D'Agostino's Second-Generation Progression Amplifiers
aunched in 2016, Dan D'Agostino Master Audio's Progression electronics were offered as less expensive alternatives to the company's Momentum models. D'Agostino has redesigned the Progression amplifiers, with the new M550 mono ($44,950 per pair) and S350 stereo ($29,950) models taking advantage of advancements in technology and circuit concepts used for the company's flagship Relentless monoblocks. Both amplifiers employ 48 output transistors powered by a nearly 2000VA power-supply transformer and 100,000 microfarads of power-supply capacitance. Improvements include a new heat-sink design whose greater cooling allows for increased power: 550 watts into 8 ohms, doubling to 1100 watts into 4 ohms and again to 2200 watts into 2 ohms for the M550; 350Wpc into 8 ohms and then doubling to 700 and 1400 watts into 4 and 2 ohms, respectively, for the S350. Both amps use a new power transistor in their upgraded output stage. First used in the Relentless mono amplifier, this transistor extends high-frequency response, increases power handling by a factor of four and features tighter-tolerance gain matching between complementary pairs. Coupling the new output device to the new heat sink allows an increase in operating bias, which has correspondingly increased the class-A operating range of the amplifiers -- to 70 watts for the Progression M550 and 45 watts for the Progression S350. The new amplifiers also have major revisions to their
input topology, which improves their distortion, signal-to-noise ratio, channel
separation, and bandwidth measurements. The new transistors handle six times the power of
the previous transistors, and new DC coupling circuitry has improved low-frequency
performance and extended the bandwidth of the amplifiers. According to D'Agostino, the new
input topology together with the output stage "has improved the dynamic impact,
detail retrieval, and spatial integrity of the amplifiers’ playback." |
