NAD C328 graphite

The NAD C328 is a stereo integrated amplifier delivering 2 x 50 watts. It uses hybrid digital amplification and includes a 24-bit / 192 kHz digital-to-analog converter, aptX Bluetooth connectivity, as well as a phono preamplifier compatible with MM cartridges. Designed in continuity with the brand’s previous models, including the 3020, the C328 follows an approach focused on functional simplicity and sound reproduction.

A minimalist design serving the essentials

The C328 adopts a radically understated design that immediately reflects NAD’s priorities. Its matte graphite-gray front panel features only the strictly necessary controls: a standby button, a 6.35 mm headphone jack, two source selection buttons, a central display, a Bass EQ button, and a substantial volume knob with a particularly smooth feel. This knob, made of ABS plastic, drives a damped rotary encoder rather than a traditional potentiometer, allowing 0.5 dB volume steps.

The display, though modest in size, is a novelty at this price point. It indicates the active source and briefly shows the volume level before fading, leaving only the name of the selected input visible. This pared-down approach is echoed in the total absence of traditional tone controls, replaced by a single Bass EQ function that applies a boost of about 7 dB centered at 80 Hz.

The steel chassis, of minimal yet sufficient thickness, measures 435 mm wide, just 70 mm high, and 285 mm deep. Weighing 4.9 kg, the C328 seems almost slight compared to traditional class AB amplifiers. This lightness is explained by the adoption of a high-efficiency switching power supply and class D amplification, technologies that drastically reduce bulk while improving energy efficiency.

A high-resolution DAC for all your digital sources

The built-in digital-to-analog converter is based on the Cirrus Logic CS42528 chip, a high-performance audio codec capable of handling PCM signals up to 24-bit/192 kHz. This chip integrates eight D/A converters and two A/D converters, using multi-bit delta-sigma technology. With a dynamic range of 114 dB and total harmonic distortion of -100 dB, the CS42528 delivers performance that far exceeds the needs of most current digital sources.

NAD implemented this DAC using a dual differential design, virtually eliminating noise and distortion. The four digital inputs—two coaxial and two optical—allow simultaneous connection of multiple sources such as a TV, game console, CD player, or streamer. The integration of an S/PDIF receiver with clock recovery and automatic format detection simplifies everyday use.

aptX Bluetooth connectivity is a particularly successful addition. The supplied external antenna, although sizable once installed, ensures optimal range and connection stability. The aptX codec enables CD-quality audio transmission, turning any smartphone or tablet into a quality music source. More originally, the C328 can also operate as a Bluetooth transmitter, allowing you to listen to any connected source with a compatible wireless headset.

Versatile inputs tailored to the modern user

The rear connections reflect evolving listening habits. The three analog RCA inputs are cleverly named “TV,” “Streaming,” and “Phono,” abandoning the traditional “CD” or “Tuner” labels. This pragmatic approach acknowledges that traditional physical sources are gradually giving way to connected devices and streaming services.

The built-in MM phono preamp deserves special mention. In a market where this feature is gradually disappearing, NAD maintains its commitment to vinyl enthusiasts. The phono circuit delivers remarkable performance with a signal-to-noise ratio above 95 dB and precise RIAA equalization. Independent tests confirm that this preamp rivals external models sold in the 150–200 euro price range.

The mono subwoofer output is the only concession to home theater setups. This unfiltered output allows the addition of a subwoofer without affecting the signal sent to the main speakers. The built-in headphone amplifier, with an output impedance of only 11 ohms, can comfortably drive most headphones on the market, including the high-impedance models used in studios.

Hybrid Digital Stereo Amplifier

• Continuous output power 2 x 50 W (8 Ω, 20 Hz - 20 kHz)
• IHF dynamic power
  • 80 W (8 Ω)
  • 150 W (4 Ω)
  • 210 W (2 Ω)

Measurements

• Total harmonic distortion < 0.03% (20 Hz - 20 kHz)
• Signal-to-noise ratio > 95 dB (A-weighted)
• Damping factor > 100 (8 Ω, 20 Hz - 20kHz)
• Frequency response ± 0.3 dB (20 Hz - 20 kHz)
• Channel separation > 85 dB (1 kHz) - 70 dB (10 kHz)
• Voltage gain 37dB
• Input sensitivity 250 mV (rated power)
• Headphone output impedance 11 Ω

Connectivity

• 2x Coaxial digital inputs
• 2x Optical TOS inputs
• 2x RCA CINCH analog inputs
• 1x Phono MM input
• 1x Subwoofer output
• 1x Front-panel amplifier and headphone output
• 1x Removable IEC power cable
• Bluetooth aPtX
• Bass EQ
• Bluetooth antenna
• Gold-plated connectors

General

• IR remote control included
• Standby power consumption: < 0.5 W
• Dimensions (W x H x D): 435 x 70 x 285 mm
• Net weight / Packed weight 4.9 kg / 5.9 kg