– Roger Kanno, soundstagexperience.com
NuPrime Audio continues to carve out its own unique path since being spun off from NuForce (now owned by Optoma, an international manufacturer of video projectors). While Optoma NuForce continues to make lower-priced audio products, NuPrime concentrates on designing components of higher performance yet still high value, including amplifiers based on the highly respected, proprietary class-D architecture first developed by NuForce. One of NuPrime’s first products was the IDA-16 integrated amplifier-DAC ($2600 USD), reviewed for SoundStage! Access in January by Vince Hanada, who liked it so much that he bought the review sample.
Since then, NuPrime has launched a cost-effective power amplifier, a DAC-preamp, and a DAC-preamp with built-in headphone amplifier. The latest addition to their line is another integrated amplifier-DAC, the IDA-8 ($995). When I heard that NuPrime was releasing a new integrated-DAC for less than half the price of the IDA-16, I thought it would be a direct-digital design such as Optoma’s NuForce DDA120, which keeps the audio signal entirely in the digital domain until it’s sent to the speakers. Somewhat to my surprise, I discovered that the IDA-8 has much in common with the IDA-16: a class-D amplification stage mated to a conventional DAC section and a volume control. Considering how highly Vince regards the IDA-16, I was intrigued, and asked NuPrime to send me a review sample of the IDA-8.
Priming the system
The NuPrime IDA-8 isn’t simply a stripped-down IDA-16. Although it also uses NuPrime’s proprietary switching-amplifier technology, which they describe as class-D, it’s specified to output only 100Wpc into 8 ohms, vs. the IDA-16’s 200Wpc. According to NuPrime, the power-amp stage uses “a self-oscillating circuit to generate pulse width modulation,” and switches at a frequency of 600kHz — much faster than most class-D amps, which NuPrime says switch at 300kHz or less. NuPrime’s higher-end amps, such as the IDA-16, use what they call a Cross-Matrix Array (CMA) capacitor bank designed to maintain high current reserves, to be fed to the output stages as required. The IDA-8 lacks a CMA bank, instead using a simpler, linear power supply with a toroidal transformer, rather than the more complex switched-mode power supply (SMPS) found in the IDA-16.
The IDA-8 is unique among NuPrime products in having what the company describes as an Ultra Linear Class-A Module (ULCAM) preamplifier section, with discrete components claimed to reduce noise and provide maximum power. This, in combination with their propriety switching power-amp technology, results in what NuPrime calls “Class A+D hybrid” operation. The IDA-8 has a “thin-film switched-resistor ladder network for controlling volume, with a single resistor in the signal path” for each of its 99 volume settings, as well as an “FPGA (field-programmable gate array) chip to implement the switched resistor design to accomplish the same objective” as the more expensive IDA-16.
The IDA-8’s DAC is ESS’s ES9010K2M Sabre chip. Like ESS’s other Sabre DACs, the ES9010K2M has a 32-bit architecture with a maximum sample rate of 384kHz, but with only 116dB of dynamic range — less than some of their higher-end DACs, such as the ES9018K2M in the IDA-16. NuPrime sets the ES9010K2M in the IDA-8 to upsample lower-resolution digital signals to 176.4kHz, which is less than the DAC’s maximum sample rate of 384kHz. The IDA-8’s asynchronous USB input supports PCM digital signals up to 384kHz and DSD up to 11.2MHz, while its S/PDIF inputs support PCM up to 192kHz and DoP DSD up to 2.8MHz. Also included is a Bluetooth dongle that supports aptX connectivity.
The IDA-8 is compact, measuring only 9.25”W x 2”H x 11”D but weighing a surprising 9.5 pounds — it has a reassuringly solid feel. Two finishes are available: black or silver anodized aluminum. Input selection and power are controlled by a combination pushbutton and knob on the left of the front panel; an identical knob on the right controls volume and muting. The front panel is slightly convex, with beveled top and bottom edges. The easily legible blue-LED display indicates the input and volume level, though the input and volume indicators are too close together: with input C1 selected and a volume level of “40,” the result looks more like “C140.” I wished that the display could be dimmed, but it can be turned only off or on. When the IDA-8 detects the presence of a digital signal at one of its inputs, it momentarily displays the sampling rate, but there’s no way to make it display the rate again without muting and then unmuting, or changing to a datastream with a different sampling rate.
