In its relatively short existence, NuForce has become a household name among audiophiles. The Northern California based company has introduced many landmark products, including Class D monoblock amplifiers, desktop and portable devices, DACs, headphone amps, and a host of other interesting offerings. They have also delved into home theater, and wireless audio.
NuForce is also known for continuously improving its products and offering cutting edge technology. From my experience, the products are well designed, well built, and smartly use a combination of native brain power and overseas manufacturing. NuForce has also priced many of their products within reach of any budget. On the flip side, they also make reference level gear at higher price points.
I received in for review one of NuForce’s newest products, the DDA-100 integrated amplifier. “DDA” stands for direct digital amplifier. This is a cutting edge design used by just a few other manufacturers, including NAD and Wadia. Essentially, it is a “power” DAC that can drive your speakers directly. Equipped with only digital inputs, it converts the signal to analog only at the last stage, at the speaker binding posts. According to NuForce, “the DDA-100 doesn't require the typical DAC stage found in most of today's digital audio products. Rather, its PWM power amplifier stage is modulated directly by the incoming signal, and the digital-to-analog conversion takes place at the speaker outputs. In effect, the PWM power amplifier stage operates as a power DAC.” Essentially, the digital inputs feed PCM signals straight to the Class D amplification section with no D/A conversion step in between. Class D is also known as PWM or Pulse-Width Modulation.
The DDA-100 is rated at 50 Watts RMS into 8 ohms and 75 Watts RMS into 4 ohms. There are four digital inputs, two optical, one coaxial, and one USB 2.0, listed as “adaptive”. Surprisingly, there is also an optical output. There are set of quality binding posts, and IEC inlet, and a supplied miniature sized, full function remote. The unit is available in black or silver. The review sample was supplied in black.
There are a few minor quirks of which a potential buyer must be aware. The optical and USB inputs accept maximum sample rates of 96 Khz, and the coax input accepts sample rates from 44.1 khz to 176.4 khz, but curiously not 192 Khz. Odd, since there is very little source material available at 176.4, yet quite a few 192 offerings at HDTracks and other download sites. However, the reality is this will hardly be a consideration for virtually all prospective buyers of the DDA-100.
Set Up & Listening
The DDA-100 is a real space saver of a component, barely bigger than a cigar box, yet it is well put together. I used it with a pair of Harbeth Compact 7 ES3 speakers, which are of average sensitivity, tethered with Transparent "The Wave" speaker cables. I used a Mojo Audio power cord, and sources were a Squeezebox Touch and an Onkyo CD player. Remember, there are no analog inputs, so I used TosLink with the Squeezebox, and coaxial with the Onkyo.
From the first few notes of the first album I cued up, I realized I was dealing with a product that was going to defy expectations. Specifically, there was more resolution and more musical information flowing through the speakers then from any component I have reviewed at anywhere near this price point. After just a few hours, I felt NuForuce had successfully made a case for the direct digital amplifier. Mind you, I was told the amp would need a good 100 to 150 hours of break before it sounded its best, and this was absolutely accurate.
The first 25 hours or so, there was a slight dryness to the treble, but that completely disappeared thereafter, and I heard nothing but silky smooth high frequencies that sounded as natural as any DAC I have had in the system. Acoustic guitars were all steel and wood, drums were woody in tone, and piano was amazing present and dimensional. The soundstage was amazingly wide, with the mix spread across the room, when the recording allowed.