Pass Labs 1XA160.5 specification

XA160.5 Owner’s Manual

Nelson Pass has been designing audio electronics since about 1971, first with ESS (remember Heil transformers?), and then forming a new company, Threshold in 1975. Threshold pioneered the design of high power Class A power amplifiers and later, high power amplifiers using only local feedback (the Stasis series).

Pass sold Threshold and created Pass Laboratories in 1991, where he concentrated first on elevating single-ended Class A power amplifiers to new power levels and performance, the Aleph series.

Along the way he found the time to design successful lines of amplifiers for such companies as Adcom and Nakamichi, and has contributed approximately 60 designs (so far) to the public “Do-It- Yourself ” hobbyist community.

Over the years, Nelson Pass has made power, simplicity, and performance his design signature. The hardware tends to run heavy and hot, but elicits high performance and reliability from simple circuits with little or no negative feedback..

In 1998 Pass Labs released the X series of audio power amplifiers, based on the “SuperSymmetric” topology (U.S. Patent #5,376,899) which elicits high power and performance from simple circuits with minimal feedback.

The first X amplifier, the X1000 was intended as the premier example of the power of this principle, delivering 1000 watts rms into 8 ohms at low distortion. By itself of course, this is no miracle, but you have to consider that products with comparable performance have complicated circuits with as many as nine consecutive gain stages and lots and lots of negative feedback. The X1000 had only two stages and used only local feedback.

The difference was the unique balanced circuit topology in which circuit errors are replicated at both output terminals so as to cancel and disappear across the loudspeaker terminals. The high quality of the sound reflects both the low distortion and simplicity of the gain path.

The SuperSymmetric circuit consists of two identical matched circuits arranged like the wings of a butterfly, showing symmetry from left to right, and operating balanced to the loudspeaker. The amplified signal appears with opposing phase across the loudspeaker. Most of the distortion and noise appears in phase across the loudspeaker, and is not seen.

1XA160.5 specifications

Pass Labs, renowned for its high-performance amplifiers, has made waves with its 1XA160.5 power amplifier. This product epitomizes the brand's commitment to sonic excellence, technical sophistication, and exceptional build quality. Emphasizing a pure, uncolored sound, the 1XA160.5 offers audiophiles a window into the heart of their music.

At the core of the 1XA160.5 is its innovative single-ended Class A design. This architecture allows the amplifier to deliver a lush and natural sound characteristic, which is the hallmark of Pass Labs’ engineering philosophy. Being Class A means that the amplifier operates in its linear range at all times, resulting in minimal distortion and an incredibly rich audio experience. With a power rating of 160 watts per channel at 8 ohms and 320 watts at 4 ohms, the 1XA160.5 provides ample power to drive even the most demanding speakers.

One of the defining technologies of the Pass Labs 1XA160.5 is its use of a high-current, high-performance output stage. This design allows the amplifier to maintain dynamic control even at high volumes, ensuring that transient peaks are handled effortlessly. Coupled with a robust power supply which features a large transformer and substantial capacitance, the 1XA160.5 guarantees high performance across a wide dynamic range.

Furthermore, the 1XA160.5 is built with an emphasis on thermal management, utilizing efficient heat sinks that allow the amplifier to maintain optimal operating temperatures during extended listening sessions. Its solid aluminum chassis not only adds to its aesthetic appeal but also enhances structural integrity, minimizing microphonics and unwanted vibrations.

The 1XA160.5 amplifier is equipped with a set of balanced XLR and unbalanced RCA inputs, ensuring compatibility with various source components. It also features proprietary circuitry that enhances feedback stability and optimizes distortion performance, contributing to a cleaner, more accurate sound reproduction.

In summary, the Pass Labs 1XA160.5 power amplifier stands as a testament to the brand's dedication to authentic audio playback. With its Class A design, high-current output stage, exceptional build quality, and superior thermal management, it offers audiophiles a compelling option for achieving an unparalleled listening experience. The 1XA160.5 is not just an amplifier; it is a bridge to the emotional core of your music.