D'Agostino Progression Preamplifier/Stereo pre/power amplifier Lab Report

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.


Dynamic power output versus distortion into 8ohm (black trace), 4ohm (red), 2ohm (blue) and 1ohm (green) speaker loads. Maximum current 47.9A


THD vs. extended freq for Progression Preamp (1V out, black trace) vs. Stereo (10W/8ohm, red)

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

D’Agostino LLC
Connecticut, USA
Supplied by: Absolute Sounds Ltd
0208 971 3909