Pre/Power Amplifiers

With 1000s of watts on tap, and a fully floating output that cannot be permitted to see a sniff of ground, the Relentless presents some special challenges for anyone intending to work up a full lab test. This is not a task for the inexperienced! But there are more subtle factors that need to be considered, in particular the impact of D'Agostino's low feedback scheme on performance as this mass of copper and aluminium very slowly heats up. When first taken out of standby, a 'cold' Relentless incurs some 0.006% distortion (1kHz/10W/8ohm) but over the first hour or so this reduces to 0.0035% [black trace, inset Graph] as the heatsinks gradually adapt to the 512W of idle power consumption.

Just leaving a pair of these amps powered-up draws as much from the wall as a one-bar electric heater, the chassis typically rising to 25oC over ambient (so about 45oC in a 20oC living space). After 24hrs the Relentless's thermal latency is almost entirely resolved, the linearity of its output stage maintained by sheer mass at a low 0.0015% distortion [red dotted trace, inset Graph].