supplied by: Absolute Sounds Ltd
0208 971 3909