Интегральные усилители — Nuprime Audio IA-9X

The IA-9X is a discontinued integrated amplifier by the Oregon company NuPrime Audio, priced at USD 1,199 and built for analogue systems. It includes an MM phono stage and combines two NuPrime circuits, Only Distortion Cancellation (ODC) and Harmonic Generation, with a front-panel toggle that selects ODC alone or ODC with added harmonics.

Key specs that matter

Rated output is 90 W RMS into 8 ohm and 145 W RMS into 4 ohm, with peak figures of 100 W and 160 W. Inputs comprise one phono pair, two stereo RCA pairs and one stereo XLR pair, and there are two speaker outputs. Gain is 24.61 dB, sensitivity to rated power is 1.5 Vrms, input impedance is 47 kohm and output impedance is 20 milliohm. Typical THD and signal-to-noise are 0.0014 percent and 95 dB at 5 W, and 0.003 percent and 105 dB at 50 W. Frequency response runs from 10 Hz to 50 kHz at -3 dB.

Engineering and use context

NuPrime pitches the ODC setting for studio monitoring and the added harmonics for relaxed listening. The ODC Class D PWM section uses two new NuPrime amplifier modules rated at 0.0014 percent THD, built around the MUSES8820 op-amp in a delta sigma circuit. The Harmonic Generation circuit uses Class A transistors. NuPrime specifies custom audio capacitors totalling 13,200 uF and 25 A bridge rectifiers in the supply. Source switching at input and output uses audio relays. Volume is an analogue circuit under digital control with 99 steps and remembers its setting when power is off. The phono section is the PRA-9X, a two-stage RIAA amplifier also based on the MUSES8820. It offers load resistance of 32, 47 or 100 kohm and capacitance of 100, 220 or 320 pF, with MM sensitivity of 4.0 mV at 1 kHz and 65 dB of gain from phono input to line output at maximum volume. Standby draw is 4.6 W on 115 V and 3.3 W on 230 V, and idle draw is 13.5 W and 11.5 W. The chassis measures 60 x 235 x 281 mm and weighs 3.8 kg, and the carton weighs 5 kg. Warranty cover lasts one year. A 5 A slow-blow fuse protects the mains input.

Pairing

The adjustable resistance and capacitance of the phono input are meant for matching different MM cartridges. 12 V trigger input and output jacks on 3.5 mm three-pin plugs let the IA-9X switch other components on and off.

Alternatives

The NuPrime IDA-8 combines amplification with a DAC for USB, coaxial and optical sources, rated at 100 W per channel into 8 or 4 ohm.