Accuphase C-47

Accuphase C-47: A Reference Phono Preamplifier

The C-47 is the first phono preamplifier in the Accuphase series to offer a fully balanced configuration from input to output. This technical innovation provides increased resistance to external noise, ensuring sound reproduction of exceptional purity. The C-47 incorporates a dedicated preamplifier, optimized for the specific characteristics of moving magnet (MM) and moving coil (MC) phono cartridges, as well as a high-precision equalizer amplifier. This combination ensures precise RIAA equalization with minimal noise, offering audiophiles a rich and deeply satisfying listening experience.

Design and Aesthetics: Timeless Elegance

True to Accuphase’s signature aesthetic, the C-47 features a design that is both modern and retro. Its brushed aluminum front panel, in the brand’s characteristic champagne color, perfectly complements the black brushed aluminum top plate. The solid wood side panels, with their natural wood grain finish, add an extra touch of elegance. The orange LED display and analog controls enhance the vintage look of the device, recalling the golden age of hi-fi while incorporating cutting-edge technologies.

Connectivity and Flexibility of Use

The C-47 offers great flexibility in terms of connections. It has a dedicated balanced MC phono input, allowing a balanced connection with high-end turntables equipped with XLR outputs. In addition, three sets of regular RCA phono inputs are available for more classic configurations. On the output side, the device offers both balanced XLR and unbalanced RCA connectors, thus adapting to all types of amplifiers. A polarity selector for the balanced output optimizes compatibility with different systems.

Exceptional Technical Performance

The Accuphase C-47 stands out for its remarkable technical performance. Its high-precision phono equalizer offers an RIAA deviation of only ±0.3 dB, ensuring faithful reproduction of the original signal. The preamplifier provides load impedance settings for six types of MC cartridges and three types of MM cartridges, allowing optimal adaptation to a wide range of cartridges. A gain selector for low-output cartridges and an integrated subsonic filter complete the features, ensuring maximum versatility.

Sophisticated Internal Architecture

The internal design of the C-47 showcases Accuphase’s expertise in high-end audio electronics. The device adopts a fully mono construction, with separate toroidal power transformers for the left and right channels. This approach, combined with a low-noise regulated power supply circuit, ensures optimal channel separation and immunity to load fluctuations. The use of fluorocarbon resin printed circuit boards with low dielectric constant and low loss for the equalizer assembly contributes to signal purity. The gold-plated printed circuit boards reflect the attention to detail.

Precise Adjustments and Customization

The C-47 offers great flexibility in settings to perfectly adapt to any configuration. It features adjustable gains (34 dB / 40 dB for MM, 64 dB / 70 dB for MC) and variable impedances (1K, 47K, 100K ohms for MM; 10, 30, 100, 200, 300, 1K ohms for MC). A 7-segment LED indicator displays the selected load impedance, making adjustments easy. Separate parameter memory for each input position allows for quick switching between configurations.

Build Quality and Reliability

Like all Accuphase products, the C-47 boasts impeccable build quality. The use of handpicked components, such as the 9 bipolar transistors for the MC stage and the 3 FETs for the MM stage, ensures optimal signal processing. The robust construction, with a rigid chassis and high-quality components, guarantees exceptional longevity for the device. The substantial weight of 14.8 kg is a testament to its solid construction.

Audio Performance

• Total Harmonic Distortion (THD): ≤ 0.005% (at 1 kHz, nominal output)
• RIAA Deviation: ± 0.3 dB (10 Hz – 20 kHz) for MC and MM
• Signal-to-Noise Ratio: MC: 97 dB, MM: 108 dB
• Subsonic Filter: -12 dB/octave, 10 Hz

Input Characteristics

• Sensitivity:
  • MC: 1.26 mV 64 dB / 0.63 mV 70 dB
  • MM: 40 mV 34 dB / 20 mV 40 dB
• Maximum Voltage:
  • MC: 5.7 mV 64 dB / 2.9 mV 70 dB
  • MM: 180 mV 34 dB / 90 mV 40 dB
• Maximum Output Level (THD 0.01%, 20 - 20,000 Hz): 8.0 V
• Selectable Impedance:
  • MC: 10 Ω, 30 Ω, 100 Ω, 200 Ω, 300 Ω, 1 kΩ
  • MM: 1 kΩ, 47 kΩ, 100 kΩ
• Signal-to-Noise Ratio:
  • MC: 97 dB
  • MM: 108 dB

Amplification and Output

• Gain:
  • Normal: MC 64 dB, MM 34 dB
  • High: MC 70 dB, MM 40 dB
• Nominal Output: 2 V, 50 Ω

Connectivity

• Inputs: 3 × RCA stereo
• Outputs:
  • 1 × XLR stereo
  • 1 × RCA stereo

General Characteristics

• Power Consumption: 21 W
• Dimensions: 465 mm (W) × 114 mm (H) × 407 mm (D)
• Weight: 14.8 kg