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The Pass Labs XA30.5 at $5,500 for a 30-Watt power amp is the living, breathing definition of audio jewelry. Designed by legendary engineer, Nelson Pass (Adcom, Threshold, First Watt, Pass Labs), this amp is designed for those with a taste for the best. It's the smallest but most tasty white truffle in the case for those who know what pure, clean sound is and are willing to pay for it. Note: the Pass Labs XA30.5 isn't for everyone. It's really a solid state alternative to the single-ended triode tube amp but doesn't come with the tubes, heat and miniscule power output. With that said, you are paying 300 plus Watt per channel money for 30 Watts per channel of audio-goodness. How can this make sense?

Lower power Class-A amps are a cult audiophile component that requires you to use speakers that are willing to play along. Forget Revels and many Bowers & Wilkins. You really need higher efficiency loudspeakers to get the most out of a Class-A amp packing only 30 Watts - at least if you plan on any spirited listening. You don't drive electrostats or harder-to-drive speakers like a THIEL with a 30-Watt Class-A amp. Wilson Audio, Focal, some Bowers & Wilkins and a whole host of other options from brands like Tekton Audio, Avantgarde and beyond will fit the bill nicely though. 

When I worked for Mark Levinson at Cello Music and Film Los Angeles, we sold very high-end Tom Colangelo designed Class-A amps that sounded just like tubes but without the tube headaches and service. Mark explained Class-A operation as the most wasteful design for an amp in terms of power in versus power out but the resulting power out was the sweetest of nectar. He went on to compare a Class-A power amp to a faucet that could only run all the way on. Class-AB amps (think Pass Labs X250, Krell 402e, Mark Levinson 532h, Classe CT-M600s are able to draw from the wall differently. Most music doesn't need all of the power an amp can provide all the time but when the musical soundtrack (or movie for that matter) swells up, the power needs go through the roof and a Class-AB amp draws from the wall as needed. Class-A amps run balls-out all the time. They provide the power they can offer more evenly and with a controlled, stable sound that Class-AB amps can't compete with. 

The Hookup
Setting up this 75 pound amp is not really much different than setting up any power amp that you might encounter. Unbox. Drool at the gorgeous metal work and blue meter that makes McIntosh look cheap. Quickly, plug in XLR cables (many would use RCAs depending on the setup) and let the sucker break-in. Now break-in is a worthy topic for a Class-A amp. If you are going to bring one home for an audition, then you should make certain that the amp has had no less than 100 hours of time on it. I could make the argument that the amp doesn't really come to life until about 250 hours of break-in. If you think that is silly, then you are either a) normal or b) a Class-AB client. Class-A amps need major break-in time to come to life. They also sound best when left on, which your power bill might not like but your ears will love.

In my system, I used a system sourced with an Oppo Digital BDP-93 Blu-ray/DVD-Audio/SACD player and an Apple Mac Pro tower going into a Benchmark DAC1 PRE. The Benchmark is run balanced out (XLR) via Transparent Reference interconnects and run into the Pass Labs XA30.5. The 30.5 was originally connected to Bowers & Wilkins' PM1 bookshelf loudspeaker, but were later swapped out for Focal's Utopia Diablo speakers. Regardless of the loudspeaker choice they were connected via 12-foot runs of Transparent Reference speaker cables. Simply put, the system is a small but very high-end audiophile rig designed to shine at low levels in a less-than-perfect installation in a 25 by 12 foot office. 

Performance
Sonically, there is nothing quite like a Class-A amp. While the sound has that "pure" feeling, it isn't as rich, lush and soft as some tubes. The Pass Labs XA30.5 is more of an analytical amp but that can easily be misconstrued to be edgy, harsh or tiny sounding. The Pass Labs XA30.5 is none of those. It's deep, accurate and controlled in ways that you might not believe. Its ability to power speakers is greater than what you might think a 30-Watt amp can do but it must be enjoyed in the right context.