- Written by Ross Jones
- Published on 31 March 2011
The term "separates" was once reserved for the upper crust of the home theater world. Only those with the most discerning ears (and fattest wallets) considered purchasing a separate preamp/processor and multi-channel power amplifier. That time has long gone, thanks in part to the rise of Internet-direct firms such as Emotiva.
Emotiva makes amplifiers--big powerful amplifiers--and sells them direct to customers at seriously low prices. Emotiva amps have such a high price/value that a SECRETS editor who is normally not prone to dramatic statement said that his Emotiva amps would "have to be pried out of my cold, dead fingers." He was talking about the top-of-the-line XPA-1 monoblock amplifier.
Emotiva's XPA line also includes a two-channel and five-channel amplifier, and the subject of this review, the $699 XPA-3--as in three channels. I understand why someone would want a five channel amp for home theater, and a two-channel amp for stereo, but what is the purpose of a three-channel amplifier? Let's find out.
- Design: Modular, Differential (Balanced), Power Amplifier, Class AB
- Power: 200 Watts RMS into 8 Ohms, 300 Watts RMS into 4 Ohms
- THD+N: 0.1% All Channels Driven
- MFR: 20 Hz to 20 kHz, - 0.05 dB
- Input Impedance: 47 kOhms Unbalanced, 33 kOhms Balanced
- Dimensions: 7.75" H x 17" W x 19" D
- Weight: 57 Pounds
- MSRP: $699
Design and Setup
The XPA series are fully discrete, dual differential, high current, short signal path Class A/B design amplifiers. The XPA's modular design share the same glass epoxy pc boards, 1% resistors and metal film capacitors, and all XPA series amps use large toroidal transformers. The primary differences between the XPA two, three and five channel amplifiers are transformer size, secondary capacitance and number of output devices per channel. The XPA-3 has an 850VA transformer with 60,000uF of secondary capacitance, and six output devices per channel. Translated into plain English, that's a whole lotta power.
Many typical home theater receivers rate their power at something like 100 watts, but on closer inspection the specs show 100 watts when driving less than all channels (typically one or two channels), and usually a short burst rather than continuous power. Emotiva goes to the opposite extreme; the XPA manual states that "all Emotiva amplifiers are rated for continuous power, tested with all channels driven simultaneously." The XPA-3 is rated at 200 watts RMS @ 8 ohms, and 300 watts RMS @ 4 ohms (0.1% THD), with all channels driven. Emotiva publishes detailed graphs on its website, showing amplifier bench tests using an Audio Precision test analyzer (the same brand used by SECRETS Editor-in-Chief, it costs about $40,000).
The main purpose of the XPA-3 is to take over a receiver's amplifier for the front three (L/C/R) channels. Since most content (film soundtrack or multi-channel music) comes from the front of the soundstage, this is where the greatest demands will be made on a receiver's amplifier section. The XPA-3 is connected to the pre-amp outs on the receiver for the front channels, allowing the receiver's entire amp section to power the less used surround channels. Theoretically, substituting the XPA-3 for a low-powered receiver's amp section will result in dramatic sound improvement, while adding the XPA-3 to a more robustly powered receiver will make for more modest gains. However, as described below, I found that even when pairing the XPA-3 with a beefy-powered THX Ultra2 certified receiver, the Emotiva can make a big difference when driving low sensitivity or 4 ohm speakers.
The XPA-3 is bigger and heavier than most home theater receivers. It weighs 57 pounds, and at 17 x 7.75 x 19 inches (W/H/D) is a tight fit in a standard 19" rack. The front of the unit has a single glowing power button, along with three LED channel status lights. In standby mode (there is a master power switch on the back of the amp), the power button glows orange. When powered up using either the front button or via 12V remote trigger input, the status lights flash red, then sequentially turn to blue as the internal circuits confirm that the amp is operating normally. The channel status LED's can be turned off via a switch on the back panel, but the power light is not dimmable. Since the amp sat behind a perforated metal door of my rack, the blue power status LED was never a distraction.
