BRAND: Pass Labs
SERIES: HPA-1 Power amplifiers
TYPE: Power Amplifier, Lifestyle
Pass Laboratories, Inc. was founded in 1991 by Nelson Pass. Operating out of his shop at home, Pass developed prototypes of a single-ended Class A amplifier design. At the same time, he and Mike Burley were constructing an in-house machine shop with three home-built CNC milling machines with which to produce the amplifiers when the design was finished.
OVERVIEW
The first product, the Aleph 0, shipped in 1992. It was a mono-block design rated at 70 watts into 8 ohms, and was unique in using three gain stages of power Mosfets including a push-pull output stage biased by a big constant current source. The amplifier operated as single-ended Class A up to its 70 watt rating and in push pull Class A at higher wattage. The amplifier was highly acclaimed, and was called the “Amplifier of the Decade” in Stereophile magazine.
At this time, Nelson hired his next-door neighbor, Elena Tong, to help with producing the amplifiers, and she manages much of the company to this day.
A stereo version called the Aleph 0s followed after, along with a preamp called the Aleph P. A larger version of the Aleph 0 called the Aleph 1 shipped the following year, and was a mono-block rated at 150 watts.
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TECHNICAL SPECIFICATIONS
Gain (dB)
8 dB
Power Consumption(W)
6 Output
Power into 20 ohms
3500 mW
Output Power into 300 ohms
200 mW
Frequency Response 10hz -100k
-1 dB
THD + Noise
< 0.005 at 1V out
Input Impedance
50K Ohm
Output Impedance
< 2 ohms
Dimensions (W x H x D)
4.5 x 11 x 13 nich
Unit Weight (LBS)
14
