Pass Labs
INT-250 Stereo Amplifier
$12,600.00 USDFeatures
250 Watts per Channel: Provides a robust 250 watts of power per channel into 8 ohms, suitable for driving even the most demanding speakers.
Symmetrical Circuitry: Ensures balanced and accurate audio reproduction, capturing the subtlest musical details.
High-Quality Components: Meticulously selected components contribute to the amplifier's exceptional sound clarity and dynamics.
Built-in Preamplifier: Features a built-in preamplifier section for added convenience and versatility.
Balanced (XLR) and Single-Ended (RCA) Inputs: Offers both balanced and single-ended inputs for flexible connectivity options.
Dual-Mono Construction: The INT-250 is built with dual-mono construction to eliminate crosstalk and interference between channels.
Large Heat Sinks: Equipped with large heat sinks to dissipate heat efficiently, ensuring optimal performance over extended listening sessions.
Robust Power Supply: Features a robust power supply design for stable and reliable performance.
Precision Volume Control: Features precise volume control for fine adjustments to suit individual listening preferences.
Efficient Loudspeaker Compatibility: Ideal for use with a wide variety of loudspeakers, providing engaging and detailed sound reproduction.
Reliable Performance: The INT-250 amplifier is designed for reliability and long-term performance, requiring minimal adjustments.
Musicality: Known for its musicality, the INT-250 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.
Minimalist Design: Boasts a clean and minimalist design that reflects Pass Labs' commitment to simplicity and performance.
What's in the Box?
Warranty
The Pass Labs INT-250 Stereo Amplifier is a powerhouse of audio engineering that sets a new standard for sonic excellence. The INT-250 is a reference-level integrated amplifier designed to deliver 250 watts per channel into 8 ohms, showcasing Pass Labs' renowned Class A/B topology for exceptional sound quality. Its symmetrical circuitry and meticulously selected components ensure precise and transparent audio reproduction, revealing the finest nuances in your music. Equipped with a built-in preamplifier section, the INT-250 offers versatile connectivity options including balanced (XLR) and single-ended (RCA) inputs. With its dual-mono construction, robust power supply, large heat sinks, and minimalist, elegant design, the Pass Labs INT-250 is the ultimate expression of audio refinement for the most discerning audiophiles.
Dragon Cable Recommendation: we recommend pairing the X250.8 stereo amplifier with our award-winning Silver Dragon Interconnects. 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 Blue Dragon Power Cable is also recommended to provide the cleanest and unbridled power to your high-end amplifier.
Features:
- Class A/B Topology: Utilizes Pass Labs' renowned Class A/B topology for outstanding sound quality and low distortion.
- 250 Watts per Channel: Provides a robust 250 watts of power per channel into 8 ohms, suitable for driving even the most demanding speakers.
- Symmetrical Circuitry: Ensures balanced and accurate audio reproduction, capturing the subtlest musical details.
- High-Quality Components: Meticulously selected components contribute to the amplifier's exceptional sound clarity and dynamics.
- Built-in Preamplifier: Features a built-in preamplifier section for added convenience and versatility.
- Balanced (XLR) and Single-Ended (RCA) Inputs: Offers both balanced and single-ended inputs for flexible connectivity options.
- Dual-Mono Construction: The INT-250 is built with dual-mono construction to eliminate crosstalk and interference between channels.
- Large Heat Sinks: Equipped with large heat sinks to dissipate heat efficiently, ensuring optimal performance over extended listening sessions.
- Robust Power Supply: Features a robust power supply design for stable and reliable performance.
- Precision Volume Control: Features precise volume control for fine adjustments to suit individual listening preferences.
- Efficient Loudspeaker Compatibility: Ideal for use with a wide variety of loudspeakers, providing engaging and detailed sound reproduction.
- Reliable Performance: The INT-250 amplifier is designed for reliability and long-term performance, requiring minimal adjustments.
- Musicality: Known for its musicality, the INT-250 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.
- Minimalist Design: Boasts a clean and minimalist design that reflects Pass Labs' commitment to simplicity and performance.
The Pass Labs INT-250 integrated amplifier stands as a testament to Pass Lab's unwavering commitment to pushing the boundaries of audio excellence. Building upon the groundbreaking design principles established in the .8 series power amplifiers and shared with its sibling, the INT-60, the INT-250 elevates the concept of integrated amplification to new heights.
At the core of the INT-250's impressive performance is its prodigious power output. Delivering a staggering 250 watts per channel, this amplifier possesses the muscle to effortlessly drive even the most demanding loudspeakers. This remarkable feat is achieved through the implementation of higher-power MOSFETs in greater numbers than its predecessors. The result is an amplifier that not only produces substantial power but does so with grace and finesse. The INT-250's ability to control loudspeakers is nothing short of extraordinary. Large, inefficient speakers that might cause lesser amplifiers to struggle are handled with aplomb. This translates to bass reproduction that is tight, controlled, and impactful, without a hint of bloat or muddiness. In the midrange, voices and instruments are rendered with stunning clarity and presence, allowing listeners to discern subtle nuances in performances that might otherwise be lost. The high frequencies sparkle with air and extension, never veering into harshness or stridency.
