Pass Labs Monoblocks

[Sourn Rose]

ThePass Labs XA60.8 Monoblock Amplifier is a true powerhouse in the world of high-end audio amplification. The XA60.8 is a reference-quality monoblock amplifier, meticulously crafted to deliver unparalleled sonic performance. With a robust Class A topology, each XA60.8 amplifier is capable of delivering a substantial 60 watts of pure power into 8 ohms, ensuring dynamic and detailed sound reproduction. The symmetrical circuitry and premium components contribute to its exceptional clarity and accuracy, allowing the listener to experience music with unmatched realism. Equipped with balanced (XLR) inputs, large heat sinks, and a sophisticated power supply, the Pass Labs XA60.8 Monoblock Amplifier represents the pinnacle of audio engineering, offering audiophiles and music enthusiasts an unparalleled listening experience.

Dragon Cable Recommendation: we recommend pairing the XA60.8 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.

Bringing forth the exceptional sonic qualities of the renowned .8 amplifier line, the Pass Labs XA60.8 Monoblock Amplifiers stand as a testament to dedicated performance. Each pair of XA60.8's presents the listener with the exquisite precision of mono-block design, where dedicated power supplies, dedicated circuitry, and dedicated chassis for each channel work in perfect harmony. This meticulous approach ensures a cleaner, more defined image and expansive soundstage, captivating both the ears and eyes. The XA60.8's achieve levels of focus and intimacy typically associated with the finest tube amplifiers, offering a rich and immersive audio experience. Despite this finesse, these monoblocks do not compromise on power and control, delivering 60 watts of pure, dynamic energy per channel. With the Pass Labs XA60.8 Monoblock Amplifiers, discerning audiophiles are treated to a harmonious blend of artistry and engineering, allowing music to be experienced in its purest form.

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.

The Pass Labs XA60.8 Monoblock Amplifier is rated at 60 Watts per channel into 8 ohms. This robust power output, combined with its Class A operation, ensures ample power delivery for a wide range of speakers. The XA60.8 is designed to drive demanding loads with ease, providing dynamic and detailed sound reproduction.

The Pass Labs XA60.8 stands out for its pure Class A operation and meticulous design. It is a true Class A amplifier, meaning it operates in Class A mode at all times, regardless of the output level. This design choice contributes to its warm, natural sound signature and exceptional musicality. The XA60.8 is also known for its low distortion and high-current delivery, ensuring an engaging and lifelike listening experience.

No, the Pass Labs XA60.8 Monoblock Amplifier is designed to operate as a single-channel (monoblock) amplifier and cannot be bridged for higher power output. Each XA60.8 unit is a standalone amplifier, providing 60 Watts of power into 8 ohms. However, users can pair multiple XA60.8 units for multi-amplification setups, allowing for bi-amping or tri-amping configurations for even greater control and performance.

The Pass Labs XA60.8 Monoblock Amplifier is 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.

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.

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.

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.

Could the Pass Labs XA30.8 stereo amplifier be one of the greatest amplifiers currently available for the most discerning audiophile? Howard Milstein dissects this profoundly exquisite, angelic power amplifier in full detail!

However, one can make a good, substantial argument that some extraordinarily designed Class A/B and believe it or not, in some situations, certain Class D amplifiers can give some specific Class A amplifiers a good run for their money (with more usable power if so desired) as to their subjective sound quality!

The XA30.8 being scrutinized here delivers 60W per channel into a 4-ohm load (30 into an 8-ohm load) in full Class A operation. At that point, it transitions into class AB operation like a normal amplifier and keeps going to over 100W per channel before it reaches 1% distortion! As such the 30W power spec is a massive (Nelson Pass) underestimate of what the amplifier is capable of. Even at that 100W per channel level, the clarity, transparency, authoritative control, and auspiciously engrossing, yet fluidly elegant transient response of the Pass 30.8 is something that simply cannot be ignored.

Undoubtedly, the Pass Labs XA30.8 is a truly balanced unit! The X.8 Series amplifiers are models of electronic elegance, delivering more power with fewer stages, lower distortion, and less feedback than ever before. The series consists of nine Class-A amplifiers, four two-channel and five Monoblock models.

Being that the XA30.8 amplifier input impedance is 50 Kohms single-ended and 100 Kohms balanced, and the input capacitance is just a few picofarads, just about anything will drive it. If you happen to be using RCA inputs, then you want to use the gold input jumper to short the (-) input (pin 3) of the XLR connector to the ground (pin 1).

If we take a look at this amplifier as to its cosmetics, it is undoubtedly beautifully constructed with the feel of the highest, most refined, sturdy, and stable of any amplifier I have recently had the pleasure of using. (quite on par with the darTZeel CT-8550mk.II but a bit heavier).

It may not necessarily take the most discriminating audiophile ears to be able to analyze just how pronounced this amplifier sounds. I initiated my listening sessions at slightly lower sound pressure levels to enable myself to absorb just what distinct quality differences this Class A power amplifier could project unto the musical program sources and my system components used in this review.

When tonal accuracy is combined with loudspeakers and program material that contain some of the most neutral fundamental qualities, the listening sessions turn out to be as close to a standard of excellence that is quite inimitable: the closest one can get in a listening room to a great seat in your most esteemed concert hall. (when you concentrate your eyes and ears at the loudspeakers and wall behind them.) The XA30.8 without any doubt brings that enviable experience as close as possible for the avid audiophile and music lover.

If we take a look at some distinctly praised high-end audiophile amplifiers that listeners may find as useful comparisons, the immediate products that may encompass similar sound qualities (although in these cases at much higher price points) that come to mind are:

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