XA25 Stereo Power Amplifier

The Pass Labs XA25 power amplifier is a marvel of audio engineering that sets a new standard in performance and clarity. The XA25 is a compact yet formidable amplifier, meticulously crafted to deliver breathtaking sound quality. Featuring Pass Labs' renowned Class A topology, this amplifier produces 25 watts per channel into 8 ohms (or 50W rms @ 4 ohms), with the ability to drive even the most demanding speakers effortlessly. Its symmetrical circuitry and high-quality components ensure pure, distortion-free audio reproduction. With its minimalist design and exceptional build quality, the Pass Labs XA25 is a true audiophile's dream, offering an unparalleled listening experience. Dragon Cable Recommendation: we recommend pairing the XA25 Power Amplifier with the Silver Dragon Interconnect. The Silver Dragon Interconnect is one of our best-selling cables at Moon Audio. Sold in Pairs, it is our top-of-the-line silver conductor-based interconnect. With a braided geometry and amazing shielding, this interconnect is a remarkable solution where noise isolation is key. The Black Dragon Power Cable is also recommended to provide the cleanest and unbridled power to your high-end amplifier. The Pass Labs XA25 power amplifier stands as a testament to the company's unwavering commitment to excellence, offering audiophiles an entry point into the world of high-end amplification without compromising on sound quality or build integrity. Despite being the most affordable power amplifier in Pass Labs' illustrious lineup, the XA25 is far from a mere budget offering. Instead, it represents a carefully crafted balance of performance, innovation, and value that has quickly earned it a place among the most respected amplifiers in its class. At the heart of the XA25 lies its impressive output stage, designed around a single pair of 800-watt new-generation output transistors. This design choice is far from arbitrary; it allows the amplifier to operate in a push-pull Class A configuration, a topology that brings with it a host of sonic benefits. The result is an amplifier that delivers faster performance, lower distortion, reduced noise, and a higher damping factor – all crucial elements in the pursuit of audio perfection. While the XA25's rated output of 25 watts per channel might seem modest at first glance, it's important to understand that this figure tells only part of the story. The Class A operation means that the amplifier remains in its most linear, low-distortion state throughout its entire power range. This translates to a purity of sound that belies the amplifier's power rating, allowing it to drive a wide range of speakers with authority and finesse. The XA25's ability to "breathe life" into music is not mere hyperbole. Listeners often report a newfound sense of engagement with their favorite recordings, discovering nuances and emotional depths that may have gone unnoticed with lesser equipment. This amplifier has an uncanny ability to strip away the veil between the listener and the music, presenting each note and passage with clarity and immediacy that can be truly transformative. Pass Labs' X and XA line of power amplifiers have been in continuous production and refinement for over two decades, a testament to their enduring design philosophy and commitment to excellence. The XA25 benefits from this rich legacy, incorporating lessons learned and technologies developed over years of meticulous research and real-world experience. At Pass Laboratories, the focus is on building amplifiers that excel in every aspect of their design. The output stages are engineered for optimal performance, paired with high-performing and effective heat sinks to ensure thermal stability even under demanding conditions. The power supplies are a particular point of pride, designed to be exceptionally quiet while delivering clean, stable power to the amplification circuits. Component selection is another area where Pass Labs refuses to compromise. Only the highest-quality parts find their way into the XA25, each chosen not just for its electrical properties but for its contribution to the overall sonic signature. These components are arranged in simple, linear topologies – a reflection of Pass Labs' belief that the most direct signal path often yields the best results. The assembly and testing of each XA25 take place in Auburn, California, under the watchful eyes of skilled technicians who share Pass Labs' passion for audio excellence. This attention to detail ensures that every amplifier leaving the factory meets the company's exacting standards for both measured performance and subjective sound quality. While the XA25 measures impressively on the test bench – a point of pride for Pass Labs – its true magic lies in its ability to transcend mere specifications and deliver a profoundly engaging musical experience. This amplifier has a remarkable ability to combine