The Aleph P is a single ended Class A audio preamplifier, the first produced by Pass Laboratories. It combines completely new design thought applied to a traditional topology and the experience of twenty five years of amplifier design. This manual applies to the second version of the Aleph P, which incorporated circuit improvements and remote control operation. This preamplifier flows from a commitment to create the best sounding product: a simple circuit with the most natural characteristic.
The Aleph P integrates power Mosfet devices and single ended Class A operation in a simple topology in order to deliver the most natural sound possible. The circuitry of the Aleph P breaks new ground in simplicity and performance. Each gain stage consists of a single Mosfet power transistor operated “common source” mode.
One such circuit amplifies each signal polarity of a balanced input signal, and their operation is inter-coupled to allow optimal operation with both balanced and unbalanced input signals while still providing balanced and unbalanced outputs. It retains the important simple singleended characteristic while operating either single-ended or balanced. It is unique in providing superior flexibility and performance with balanced and unbalanced inputs and outputs, converting one to the other as desired without switches or adapters.
The Aleph P absolutely minimizes the number of components in the signal path, and yet retains exemplary objective performance specifications. More importantly, it pushes the edge of the art in exploring how much subjective quality is obtainable with a new but very elementary gain stage. 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.
Gain 15 dB bal in / bal out 15 dB unbal in / bal out
9 dB bal in / unbal out 9 dB unbal in / unbal out
Freq. Response -3 dB @ 5 Hz -3 dB at > 100 kHz
Distortion < .1 % THD typically .01% @ 2 volts @ 1KHZ
Maximum Output 15 volts rms. bal out 8 volts rms. unbal out
Output Impedance 0 – 1000 ohms unbalanced
0 – 2000 ohms balanced
Input Impedance 10 kOhm unbalanced 20 kOhm balanced
CMRR typical -80 Db, 20-20 KHz
Crosstalk typical -90 dB, 20-20 KHz
Output Noise Noise floor < -120 dBV, 20-20 KHz
Power Consumption 25 watts
Dimensions 19 ” W x 11.5 “ D x 4″ H
Shipping Weight 35 lb.