Acurus A2002 Stereo Power Amplifier

In the interest of full disclosure, I have a soft spot for Acurus amplifiers. When I first set up my home theater in 1996, I paired a Meridian 541 analog surround sound processor with a Forte FT-1 five channel amplifier. Unfortunately, the transformer in the FT-1 hummed so badly you could hear it across the room. Two trips back to Threshold’s repair facility did not solve the problem. It turned out that I had DC on the power line which caused the transformer laminations to vibrate. So I replaced the FT-1 with an Acurus A250 two-channel amplifier and an Acurus 3×100 three-channel amplifier. Much to my relief, neither hummed. Perhaps the Acurus amplifiers used higher quality transformers and/or the transformer mounts absorbed the vibrations. Or perhaps, like Bryston, they designed a DC blocking circuit as part of the power supply. Whatever the reason, both amplifiers worked quietly and faultlessly during the time I had them. The only problem I recall was that the LED built into the power switch of the A250 flickered. Mondial Designs, maker of both Acurus and its higher priced Aragon siblings, promptly sent me a replacement switch. Although I ultimately moved on to an all Meridian system with digital active loudspeakers, it is not at all unlikely that I would still have the Acurus amplifiers in my system today if I had stayed with passive loudspeakers, though I probably would have swapped the Acurus 3×100 for an Acurus A125 five-channel amplifier when I moved from a 5.1 to a 7.1 setup.

For some reason, Klipsch bought Mondial Designs in 2001. I suppose they planned to broaden their line-up to include home theater products in addition to loudspeakers. If they did, their plans never came to fruition, and the Acurus and Aragon brands disappeared from the retail scene for a decade. In 2009, Rick Santiago, Klipsch’s Vice President of Engineering, and Ted Moore, Klipsch’s Director of Electronic Systems, bought the rights to Acurus and Aragon and established Indy Audio Labs to resume manufacturing and marketing the brands. They currently offer the Acurus A2002 two-channel ($2499), A2005 five channel ($3499), and A2007 ($3999) seven-channel amplifiers. Each amplifier outputs 200 watts/channel into 8 ohms and 300 watts/channel into 4 ohms. Indy Audio Labs has quickly established a network of dealers in the U.S. and in a dozen countries around the globe. A surround sound processor - successor to the then trend-setting Mondial Designs ACT-3 - is in the works. In addition, they are poised to re-introduce Aragon amplifiers later this summer.

The Acurus A250 I owned was replaced with the A200 shortly after I purchased it. The new Acurus A2002 is its successor. Given my prior positive experience, I was excited to see the rebirth of the brand, and anxious to audition the A2002. Rick Santiago accommodated me with a review sample for several months so I could put it through its paces with several speakers, including the DALI Ikon MK6, the Focal 807W Prestige, and the B&W 683s. Although I spent the most time with the B&W 683s, the neutral character of the A2002 allowed each speaker to showcase its distinctive voice, free from coloration.

The Acurus A2002 is similar, though not identical, in appearance to the A200. It is spartan, with a black front panel, understated logo, and lighted power switch. The power switch glows red when the unit is plugged in and in standby, and turns a warp drive nacelle blue when powered on. If I remember correctly, the ventilation holes in the top of the chassis have the same design pattern as the original amplifiers. Extruded aluminum heatsinks adorn the side panels. They never got even warm to the touch. On the back panel are the unbalanced RCA inputs, two pairs of speaker binding posts, 5 to 24 volt DC trigger, IEC power inlet and integral fuse holder, and, unusual for an amplifier, RS232 and ethernet ports. The RCA inputs and speaker binding posts are gold plated. The amplifier is supported on the bottom by four heavy-duty removable thermoplastic rubber feet to isolate it from external vibrations. A rack mounting kit is available to support its 30 pound weight.

The presence of the RS232 and ethernet ports were intriguing. Essentially, Indy Audio Labs has endowed its amplifiers with a computer interface to monitor, control, and diagnose certain aspects of its operation. I have a relatively new IBM ThinkPad without a serial port, so I connected to the A2002 via ethernet. I used a crossover cable between my computer and the amplifier, but you would usually connect the amplifier to your router and access it wirelessly. All you need to do is open up your browser of choice and type in the IP address of the amplifier (192.168.1.250 in the case of the A2002) and you will be presented with an interface similar to the one shown below.

As you can see, you can turn the amplifier on and off, mute one or more channels, monitor the status and temperature of each channel, set the brightness of the power switch LED, enable or disable the web and serial port interfaces, set a dynamic or static IP address, and disable UDP commands for network security. Not something you will use everyday, but nice to have - especially the ability dial down the brightness of front panel indicator lamp.

The first thing you’ll want to do with a 200 watt amplifier is to put on some challenging music, turn it way up, and see how it acquits itself. Before doing so, I noted that the A2002 was completely silent. I placed my ear next to the top cover and heard absolutely no mechanical hum. I placed my ear next to the tweeter and, with no input connected, heard no hiss. I connected the Benchmark DAC1 HDR preamplifier I was using at the time (review upcoming), and, with no source selected and the volume turned all the way up, heard only the slightest hiss, which was not detectable from more than a few inches away.

