Pre/Power Amplifiers

As the distinctive, fully balanced audio circuits of the Pictor/Taurus are ‘distilled’ from the Inspiration pre/power [HFN Jul ’15] and Virgo/Centaur [HFN Jul ’13] there are obvious parallels to their performance. The Pictor preamp still uses a rotary-encoded volume control (addressing a polysilicon resistor array) with an accuracy of –0.8dB over the top 10dB but a superior –0.4dB over a fuller 80dB range. It offers the same +26.5dB gain (balanced) and remarkably flat and extended response (+0/–0.09dB from 1Hz-100kHz) and while the 91dB A-wtd S/N ratio and 119ohm source impedance exactly match the Inspiration, distortion at 0.0004–0.0009% (re. 0dBV) is lower and a better match with the Virgo [black trace, Graph 2]. Distortion increases with preamp output above 1V (0.0009%) to 25V (1%), the latter voltage sufficient to drive any power amp on the hi-fi planet.

Constellation rates the new Taurus Stereo at 250W/8ohm – a specification demolished by the 2x415W/8ohm and 2x655W/4ohm measured here, increasing to 455W, 820W and 1.14kW into 8, 4 and 2ohm under dynamic conditions. In common with the Inspiration, output into 1ohm loads is limited [see Graph 1] but it’ll still drive any likely partnering speaker with ease. The uniform 0.033-0.045ohm (20Hz-20kHz) output impedance is also unchanged as is its response – still flat to –0.4dB/100kHz and (unlike the Centaur, but just like the Inspiration) rolled away to –2.1dB/20Hz and –10dB/10Hz in the deep/subsonic bass. The real advantage in the Taurus’s improved PSU is not in power output but in its impressively reduced noise – the A-wtd S/N here is 5dB better at 96dB (re. 0dBW) while THD [blue trace, Graph 2] is not dissimilar at 0.004-0.04% (20Hz-20kHz, 10W). PM

Power output (<1% THD, 8/4ohm): 415W / 665W
Dynamic power (<1% THD, 8/4/2/1ohm): 455W / 820W / 1.14kW / 580W
Output imp. (20Hz–20kHz, pre/power): 119ohm / 0.034–0.051ohm
Freq. resp. (20Hz–100kHz, pre/power): +0.0 to –0.09dB / –2.4 to –0.4dB
Input sensitivity (for 0dBV/0dBW): 48mV (pre) / 157mV (power)
A-wtd S/N ratio (re. 0dBV/0dBW): 91.0dB (pre) / 96.1dB (power)
Distortion (20Hz-20kHz, 1V/10W) : 0.0004–0.0009%/0.004–0.038%
Power consump. (pre/idle/rated o/p): 27W / 88W/940W
Dimensions (WHD Pre/Power): 432x133x381/476x297x603mm
Price (pre/power): £22,000/£24,000