Pass Labs has introduced the Xs-300 and Xs–150 Amplifiers, first entries in a new generation of Xs Series amplifiers, at CES 2012.
Pass Labs' Xs-300 Amplifier.
The new amps are designed to measure well objectively, and sound subjectively as well as they measure, the company says.
The Xs-300 and Xs–150 Amplifiers are monoblock models delivering 300 and 150 watts, respectively. Both models employ double-stacked chassis, with the power supply and current source in one chassis and the input and main output stage in the other chassis. The separate power supplies enable a number of benefits, including lower electromagnetic noise, twice as much storage capacitance as earlier Pass Labs amps, banks of high-speed/soft-recovery rectifiers, improved high-frequency noise filters, bigger and better transformers, improved passive decoupling, massive heat sinks, and lower standby currents.
The Xs Series has been three years in development. The first year, Pass Labs settled on the power supply and physical package. The second year, Pass Labs finalized the output stage and front end. The third year, the company refined the front end and the biasing of the output stage.
In the process, Pass Labs applied a number of new refinements, including adjusting the values for push-pull Class A biasing and the amount of single-ended bias in the output stage. It also significantly increased the single-ended bias in the output stage over earlier Pass Labs amplifiers. Pass Labs also installed sturdy output stage transistors, with a combined capacity well over 10 KW, and massive heat sink assemblies capable of 2 KW all day long.