technical excellence with emotional impact, presenting music with a sense of scale, dynamics, and realism that can be truly captivating. For those seeking a "beefy" sound without sacrificing refinement, the XA25 delivers in spades. Its robust construction and generous power supply allow it to maintain composure even when reproducing complex, dynamic musical passages. Bass notes are rendered with authority and precision, while the midrange – often considered the heart of music – is presented with a natural warmth and clarity that brings vocalists and instruments into the listening room with palpable presence. The XA25 represents a harmonious blend of proven design principles and cutting-edge innovation. By coupling new components and innovative circuits with the best elements of previous amplifier generations, Pass Labs has created an amplifier that looks both forward and back – honoring its heritage while pushing the boundaries of what's possible at its price point. In a world where the term "entry-level" often implies compromise, the Pass Labs XA25 stands as a glorious exception. It offers a level of performance that will satisfy even the most discerning audiophiles while remaining accessible to those taking their first steps into the world of high-end audio. For music lovers seeking an amplifier that combines technical excellence with musical soul, the XA25 beckons, promising countless hours of musical bliss and the rediscovery of cherished recordings, one sublime listening session at a time. Pass Labs and First Watt Pass Labs and First Watt were founded by hi-fi legend Nelson Pass. After co-founding and later selling Threshold Audio, Pass began working out of his Auburn, California, home in the early 1990s to develop prototypes of single-ended Class A amplifier designs under the name Pass Labs. Pass Labs quickly became known for its commercially produced Aleph, X, and XA Series amps, and preamps. Pass later started First Watt as a passion project focusing on low-power amps for a niche audiophile audience. Today, Pass splits his time between the two companies, with production happening in Pass Labs' facility in Foresthill, California, USA. Some of Pass Lab’s most notable products include the HPA-1 Headphone Amplifier, their integrated amp series (featuring the Pass Labs INT-25, Pass Labs INT-60, and the Pass Labs INT-250), the Pass Labs XA25, and more. If you’re looking for a monoblock amplifier, stereo amplifier, integrated amplifier, or headphone amplifier, then Pass Labs has everything you need for your high-end audio. Visit passlabs.com for more info. Features: Pure Class A Operation: The XA25 operates in Class A for pristine sound quality and low distortion. 25 Watts per Channel: Provides 25 watts of power per channel into 8 ohms, suitable for a variety of speakers. Symmetrical Circuitry: Ensures balanced and accurate audio reproduction, capturing fine musical details. High-Quality Components: Meticulously selected components contribute to the amplifier's exceptional sound clarity and dynamics. Minimalist Design: Boasts a clean and minimalist design that reflects Pass Labs' commitment to simplicity and performance. Robust Power Supply: Features a robust power supply for stable and reliable performance. Efficient Loudspeaker Compatibility: Ideal for use with sensibly efficient loudspeakers, providing engaging and detailed sound reproduction. Single-Ended (RCA) Input: Offers both balanced and single-ended inputs for flexible connectivity options. Reliable Performance: The XA25 amplifier is designed for reliability and long-term performance, requiring minimal adjustments. Musicality: Known for its musicality, the XA25 amplifier allows listeners to fully immerse themselves in the nuances of their favorite music. Exceptional Transparency: Delivers exceptional transparency and clarity, allowing the listener to hear every detail in the music. Solid-State Design: Offers the benefits of solid-state amplification, including efficiency, reliability, and stable performance. Premium Build Quality: Crafted with attention to detail and high-quality materials for a durable and long-lasting amplifier. What's in the Box? XA25 Power Amplifier Power Cable Manual and Warranty FAQ What is the output power rating of the Pass Labs XA25 Power Amplifier? The Pass Labs XA25 Power Amplifier is rated at 25 Watts per channel into 8 ohms and 50 Watts per channel into 4 ohms. Despite its relatively low wattage compared to higher-powered amplifiers, the XA25 is designed to deliver exceptional sound quality with a focus on Class A operation. It is ideal for use with efficient speakers in smaller to medium-sized rooms, providing a clean and detailed listening experience. What distinguishes the Pass Labs XA25 from other amplifiers in the Pass Labs lineup? The Pass Labs XA25 is unique within the Pass Labs lineup due to its Class A operation and minimalist design. It is a pure Class A