Introduction

X600.5 Owners Manual

The Pass Laboratories ™ X600.5 stereo amplifier embodies the de- sign technology and refinements of the “X” series amplifiers includ- ing extensions of the patented Supersymmetry™ circuit. Additionally selected refinements of the XA series amplifiers have been incorpo- rated into the X600.5 to significantly improve this products sonic performance in comparison to it’s immediate predecessor, the Pass Laboratories™ X600.

The Supersymmetry™ circuit topology was granted a U.S. patent in 1994, and was the result of 19 years of effort by legendary analog designer and company founder Nelson Pass. The amplifier uses highly matched components in a classically simple single ended Class A circuit. The amplifier contains only two simple stages: the first is a balanced Class A gain stage. Its output drives a bank of high power devices operated as followers.

These are inherently low distortion types of circuits, but their perfor- mance is significantly improved when operated as balanced devices. Distortion and noise identical to both halves of a balanced circuit can be made to disappear at the output, and in a well-matched symmetric circuit, most of the distortion and noise is identical.

Pass Laboratories Supersymmetry™ enhances this effect by provid- ing a connection between the two halves of the balanced circuit that further perfects the match of common mode artifacts. Any distor- tion and noise not already identical to the two halves is made more identical by a factor of about 10. The result of this perfected match is improved noise cancellation at the output of the amplifier. From a listeners standpoint this results in a more accurate presentation of the soundstage and better resolution of low level detail.

Unlike feedback techniques where the goal is to correct for the distor- tion by feeding a gain stage an inversely distorted signal, Supersymme- try™ seeks merely to create perfect matching between the two halves of an otherwise well matched circuit.

Matched balanced power circuitry typically sees a distortion and noise reduction of about 90% (20 dB) through a balanced connection without any additional effort. The Supersymmetry™ circuit delivers another 90% reduction, so that the X series has about 1/100 of the distortion of a conventionally simple and otherwise identical ampli- fier. Distortion and noise can still be seen at the output of one half of the circuit, but since it is virtually identical on the other half, these un- desirable artifacts largely go away at the speaker terminals. This gives good measured performance, and because a simple circuit produces it, also sounds quiet excellent.

X600.5 specifications

The Pass Labs X600.5 is a high-performance power amplifier that has garnered acclaim in the audiophile community for its meticulous engineering and sonic fidelity. Built on decades of research and innovation, this amplifier exemplifies the brand's commitment to creating equipment that enhances the listening experience while maintaining musical integrity.

A standout feature of the X600.5 is its impressive output power of 600 watts per channel into 8 ohms, and an even more formidable 1200 watts into 4 ohms. This level of power ensures compatibility with a wide range of loudspeakers, making it a versatile choice for audiophiles seeking dynamic range and authority in their music playback. With its Class A/B topology, the X600.5 is designed to operate efficiently while delivering the sublime warmth and detail characteristic of Class A amplifiers.

One of the key technologies that sets the X600.5 apart is its fully differential design. This architecture significantly reduces noise and distortion, providing a cleaner and more lifelike sound. This design involves a balanced input stage, which ensures that any extraneous interference is canceled out, allowing only the true musical signal to pass through. This attention to detail results in a deep soundstage and remarkable imaging capabilities, creating an immersive listening experience.

The X600.5 is also equipped with a robust power supply featuring a massive transformer and extensive power storage. This ensures that the amplifier can deliver peaks without strain, providing the transient response necessary for high-resolution recordings and dynamic musical passages. Additionally, the large heat sinks help to keep the amplifier cool during operation, which enhances reliability and longevity.

Cosmetically, the Pass Labs X600.5 exudes elegance with its minimalist design, sleek aluminum chassis, and user-friendly front panel controls. The build quality is exceptional, featuring a solid and durable construction that not only looks good but also contributes to the performance by minimizing resonance and interference.

In summary, the Pass Labs X600.5 is a powerhouse of an amplifier that combines robust performance, innovative technology, and stunning sound quality. It is an ideal choice for serious audiophiles and music enthusiasts seeking to elevate their listening experience to new heights. With its combination of power, precision, and elegance, the X600.5 stands out as a premier offering in the high-end audio market.