Full review in image hifi magazine (Germany), Issue 2/2009
Accuphase Stereo Phono Amplifier C-27
by Dirk Sommer [Editor in Chief]
Which dedicated follower of analogue music reproduction would have ever dreamed of this 20 years ago? The Japanese noble maker Accuphase is for the first time presenting a separate, extremely elaborate phono/equalizerpreamplifier.
It was in the end of the year 2001, during the celebrations for the 25th anniversary of P.I.A. [the Accuphase distributor in Germany], in a time when many, in particular U.S. high-end manufacturers have put an emphasis on home cinema - no longer a big issue today, eh? - when also Saito-San, in his capacity as Vice-President of Accuphase, unreservedly stood up for the two-channel stereo rendition of music.
How serious this commitment was meant is, amongst other things, documented by the analogue tuner T-1000, which was to receive an image hifi award, and the stunning CD player DP-500. Accuphase actually never bothered about alleged future trends but rather had faith in those audiophiles who would like to acquire the very best component for the playback of the currently widespread formats and media and, yes, Accuphase succeeded.
To this date analogue aficionados had a choice among various phono boards to suit their preamplifiers or integrated amps from Accuphase. Now this maker is trying to meet the ever so growing demands of vinyl lovers with sophisticated audio components at home by launching a phono/equalizer-preamplifier which is capable of processing the signals of up to three pickup cartridges, whereby it doesn't matter if the cartridge is of the moving-magnet or moving-coil variety. Each input can be configured accordingly. Yet this is not carried out by simply switching an additional amplification stage in the signal path on or off, like is the case with nearly any other competitive phono preamplifier. No way, in the C-27 Accuphase allows itself the luxury of providing two independent amplification stages, one completely optimised for MM, the other one for MC.
Moving-magnet pickups generate an output voltage which is about ten times higher than the output voltage of a "normal" moving-coil pickup and they are usually designed for a load impedance of 47 kOhm. Therefore, three FET buffer amplifiers
(x2) with high input impedance, arranged in parallel configuration, are taking care of the incoming signal before it is handed over to six likewise parallel-configured differential amplifiers in a push-pull circuitry. In addition to the standard 47 kOhm, this amplifier stage also offers a load impedance of 1 kOhm and 100 kOhm, which is activated by relays and accordingly selected by means of a rotary knob on the front panel.
The substantially weaker MC-signals are boosted via eight parallel differential amplifiers in order to ensure a low load impedance as well as an extremely high signal-to-noise ratio which is oh so important for the operation of pickups with moving coil technology. Load impedance can conveniently be selected, again by means of a rotary knob, whereby 3, 10, 30, 100, 300 and lastly 1000 Ohm are provided for
experimentation. For each amplifier section, the gain can be augmented by 10 dB
and then a subsonic filter can be activated by simply pressing a button. It goes without saying that the C-27 also features a memory facility for load impedance,
overall gain, subsonic filter and, last but not least, MC- respectively MM-mode of operation. All this can be programmed for each input.
The MM- and MC-amplifier of each channel share one circuit board made of