amplifier, meaning it operates in Class A mode at all times, regardless of the volume level. This design choice contributes to its warm, detailed sound signature and ability to maintain musicality even at lower volumes. The XA25 is also known for its low distortion and high-current delivery, resulting in a natural and engaging listening experience. Can the Pass Labs XA25 drive difficult speaker loads? While the Pass Labs XA25 is not designed for highly inefficient or extremely low-impedance speakers, it is capable of driving a wide range of speaker loads effectively. It pairs exceptionally well with high-efficiency speakers that benefit from its Class A operation and high-current delivery. The XA25's 25 Watts per channel into 8 ohms is ample for many high-quality speakers, offering a clean and dynamic sound reproduction. Does the Pass Labs XA25 require any special considerations for setup or maintenance? The Pass Labs XA25 Power Amplifier is designed to be relatively straightforward to set up and operate. It does not require bias adjustments, as it is a self-biasing Class A design. However, users should ensure proper ventilation for optimal performance, as Class A amplifiers can generate heat. Adequate ventilation will help maintain the amplifier's performance and longevity. Additionally, it is recommended to provide sufficient space around the amplifier for airflow and to follow Pass Labs' guidelines for safe and optimal operation. Who is Nelson Pass? Nelson Pass, the man behind Pass Labs and First Watt, has been designing and building amplifiers for decades. His early passion, however, was speakers; at age 14, he started assembling loudspeakers. As a college student studying physics at the University of California-Davis, he co-founded a speaker company called PMA. He also worked for ESS, where he designed crossovers and enclosures. After college, with his interest having shifted toward amplifiers, Pass co-founded Threshold Electronics (now Threshold Audio). His achievements during the Threshold years include developing the first dynamically biased Class A amplifier circuit; developing a fully cascode audio power amplifier; and developing the STASIS stereo preamplifier and power amplifier. During the 1980s, Pass designed the Adcom GFA-555 amplifier. Later, after selling Threshold, he started Pass Labs in 1991 and First Watt in 1997. Pass holds several patents related to audio circuits. How did Pass Labs make its name? Pass Labs helped popularize solid-state, Class A power amplifiers. Pass Labs' first product, the Aleph 0 amplifier, operated as a single-ended Class A up to its 70-watt rating and in push-pull Class A at higher wattage. The Aleph series of amplifiers, some of the first solid-state amps that were said to be "tube-like" in sound, operated pure class A and contained internal circuitry using MOSFETs. The Aleph amplifiers had a unique appearance, a cube with heat sinks on all four sides, a solution to the heat generated by the class-A design. This can be attributed primarily to the specific MOSFETs used and the minimum number of gain stages that were implemented in the design. Pass Labs also developed the Super-Symmetry™ ("Su-Sy") circuit, which achieves exceptionally low distortion and noise levels. In 1998, Pass Labs released the X1000, the first amplifier using the patented SuperSymmetric™ topology. The X1000 achieved 1000 watts with high performance, local feedback, and only two gain stages: a cascaded differential pair of transistors and a large bank of complementary output followers. This groundbreaking design informed all subsequent Pass Labs amplifiers. What else does Pass Labs make? In 2002, Pass Labs unveiled the first XA amplifiers, combining the X and Aleph topologies into balanced single-ended Class A amplifiers with many of the characteristics of both the X and Aleph series. The current Pass Labs lineup includes Class A amps (XA and Xs Series), Class AB amps (.8 Series), line preamps (Xs and XP Series), phono preamps (Xs and XP Series), integrated amps (INT Series), and one headphone amp. What is the relationship between Pass Labs and First Watt? When he started Pass Labs, Pass did everything out of his home. In 1997, having outgrown the space, Pass Labs moved into commercial space in Foresthill, California. When Pass started First Watt, it was a "kitchen table" venture, with work once again happening in his home. In 2016, with production demands not leaving him enough time to pursue the vast array of yet-to-be-designed amps, Nelson handed the business end of First Watt over to Pass Labs. Pass Labs took over the building of First Watt amplifiers as well as marketing and distribution. There's a synergy between the two operations, in that Pass Labs gets to gather up some of the more interesting First Watt finds and repurpose them as more commercially viable designs. Today, Pass splits his time between First Watt and Pass Laboratories.