One of the most impressive aspects of the INT-250 is its ability to maintain composure across all volume levels. At lower volumes, it preserves the delicacy and micro-dynamics of the music, ensuring that even subtle passages are reproduced with accuracy and emotion. As the volume increases, the amplifier scales effortlessly, filling larger rooms with sound that remains coherent, detailed, and free from distortion. This versatility makes the INT-250 equally at home in intimate listening sessions or when tasked with energizing a party. The preamplifier section of the INT-250 is no less impressive than its power amplification stage. Utilizing advanced circuit design and premium components, it provides a pristine signal path that preserves the integrity of the source material. Multiple inputs, including balanced XLR and single-ended RCA connections, offer flexibility for integrating a wide array of high-end sources. The volume control, a critical component in any preamplifier, is implemented with precision, allowing for fine adjustments without any loss of channel balance or degradation of the signal.
Physically, the INT-250 is a masterpiece of industrial design. Its substantial chassis, adorned with elegant heat sinks, not only serves a functional purpose but also conveys a sense of purpose and permanence. The front panel, with its minimalist aesthetic and precision-machined controls, offers a tactile experience that matches the amplifier's sonic performance. Despite its power output, the INT-250 runs surprisingly cool, thanks to its efficient design and generous heat dissipation capabilities. Perhaps the most remarkable aspect of the INT-250 is its ability to breathe new life into familiar recordings. Listeners often report rediscovering their music collections, hearing details and nuances that were previously obscured. This is not merely a matter of revealing more information; rather, it's about presenting the music in a more coherent, emotionally engaging manner. The INT-250 has an uncanny ability to strip away the artifice of reproduction, leaving the listener with a direct connection to the artist's intent.
For audiophiles seeking the ultimate in integrated amplification, the Pass Labs INT-250 represents a pinnacle achievement. It combines the convenience of a single-chassis solution with performance that rivals, and in many cases surpasses, separate high-end components. Whether paired with esoteric, power-hungry loudspeakers or more modest setups, the INT-250 has the capability to elevate the entire system, creating a synergy that results in truly transcendent musical experiences. In a world where hyperbole is often overused, the INT-250 stands as a genuine game-changer. It challenges preconceptions about the limitations of integrated amplifiers and sets a new standard for what is possible in high-end audio reproduction. For those who demand the very best and refuse to compromise, the Pass Labs INT-250 offers a path to audio nirvana, promising countless hours of musical bliss and emotional connection to cherished recordings.
As you move up the INT lineup from the INT-25, to the INT-60, to the INT-250 you'll hear more gravitas to the sound. Larger soundstage, better dynamics, and a more impactful musical presentation. The INT-60 has more slam, faster sonic deliveries, and a greater sense of dynamic scale than the INT-25, and even more so as you move up to the INT-250.
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.
What's in the Box?
- INT-250 Stereo Amplifier
- Power Cable
- Manual and Warranty
F.A.Q.
What is the power output of the Pass Labs INT-250 Stereo Amplifier?
The Pass Labs INT-250 Stereo Amplifier delivers 250 Watts per channel into 8 ohms. This substantial power output ensures dynamic and authoritative performance with a wide range of speakers, even those with demanding impedance curves or low sensitivity. The INT-250 is designed to drive speakers with precision and control, delivering exceptional sound quality across the frequency spectrum.
What distinguishes the Pass Labs INT-250 from other stereo amplifiers?
The Pass Labs INT-250 is renowned for its combination of power, precision, and musicality. It features a high-current, Class A/B output stage for robust and dynamic performance, along with a fully balanced input stage for exceptional signal integrity. The INT-250 also incorporates Pass Labs' advanced power supply design and meticulous circuitry layout, resulting in low distortion and outstanding sonic purity. Its versatile design and high power output make it suitable for a wide range of audio systems and speaker setups.
Can the Pass Labs INT-250 handle difficult speaker loads?
Yes, the Pass Labs INT-250 Stereo Amplifier is designed to drive a variety of speakers, including those with challenging impedance characteristics or low sensitivity. Its high-power output, combined with its stable and high-current design, enables it to handle demanding speaker loads with ease. Whether driving efficient bookshelf speakers or large floor-standing models, the INT-250 delivers authoritative and controlled sound reproduction across the entire volume range.
Does the Pass Labs INT-250 require any special considerations for setup or maintenance?
The Pass Labs INT-250 Stereo Amplifier is designed for ease of setup and reliable operation. It does not typically require bias adjustments, as it is a self-biasing Class A/B design. However, users should ensure proper ventilation to dissipate heat generated during operation, as the INT-250 can produce significant thermal energy at higher power levels. Adequate airflow around the amplifier will help maintain optimal performance and prolong its lifespan. Additionally, users should follow Pass Labs' recommendations for safe and appropriate 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 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 cascoded 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.
Specifications
| Class | AB |
|---|---|
| Type | Stereo |
| Gain (dB) | 30/36 |
| Volume control (1dB steps) | 63dB |
| Remote | yes |
| Inputs | 4 |
| Outputs | 2 |
| Power Output /ch (8 ohm) | 250 Watt |
| Power Consumption (W) | 450 |
| Standby Power Consumption (W) | <1 |
| Dimensions (W x D x H) | 19 x 21.25 x 9.1 |
| Weight (LBS) | 105 |