Accuphase C-47 Stereo Phono Preamplifier

Features

Extremely low noise and highly accurate equaliser characteristics

The C-47 features a two-stage design with a low-noise head amplifier optimised to handle MC and MM cartridges and a high-accuracy equaliser amplifier dedicated to the task of equalising the signal. By designing the low noise head amp for high gain (MC: 50 dB, MM: 20 dB), the influence of any noise components in the subsequent equaliser amplifier is kept to a minimum, resulting in excellent low-noise performance combined with super accurate equalisation characteristics.

Fully balanced configuration

As a first in the series, the C-47 employs a fully balanced configuration which reliably shuts out external noise. The output signal from the cartridge is treated as a balanced signal, and the head amp performs balanced amplification (amplifying only the difference between two signal inputs). Balanced signal transmission is maintained also after the head amplifier, and full equalisation is realised by making the equaliser amplifier a balanced type as well.

Low-noise regulated power supply circuitry unaffected by load fluctuations

In a phono equaliser amplifier that handles extremely weak signals, the quality of the power supply has a significant effect on sound quality. The smoothing circuitry employs four 25 V / 15,000 μF aluminium electrolytic capacitors per channel, specially selected for their sonic properties. This generously dimensioned configuration virtually eliminates adverse effects from ripple currents and similar. The use of a regulated power supply circuit with very low noise voltage and excellent handling of load fluctuations further ensures that the power supply does not introduce any noise

Dedicated balanced MC phono input

A dedicated balanced MC phono input makes it possible to handle the signal supplied by the cartridge as a balanced signal. A balanced phono cable can therefore be used for the connection between the analogue record player and the C-47.

Specifications

RIAA Deviation

MC 10-20,000 Hz ±0.3 dB

MM 10-20,000 Hz ±0.3 dB

Total Harmonic Distortion (1 kHz, at rated output)

0.005%

Gain GAIN selector OFF (Normal)

MC 64 dB

MM 34 dB

GAIN selector HIGH

MC 70 dB

MM 40 dB

Input Sensitivity (1 kHz, for rated output)

MC 64 dB 1.26 mV 70 dB 0.63 mV

MM 34 dB 40 mV 40 dB 20 mV

Maximum Input Voltage (1 kHz, 0.005% THD)

MC 64 dB 5.7 mV 70 dB 2.9 mV

MM 34 dB 180 mV 40 dB 90 mV

Maximum Output Level (0.01% THD, 20 - 20,000 Hz)

BALANCED/ LINE OUTPUT 8.0 V

Input Impedance

MC 10 ohms, 30ohms, 100 ohms, 200 ohms, 300 ohms, 1 kilohm

MM 1 kilohm, 47 kilohms, 100 kilohms

Rated Output Voltage, Output Impedance

BALANCED OUTPUT 2 V 50 ohms

LINE OUTPUT 2 V 50 ohms

S/N Ratio, Input-converted Noise

Input shorted (A weighting)

Input         S/N ratio at rated output         Input-converted noise

MC: 64 dB              97 dB                            -155dBV

MC: 70 dB              91 dB                            -155dBV

MM: 34 dB              108 dB                            -136dBV

MM: 40 dB              102dB                            -136dBV

Minimum Load Impedance

BALANCED/LINE OUTPUT 10kilohms

Crosstalk

-90dBor less(IOkHz)

Residual Noise (A-weighted, with input shorted)

GAIN selector OFF (Normal)

MC 28.2 uV or less

MM 7.9 uV or less

GAIN selector HIGH

MC 56.2 uV or less

MM 15.8 uV or less

Subsonic Filter

-12 dB/oGtave, 10 Hz

Power Requirements

120 V, 220 V, 230 V AC (voltage as indicated on rear panel), 50/60 Hz

Power Consumption

21 W

Maximum Dimensions

Width 465 mm (18.31") x Height 114 mm (4.49”)x Depth 407 mm (16.02")

Mass

Net 14.8 kg (32.6 lbs)

In shipping carton 21.0 kg (46.3 lbs)