Loudspeakers

The closest ‘first generation’ Constellation power amp to the Revelation 2 is the Taurus Stereo [HFN Dec ’17] which, though rated at a lower 250W/8ohm still achieved 455W, 820W and 1.14kW into 8, 4 and 2ohm under dynamic conditions. The new Revelation 2 Stereo is rated at 300W/8ohm and while it delivers a higher 2x475W/8ohm and 2x805W/4ohm continuously, the tight regulation of the new switchmode PSU means that power under dynamic conditions is actually fractionally less, and almost identical to the Taurus at 460W, 795W and 1.1kW into 8, 4 and 2ohm loads. Again, maximum power/current is limited to 305W/1ohm [see Graph 1, below] though it’ll still drive any likely partnering speaker with ease. The distortion profile is largely unchanged – a function of the bridged/NPN power modules – from a minimum of 0.0018%/1W to 0.003%/10W, rising after 40W to 0.005%/100W and 0.065% at the rated 300W (all re. 1kHz/8ohm). Versus frequency there’s an increase from 0.003-0.025% between 1kHz-20kHz, a trend that continues until it levels off at higher power [see red trace, Graph 2].

The uniform 0.033-0.037ohm output impedance is actually slightly ‘flatter’ than in the Taurus but the response is not, falling here to –2.6dB/100kHz in place of the Taurus’s –0.4dB/100kHz [see boxout]. More importantly, from a listening standpoint, Constellation has ‘tweaked’ the DC servo – and hence group delay – of this amplifier which now has a –3dB point at 3Hz instead of 18Hz. Noise, however, is higher in the Revelation 2 Stereo than it was in the Taurus Stereo – this is an increase in ‘white’ noise rather than hum – leading to an A-wtd S/N that’s some 10dB behind at 85dB (re. 0dBW). PM