The back panel of the XPA-3 will be familiar to anyone with an XPA series amplifier. The right side has the master power switch and a detachable IEC mains connector that runs on 115V or 230V automatically, without user adjustments. There are separate inputs for each channel, both single-ended RCA and balanced XLR. Each channel has a switch depending on whether balanced or unbalanced inputs are being used. Below the inputs are five-way binding posts for speaker terminals. The left side of the back panel has a jack for remote trigger, and the XPA-3 packaging included the necessary mini-jack cable. I used the 12V trigger on my Integra DTR 8.9 receiver, which worked flawlessly powering the Emotiva whenever I turned the receiver on or off.
I connected the pre-outs of the Integra's left, right and center-channels to the unbalanced inputs of the XPA-3 using single-ended cables (the Integra does not have XLR pre-out jacks), leaving the Integra to power the left and right surround speakers. During my review period, I used three different sets of speakers: MK Sound 950 Series speakers, Crystal Acoustics TX-T3SE THX Ultra2 certified speakers, and my usual B&W CDM NT series speakers.
Matching the XPA-3 with the Integra DTR-8.9 was probably a little unfair to the Emotiva, as I'm guessing that the typical buyer of an XPA-3 is not using it to supplement a $2,000 THX Ultra2 certified receiver rated at 140 watts. Nonetheless, adding the XPA-3 made an audible improvement to the Integra's sound, ranging from subtle to dramatic depending on the speakers.
The most striking difference was when I used the XPA-3 to power the MK Sound 950 speakers. The MK's are rated at 4 ohms, which present a more difficult load for the amplifier. Even though the Integra handled the MK's fine when driving all five channels, adding the brawn of the XPA-3 brought out a surprising amount of additional details, particularly in the mid to upper frequencies from 1 kHz-5 kHz.
I never seem to tire of The Beatles Love (DVD-A), especially the non mashed-up tracks. With the XPA-3 powering the front channels, the MK's had added depth in the flanging effects on John's lead vocal in Lucy in the Sky with Diamonds, and brought out Ringo's subtle (and underrated) hi-hat work on the track.
The contrast in sound quality was less stark when matching the XPA-3 with the highly sensitive Crystal Acoustics TX-T3SE speakers (92 dB/2.83V/m). However, the big difference was that with the Emotiva driving the front channels, I could really crank up the volume without it sounding "loud" or compressed.
Iron Man 2 was an inevitable let-down as a movie, but the DTS-HD Master Audio soundtrack had plenty of ear candy in the form of flying armored suits, missiles and explosions galore. The sound of the Emotiva reminded me of being in a high-end commercial movie theater, where the volume is dialed up to reference level but you never feel listener fatigue because it is so clean.
The difference between the Integra and the XPA-3 was least pronounced using my B&W speakers. The classic British sound, slightly laid back with a rich mid-range, remained the same. The Emotiva did bring out a subtle but noticeable increase in imaging, and a more coherent soundstage, particularly with multi-channel music recordings.
I don't meditate, but when I want to block out the world, nothing beats turning off the lights, settling back in the recliner and hitting "play" on Pink Floyd's Dark Side of the Moon (SACD). Here, the Emotiva was an addition via subtraction. The quiet space between the instruments was apparent, letting details such as a drumstick brushing against the ride cymbal during Speak to Me/Breathe, to hang in the air.
On the Bench
The Emotiva series of multi-channel power amplifiers are modular, so the bench tests for the XPA-2 will be the same as for the XPA-3.
The Emotiva XPA-3 is a no-brainer when it comes to bang-for-the-buck upgrades to a receiver-based home theater system. The difference will depend on the power of your existing receiver's amp, and the speakers' sensitivity and impedance; your own mileage may vary. I can't say that the XPA-3 will have to be pried out of my cold, dead fingers; but let's put in this way: It's not leaving the house and will remain a permanent part of my system. You can definitely consider that as a recommendation.