Emotiva Audio XPA-1L Class A and AB Mono Amplifier Preview

Anyone who's been around the audio game for any length of time knows one "truth"—sound has only been getting worse. Just ask any audiophile. Vinyl is the best. Digital amplifiers sound "mechanical". Aluminum cones sound "metallic". The "theories" are never ending. While we don't subscribe to many (most) of these ideas, one thing is certainly true: Class A amplifiers weren't supplanted because people thought other amplifier typologies sounded "better". No, the reason was because Class A amplifiers were horribly inefficient (losing up to 80% of their power to heat—sometimes more). On top of that, while sitting and not doing anything, Class A amps continually power the transistors, meaning they are always drawing significant power from the wall. This makes them not only hot but also expensive to run.

But the upside is that Class A amplifiers are some of the most accurate amps out there. The inefficient design, however, has seen them fall out of favor. But for audiophiles, there is nothing that they won't do for sonic purity. This has seen Class A amplifiers becoming the things of legend and coveted by audiophiles the world over. The popular (and used in most receivers these days) compromise is the Class A/B amplifier. Class A/B combines a Class A amp and a Class B. A Class B amp has no power flowing through the transistors at standby while the Class A has full power. With a Class A/B amp, there is a small amount of power that is flowing at standby. This gives a much higher efficiency (around 50%) but, for the audiophile, saving power at the potential expense of sonic accuracy is an unacceptable compromise.

Emotiva Audio has heard these audiophiles and has released a new monoblock amplifier, the XPA-1L. The XPA-1L is a dual-mode amplifier that can be selected for Class A or Class A/B operation based on your preferences. To start with, in Class A/B mode, the XPA-1L will output 250 watts into 8 ohms and 500 watts into 4 ohms. Emotiva recommends pairing the XPA-1L with 4 ohm rated or higher impedance speakers but it can function just fine with speakers dipping lower in impedance too.

The back of the XPA-1L has exactly what you'd expect from a high quality amplifier from Emotiva. There is a gold-plated RCA unbalanced input and a XLR balanced input. The speaker terminals are, unfortunately, located quite far away from each other (a pet peeve which may be troublesome for some users with custom cables) but feature gold-plated 5-way binding posts. The amp will accept 115 VAC or 230 VAC which is automatically detected and switched. For ease of use, Emotiva has included 12 volt trigger input and output. 

Inside we see the very interesting layout of the XPA-1L. Emotiva has included 90,000 uF of capacitance and a 450 VA heavy duty toroidal transformer. The amplifier is fully balanced, fully discrete, and features a high current, short signal path, Quad Differential design. The large internal heat sinks are to protect from overheating during Class A operation.

You can set the Emotiva XPA-1L to Class A/B or Class A operation via a switch on the front panel. When in Class A mode, the XPA-1L delivers 35 high bias watts into 8 ohms. Emotiva hasn't provided a 4 ohm rating, but we are quite confident it doesn't exactly double down in power driving a 4 ohm load when operating in this mode else it would consume way too much power. If you exceed the 35 watt threshold, the XPA-1L transitions into Class A/B, allowing it to deliver its full rated power. There is no indication from Emotiva that the XPA-1L lets you know when this happens but this will occur at much louder than background listening levels where purists will probably find acceptable. Green audiophiles wanting to save the planet and cut down on their electric bill will probably opt to run the XPA-1L in Class A/B mode all of the time.

The XPA-1L is protected against excessive operating temperatures (a necessity with a Class A design), shorted speaker connections, ground faults, and other common fault conditions. For the amount of power that it outputs, it is quite small at 17” wide by 3.875” high and 19” deep, but it still weighs in at a respectable 35 pounds. At $700, the XPA-1L isn't cheap, and a quick search of comparable Class A offerings shows it is, by far, one of the least expensive offerings. But, then again, this is Emotiva. They've made a business of undercutting the prices of everyone else. Why should the XPA-1L be any different?

Conclusion

If you've wanted to experiment with a Class A amplifier but didn't have the thousands it normally takes to step up to that level, the Emotiva XPA-1L is for you. With selectable Class A/Class A/B operation, it has something for everyone. Putting out 35 watts in Class A mode and 500 watts (4 ohms) in Class A/B mode, it should pair well with nearly any speaker you may own. We are also wondering if Emotiva is planning on implementing this Class A switch to their entire line of Class A/B amps. It would certainly help differentiate their offerings from all the other Class A/B amps out there. We are definitely looking forward to getting the Emotiva XPA-1L on our test bench.

For more information, please visit www.emotiva.com.

Unless otherwise indicated, this is a preview article for the featured product. A formal review may or may not follow in the future.