Description
Accuphase C-57 Phono Preamplifier
Fully balanced configuration for an ideal phono equalizer amplifier. The C-57’s configuration provides a fully balanced phono equalizer from input to output. The combination of a high precision equalizer amplifier and a dedicated MC/MM headamplifier fully optimized for the cartridge characteristics creates a highly accurate phonoequalizer. As a first, the MC head amplifier uses ANCC to further improve noise performance. Dedicated MC phono balanced inputs allow for balanced connections with record players. The C-57 combines only the best technological advances to extract the full potential of analog discs.
Innovation ‒ At the leading edge of technology
■ ANCC significantly reduces distortion and noise (Accuphase Noise and distortion Cancelling Circuit) ANCC uses a secondary amplifier to cancel out distortion and noisefrom the main amplifier. Complementing the main amplifier, the MC head amplifier is equipped with ANCC to cancel out noise and distortion within the constituent components. The secondary amplifier’s balancedlow-noise amplifier further heightens performance.
■ Monaural construction. Not only the head amp and equalizer amp, but also the toroidal transformer, smoothing aluminum electrolytic capacitors, and regulated power supply circuitry are all separated, preventing interference between channels. This monaural construction enhances channel separation.
■ Extremely low noise and highly accurate equalizer characteristics. The amplification circuitry features a two-stage design with a low-noise MC/MM head amplifier and a high-precision equalizer amplifier. 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 equalizer amplifier is kept to a minimum, resulting in excellent low-noise performance combined with extremely accurate equalization characteristics.
■ Fully balanced configuration. The C-57 employs a fully balanced configuration which reliably shuts out external noise. A fully balanced configuration is achieved by subjecting the output signal from the cartridge to balanced amplification (amplifying only the difference between two signal inputs) in both the head amplifier and equalizer amplifier.
Sound quality ‒ Simply aiming for the best
■ Newly developed low-noise regulated power supply circuitry unaffected by load fluctuations. In a phono equalizer amplifier that handles extremely weak signals, the quality of the power supply plays a critical role. The smoothing circuitry employs four 25 V/15,000 μF high-capacitance filter capacitors per channel, specially selected for their sonic properties. It also includes adedicated low-noise power supply for the ANCC.
■ Dedicated balanced MC phono input. A dedicated balanced MC phono input enables connections with analog players via a balanced phono cable.
- MC head amplifier with ANCC
- Low-noise fully balanced configuration
- One dedicated balanced MC phono input and three sets of regular phono inputs
- Separate settings memory for each input position
- Balanced and line level output connectors
- Polarity selector for balanced output
- Monaural construction layout
- Low-noise regulated power supply circuitry unaffected by load fluctuations
- High-accuracy phono equalizer with RIAA deviation of only ±0.3 dB
- Load impedance settings for seven MC and three MM phono cartridge types
- MC: 10/30/60/100/200/300/1k ohms
- MM: 1/47/100 kilohms
- 7-segment load impedance LED display
- Gain selector for low-output phono cartridges
- Subsonic filter ON/OFF selector
- Disc equalizer assembly using glass fiber cloth fluorocarbon resin PCB with low dielectric constant and low losses
- High-capacitance 25 V/15,000 μF filter capacitors
- Toroidal power transformer
- Aluminum top plate with hairline finish
- Elegant side panels with natural wood grain finish
- High-carbon cast iron insulators for superior vibration damping