The IDA-8’s inputs and outputs are pretty standard for an entry-level integrated-DAC. There are one each of USB Type-B, coaxial, and TosLink digital inputs, and an analog stereo RCA input. A USB Type-A expansion input is provided to connect the Bluetooth dongle, along with an RCA stereo preamp output, for connection to a powered subwoofer. The speaker binding posts are of good quality and gold plated. A detachable IEC power cord is provided; next to its inlet is the main power rocker switch. The IDA-8 sits on what NuPrime describes as vibration-free isolation feet: broad, shallow cones with tips of soft, absorptive rubber.
Two remote controls are provided: a tiny one, its buttons covered by a thin membrane, that I didn’t like; and a larger one, with proper buttons covered with thicker rubber. The larger remote has an individual access button for each input, and a much better feel, so that’s what I used for my listening.
NuPrime provides only a one-year warranty for the IDA-8. I recognize that it’s a relatively inexpensive component, but Optoma NuForce offers a two-year warranty for the less-expensive DDA120, and other makers of budget gear offer warranties of two years or even longer.
I used the NuPrime IDA-8 primarily with my Asus VivoBook X200MA laptop computer running Windows 8.1 and foobar2000, connected via an AudioQuest Carbon USB cable. I also used an Oppo BDP-105 universal BD player, and speakers from Definitive Technology, GoldenEar Technology, and KEF. Interconnects and speaker cables were Nordost Quattro Fil and Super Flatline Mk.II, respectively; power cables were Essential Sound Products MusicCord-Pro ES.
For my laptop to recognize and connect with the IDA-8, all I had to do was download the driver from NuPrime’s website and install it. (NuPrime says that the IDA-8 uses a standard driver for Mac OS.) Configuring the IDA-8 to play DSD files was not quite as simple, but following the comprehensive instructions in the user manual, I was able to download the required drivers and configure foobar2000 to output DSD files without having to convert them to PCM. I also, via Bluetooth, wirelessly streamed some MP3 and WAV files from my second-generation iPod Touch, just to confirm that this feature functioned properly — no problem. While this lower-resolution wireless connection is a convenient feature, it’s not something I’d often use, especially as the IDA-8 can play hi-rez PCM and DSD files.
When I’d hooked up the Definitive Technology StudioMonitor 45 speakers to the IDA-8 and begun playing music, I realized that the NuPrime was unlike any other entry-level amplifier I’d ever had in my system. Everything immediately sounded more precise and controlled than through the Optoma NuForce DDA120 ($699), for example, which is the usual real-world amplifier that I use in this system.
The StudioMonitor 45s are moderately sized, reasonably priced bookshelf speakers with surprisingly good bass — with the IDA-8, their sound snapped into focus with a grip and articulation that I hadn’t thought possible with such a modestly priced amp. Both male and female voices sounded exceptionally clear and natural on Denez Prigent and Lisa Gerrard’s “Gortoz a Ran — J’Attends,” from the soundtrack of Black Hawk Down (16-bit/44.1kHz FLAC, Universal). The original NuForce DDA-100 ($549, discontinued) and the newer but very similar DDA120 are products that I use as affordable reference integrated amplifiers, for their detailed but smooth and powerful sound. However, the IDA-8 sounded unmistakably better than either. In fact, the little IDA-8 sounded so refined and powerful that I soon decided that, to get a true measure of its sound, I needed to move it into my reference system.
In that system I had a variety of high-end but still high-value speakers to use with the NuPrime IDA-8: the KEF R900, Definitive Technology Mythos ST-L, and GoldenEar Technology Triton Five. Even with those floorstanders, the IDA-8 was able to tightly control the low frequencies in Lorde’s bass-laden Pure Heroine (24/48 FLAC, Lava Music/Republic). The KEF R900s are nearly full range, if not quite as tight in the lowest bass as I sometimes wish they were. But when I drove the dual 8” woofers of the R900s with the IDA-8, the pounding drums and deep synthesizer tones of “400 Lux” had fast attacks and controlled decays more reminiscent of a stout power amp than a diminutive integrated — an ear-opening experience.
