Pass Labs Aleph 2 Amplifiers

Pass Labs Aleph 2 Class A Monoblocks (set of two).
Accompanying pics show the amps (in close-up) and well as the system in which they are currently installed (Wadia CD transport feeding Pass Labs Aleph P pre-amp, connected to the Pass Labs Aleph 2 monoblocks, powering B&W Matrix 802 Series 3 Speakers).

From Pass Labs: "The Aleph 2 integrates power Mosfet devices and pure single ended Class A operation in a simple two-gain-stage topology with the sole purpose of recreating subjectively natural sound.

The Aleph 2 is unique in a number of ways:

Unlike the earlier Aleph amplifiers, it operates in pure single-ended mode over its entire operating region, and does not incorporate a “pull” stage for additional current beyond its bias point. When the single-ended output Mosfets (six in parallel) reach cutoff, the amplifier clips.

Most amplifiers on the market have between five and seven gain stages in series between the input and the output. The Aleph 2 has but two, and enjoys a very direct path from input to output, further enhancing the purity of the circuit and the resulting sound. Earlier Aleph amplifiers have three gain stages.

The output stage of the Aleph 2 is a unique blend of traditional design and innovation addressing the unique requirements of loudspeakers. Previous methods of loading the output stage have used networks consisting of resistors, coils, transformers, and active current sources, all of which offer an optimal load line based on a resistive load. The Aleph 2 has a current source topology which optimizes performance for a wide range of impedance and reactance in the load, improving all aspects of performance into real loudspeakers. Pass Labs has a US patent pending on this output stage topology.

The Aleph 2 is unique in that there are no adjustments of any kind in the circuitry. There are no potentiometers to adjust. The operating parameters of bias currents and DC offset and so on are defined by physical constants, and will not go out of adjustment.

Most important, the Aleph 2 brings a new dimension to the recreation of subjective sonic reality. The amplifier delivers detail and subjective space rarely found in semiconductor circuits, coupled with the authority and clarity rarely found in tube amplifiers."

Power Output is 100 W/Ch into 8 Ohms; 200 W/Ch into 4 Ohms.