PassLabs Aleph L Owners manual

Pass Laboratories

Aleph L Owner's Manual

The Aleph L is a single ended Class A audio preamplifier combining new design thought
applied to traditional topology and the experience of twenty five years of amplifier design.

This preamplifier flows from a commitment to create the best sounding product: a simple
circuit with the most natural characteristic. The Aleph L integrates discrete Mosfet gain
devices and single ended Class A operation in a simple active/passive topology in order to
deliver the most natural sound possible. The Aleph L absolutely minimizes the number of
components in the signal path, and uses these only when necessary.

Unique to this preamp, patent pending, is a volume level control which combines the best
qualities of a passive attenuator and active gain circuitry:

At the 3 o’clock volume control position, the Aleph L offers a direct path from input to output.
The only component in the signal path is wire and switch contacts.

At positions below 3 o’clock, the volume control functions as a precision passive attenuator
using discrete resistor ladders.

Above 3 o’clock, active gain is added to the output signal in 2 decibel increments, for a
maximum of 10 dB.

As a result, you suffer the effects of active circuitry only when additional gain is necessary.
The Aleph L pushes the edge of the art in exploring how much subjective quality is

obtainable with a new but very elementary gain stage. The real goal is subjectively realistic
and natural sound, and the Aleph L achieves this without sacrificing objective measured
performance.

A very few people are involved in the production of this product. I supervise all phases of
the construction, and I test and listen to each preamplifier myself. If you have questions,
comments, or problems, please feel free to contact me directly.

Thank you for purchasing this preamplifier. It is my sincere hope that you will enjoy its sound
as much as I do.

_________________________________
Nelson Pass

Serial # ____________________

Date: ____________________

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