The IDA-8’s midrange was also something special: exceedingly clean but very full, reproducing voices with clarity and presence while also providing their full weight and body. With the IDA-8, I felt I was hearing everything in Susan Wong’s 511 (24/96 FLAC, Evosound) — not something that I think I have ever said before about an integrated amp costing under $1000. Her voice in Bruce Fisher’s “You Are So Beautiful” had a dazzling purity of tone, and it was equally pristine in “Billie Jean” — though it revealed a lack of emotion in the latter track. That it was the IDA-8 making these slight differences readily audible was made clear when I listened to my favorite track from this album, a cover of ABBA’s “The Winner Takes It All” — the IDA-8 conveyed the passion of Wong’s singing by exquisitely reproducing her more emotive vocal phrasing. The NuPrime’s sublime midrange allowed voices to float effortlessly in mid-air, where they commanded my attention — which is how I spent many hours blissfully listening to it.
The orchestral strings of the Trondheim Soloists, in Marianne Thorsen’s recordings of Mozart’s Violin Concertos Nos 4-5 (24/352.8 FLAC, 2L), were smooth without sounding dull, with a wonderful sense of envelopment of Thorsen’s violin by the orchestra, even as soloist and ensemble remained clearly distinct from each other. At very high volume levels, the IDA-8 could make the violins sound a bit hard. But at levels that to me are adequate — but that some might consider quite loud — the NuPrime remained wholly composed. The same was true of pop recordings such as Carly Rae Jepsen’s surprisingly well-produced E·mo·tion (24/44.1 FLAC, Universal), which the IDA-8 had no problem reproducing at high levels. Jepsen’s voice is quite closely miked and exhibits moderate sibilance, but the IDA-8 reproduced it with neutral, easygoing sound, while having enough power to drive both the GoldenEar Triton Fives and KEF R900s to volumes high enough that I could immensely enjoy the high-energy pop sensibility of her performance.
Compared to the Optoma NuForce DDA120 and its predecessor, the NuForce DDA-100 — watershed products offering a very solid 50Wpc of high-quality class-D power, the NuPrime IDA-8 is clearly the superior amplifier. Not only did it provide more power, to better drive floorstanding speakers to party-approved levels; it also had a more refined sound that captured the fine details present in hi-rez recordings. With the IDA-8, there was more weight to the Trondheim Soloists in Thorsen’s recording of early Mozart violin concertos, a difference I could hear even with a lower-rez version (24/96 FLAC) that I played through both amps (the DDA120 can’t handle the 24/352.8 version). The DDA120’s soundstage was also somewhat smaller, with a lack of realistic bite of Thorsen’s bow on her violin’s strings, which made the instrument seem slightly more distant than through the more precise- and immediate-sounding IDA-8.
The IDA-8 even gave the superb combination of Oppo BDP-105 universal BD player ($1199, discontinued) and NAD Masters Series M27 multichannel amplifier ($3999) a run for its money. Incorporating ESS’s most advanced DAC, the ESS ES9018 Sabre32 Reference 32-bit chip, and a high-quality, built-in volume control, the BDP-105 can be used as a high-performing DAC-preamp — and the M27 features NAD’s excellent implementation of Hypex’s Ncore class-D amplifier modules, specified to output 180Wpc into 8 or 4 ohms. The much more expensive Oppo-NAD combo had a cleaner, more open sound than the IDA-8, with even greater bass control. However, although the Oppo-NAD combo was exceedingly neutral, I sometimes found myself preferring the slightly richer, more forgiving sound of the IDA-8. For instance, even though the Oppo-NAD better controlled the driving beat of “White Wedding (Part 1),” from Billy Idol (24/192 FLAC, Capitol), when I really cranked the volume, the guitar could be a little jarring in comparison to the IDA-8. I could happily listen to either of these fine systems for extended periods of time — but for $995, the extreme value and convenience of the NuPrime IDA-8 are undeniable.
Ready for prime time
I love the NuPrime IDA-8. It sounds fantastic, has plenty of power to drive any reasonably efficient loudspeaker to room-filling levels, it’s compact, and, best of all, it costs less than $1000. It also has a built-in DAC that can play hi-rez PCM files with sampling rates up to 384kHz, as well as DSD files. The Optoma NuForce DDA120 is still an excellent value at $699, but for me, the significant step up in performance with the IDA-8 is well worth $296 more. Pair it, as I did, with such speakers as the GoldenEar Triton Five — or, perhaps, the more expensive but still extremely high-value Revel Performa3 F206 or KEF R500, both of which come highly recommended by Doug Schneider — and a true high-end audio system based on the IDA-8 may be more affordable than you think. In fact, the NuPrime IDA-8 was so good that it seemed almost a shame to extract it from my reference rig and reinstall it in my second system, where it will remain as my new budget reference amplifier. It’s one of the best deals available in audio today.