NuPrime DAC-10H DAC/Pre and ST-10 Power Amplifier

True High Performance for Less

Equipment report
Solid-state power amplifiers,
Digital-to-analog converters
NuPrime Audio DAC-10H,
NuPrime Audio ST-10
NuPrime DAC-10H DAC/Pre and ST-10 Power Amplifier

In 2014, NuForce’s cofounder, Jason Lim, with backing from the OEM factory, bought the assets of NuForce’s high-end division, obtained the rights to NuForce technologies, and formed NuPrime Audio, Inc. Shortly afterward the NuForce company was sold to Optoma.

NuPrime’s first offering, the IDA-16 integrated amplifier, was reviewed by Vade Forrester (Issue 252). He concluded that, “I wouldn’t be ashamed to put it on a shelf next to the fanciest component.” NuPrime’s latest, the $1795 DAC-10H DAC/Pre and the $1595 ST-10 basic power amplifier, are slightly more expensive than the $2600 IDA-16 integrated amplifier, but promise an even greater level of sonic refinement and flexibility. How do they stack up in this highly competitive price range? Let’s see.

The DAC-10H
Although the DAC-10H is only 2.4" high by 8" wide by 14" deep, which corresponds to roughly half the width of a “full-sized” component, it packs a lot of features and performance into a small package. The DAC section is built around the ESS Sabre Reference ES9018 32-bit DAC chip. According to NuPrime this DAC chip can deliver 135dB signal-to-noise with -120dB total harmonic distortion levels. To reduce time-domain errors the DAC 10H utilizes symmetrical signal processing combined with asynchronous data transfer. It supports PCM up to 384/32 and DSD up to 256.

On the analog side, the DAC-10H has borrowed from the NuForce P-20 preamplifier the stepped, thin-film switched-resistor ladder network for controlling volume. This device uses a MUSES chip combined with a proprietary look-up table to ensure that only a single resistor is in the signal path at any given volume setting. The volume adjustment is in 0.5dB increments and is displayed via a 0-to-99-numbered system on the front panel. Comparing different sources using these precise and repeatable volume adjustments was a pleasure.

In addition to the 99-step volume control, the DAC-10H also has dual gain settings for its outputs. The single-ended RCA output can have a maximum voltage of either 2 or 4 volts, while the balanced XLR outputs have 4 and 8 volt levels. The headphone amp also has two levels for its balanced and unbalanced output to allow for different headphone sensitivities and impedances.

In its input stages the DAC-10H uses ultra-low-noise JFETS with independent left and right power supplies that come from a multi-rail toroidal transformer coupled to a linear power supply. This helps achieve a crosstalk attenuation specification of at least 93dB at 1kHz.

The DAC-10H has two headphone outputs: a single-ended and a balanced connection. Both have the same output impedance of less than 10 ohms. The balanced headphone circuit uses an OPA2134 op-amp as a buffer for the pair of NuPrime-branded IC chips used to drive the output.

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