Phonostages — Accuphase C-57

The Accuphase C-57 is a top phono preamplifier from the Japanese brand, a reengineered successor to the C-47, which in turn replaced the C-27, the first Accuphase phono stage, launched in 2008. Accuphase calls the C-57 the culmination of its phono equaliser amplifiers, a fully balanced dual-mono design meant to work with a wide range of cartridges.

Key specs that matter

MC load impedance is switchable between 10, 30, 60, 100, 200, 300 and 1k ohms. The 60-ohm setting is new to this generation and was added for fine adjustment with low-impedance moving-coil cartridges. MM load options are 1k, 47k and 100k ohms. Equivalent input noise on the MC input is -156dBV, 1dB lower than on the C-47. RIAA deviation is guaranteed within 0.3dB from 10Hz to 20kHz, helped by hand-selected high-precision resistors and capacitors. The unit measures 465 x 114 x 407mm and weighs 14.8kg.

Engineering and use context

The MC head amplifier uses the Accuphase Noise and distortion Cancelling Circuit (ANCC), applied there for the first time in the brand's phono range. A secondary balanced low-noise amplifier cancels the noise and distortion generated by the main amplifier stage. The equaliser circuit board is made from glass-fibre-cloth fluorocarbon resin, the same material used in the top Accuphase preamplifiers, with a lower dielectric constant and lower loss than standard FR4 fibreglass, which keeps the RIAA-setting component values stable with temperature and protects high-frequency signal integrity. Dedicated balanced MC inputs allow a balanced connection from the cartridge. The dual-mono layout extends to the power supply, with separate toroidal transformers, smoothing capacitors and regulators for each channel. The champagne-coloured aluminium front panel is flanked by natural wood side panels, with rosewood among the options.

Pairing

The range of load and gain settings on both MM and MC inputs covers most cartridges without extra devices. The balanced MC inputs make most sense with a turntable and tonearm already wired for a balanced connection. Accuphase also makes preamplifiers that follow the same balanced design approach and complete the signal chain.