Pre/Power Amplifiers

While our inside shot reveals clear differences in the design of this Progression Preamp versus the more sophisticated Momentum Preamp [HFN Nov ’13], there are still clear parallels in their engineering targets. For example, the Progression Preamp has the same extended response (within ±0.1dB out to 100kHz) and there’s also that broad subsonic bass boost amounting to +0.45dB/20Hz and +0.95dB/5Hz. Distortion remains impressively consistent with frequency but is even lower here from 0.00065-0.00085% (Momentum) to 0.0005-0.0007% (Progression) across 20Hz-20kHz (0dBV). Overall gain is about 1.7dB higher at +9.8dB and the overall A-wtd S/N ratio wider still at 99.5dB (vs. 96.0dB) re. 0dBV.

The partnering Progression Stereo is significantly beefier than the Momentum Stereo [HFN Aug ’12], behaving like a ‘half power’ version of the (bridged) Progression Mono [HFN Jun ’17]. Its 300W/600W 8/4ohm power rating works out as 2x325W and 2x575W in practice although that massive PSU will sustain peaks of 365W, 690W, 1.33kW and 2.29kW into 8, 4, 2 and 1ohm loads under dynamic conditions at <1% THD [see Graph 1]. Like other D’Agostino power amps, the Progression Stereo is neither super-quiet (the A-wtd S/N is just under 80dB re. 0dBW) nor very low in distortion. Of more importance, arguably, is the control exercised over this distortion – held between 0.02-0.07% from 1-100W through the midrange and a similarly consistent 0.04-0.07% over the full (20Hz-20kHz) audio band [see red trace, Graph 2]. Output impedance is held to 0.17ohm from 20Hz-10kHz and the response flat from near-DC to –0.12dB/20kHz and –1.6dB/100kHz. PM

Power output (<1% THD, 8/4ohm): 325W / 575W
Dynamic power (<1% THD, 8/4/2/1ohm): 365W / 690W / 1325W / 2290W
Output imp. (20Hz–20kHz, pre/power): 39ohm / 0.17–0.19ohm
Freq. resp. (20Hz–100kHz, pre/power): +0.45 to –0.13dB / +0.0 to –1.6dB
Input sensitivity (for 0dBV/0dBW): 322mV (pre) / 181mV (power)
A-wtd S/N ratio (re. 0dBV/0dBW): 99.5dB (pre) / 79.6dB (power)
Distortion (20Hz-20kHz, 1V/10W): 0.0005–0.0007%/0.040–0.071%
Power consump. (pre/idle/rated o/p): 33W / 113W/970W
Dimensions (WHD, Pre/Power): 450x108x300/457x190x508mm
Price (pre/power): £24,998/£24,998