With those preliminaries out of the way, I cued up Gaia, the fourth cut on James Taylor’s Hourglass album. It starts off ethereally with sustained notes from the keyboard, the tinkling of wind chimes, and the plucking of steel guitar strings. Then Edgar Meyer joins in on the acoustic bass providing an underlying foundation, with a restrained drum set providing the beat. James Taylor’s rich voice begins the lyrics, with female vocals in the background. Riffs from Brandford Marsalis’s soprano saxophone appear throughout. At about 4:00, another verse begins quietly, and at 4:11 out of nowhere come thunderous whacks of tympani moving across the soundstage from right to left and back to the right. It is nothing short of an amazing soundscape, requiring huge power reserves, all of which was handled with aplomb, clarity, and control by the A2002. Where the risk of an homogenized whole was high, instead each instrument occupied its own space, and an acoustic scene was painted with great precision, without being etched.

Anyone know what a harp guitar is? I was clueless until Windham Hill released phenomenal guitarist Michael Hedges’ landmark Aerial Boundaries album in 1984, and then it was only after listening to some of his other albums and doing a fair amount of research (there were no liner notes, and no internet at the time) that I was able to figure out, or so I thought, how he was able to obtain the range and speed of notes he was able to play - Michael Hedges was a virtuoso on the harp guitar. Although probably no two harp guitars are alike, their distinguishing characteristic is a plethora of additional bass and treble strings, fretted and unfretted, accessible on additional arms or necks, which give a talented guitarist, particularly one as skilled as Michael Hedges, a virtually unlimited palette. In addition, the larger soundboard gives the guitarist a broader area for percussive effects. What is almost incomprehensible is that, notwithstanding his mastery of the harp guitar, all of the instrumentals on Aerial Boundaries were performed on a standard six string guitar! If you are a guitar enthusiast and haven’t heard of Michael Hedges, pause from reading this review, and order Aerial Boundaries. When it arrives, you won’t believe what you are hearing.

Take, for example, the title cut. It starts out simply, with a beat established by “popping” the treble strings, followed by a series of hammer-ons to establish the melody. Then the foundation is laid by plucking the bass strings. The melody is further developed with hammer-ons, pull-offs, and slap harmonics. Then it is all done together, with the pace varying between slow and fast, and the density between sparse and complex, in what appears to be an improvisation, but in fact is a carefully crafted composition (he studied at the Peabody School of Music). What does this have to do with an amplifier you may ask? Well, it provides a demanding test of its ability to reproduce an amplified acoustic instrument with staggering transients and high energy high frequency response, all the while maintaining delicate harmonics and note decay. The A2002 performed admirably, all without the slightest bit of harshness or fatigue.

The Acurus A2002 can also deliver a subtle presentation. Isabella Faust is the soloist on a Harmonia Mundi collection of Bach partitas. The most familiar one on the album is Partita No. 3 in E major, BMV 1006. The performance was undoubtedly recorded with a coincident pair of microphones with additional omni-directionals strategically placed to capture the ambiance of the large hall. The violin stands front and center with each note captured with great clarity, yet there is significant reverb present. Reproducing those delicate reverb tails is not something an inexpensive amplifier can accomplish easily, due in part to its usually higher signal-to-noise ratio than its more expensive counterparts. The A2002 excels in that regard with a commendable measured value of 106db. Measurements aside, the result is that each note and its decay is distinct, without edginess. With so many notes played high on the neck, on lesser systems the sound can be piercing, and ultimately irritating. Such was not the case with the A2002. Simultaneously reproducing the mellow tones of the low strings and the crystaline high notes is no easy task. With a cooperative pair of speakers like the B&W 683s, the A2002 renders a mesmerizing soundfield.

Conclusion

Indy Audio Design has remained true to its roots. The Acurus A2002 is a worthy successor to the Mondial Design Acurus A200. With a dead silent transformer, and what seemed like unlimited power reserves, the A2002 was able to drive the 90db sensitive B&W 683s to deafening levels with no hint of distortion, yet at normal listening levels provided a nuanced presentation that made the music always engaging. Extremely well built, it will survive several rounds of upgrades of other components in your system. Move it to the top of your “must audition” list.

- Frank Berryman

Contact Information

Indy Audio Labs
5225 Exploration Drive
Indianapolis, Indiana 46241
Telephone: (866) 559-5113
www.acurusav.com/
[email protected]

Associated Equipment

Analog Source: VPI Scout; Dynavector 20X2; Musical Surroundings Phonomena II
Digital Source: Mac Mini; 16GB RAM; Halide Design Bridge and DAC HD; Pure Music playback software
Preamplifier: Meridian G68ADV; Benchmark DAC1 HDR
Power Amplifier: Meridian 557
Loudspeakers: Meridian DSP5500s; DALI Icon 6 MK2; Focal 807W; B&W 683
Cables: Digital: Meridian; USB: Wireworld Starlight; Analog: Mogami/Amphenol (RCA), Mogami/Neutrik (XLR); Speaker: Mogami/Audioquest (BFA/banana); Power: Volex/Marinco
Accessories: GIK acoustic treatments; dedicated 20 amp circuit; Audience aR2p power conditioner