 Accuphase is a company known best from its amplifiers, then from digital sources – first Compact Discs, and now also Super Audio CD. But somewhere underneath this company cultivated the analog way of thinking. Every integrated amp or preamplifier can be equipped with one of the optional expansion cards – AD-2810, AD-20, AD-10 – being complete gramophone preamplifiers, that you just plug into an empty expansion slot. And earlier this Japanese manufacturer offered fully blown, hi-end models: C-7 introduced in 1979 and C-17 in October 1984. Did you notice the second date? Yes, this was the moment when Compact Disc gained appreciation and found its way into the hearts and homes of audiophiles. Two years later, in 1986, Accuphase entered this “river” with the split DP-80/DC-81 player, and has not revisited the idea of external phono preamps since. Until March 2009, fifteen years after the previous model, when they offered the C-27, a name that suggests relationship to the C-7 and C-17. )
This new preamplifier has the size of a “regular” device and its manufacturing quality is equally precise. This is a solid aluminum front in gold color, heavy chassis and balanced internal structure. As Accu is a company caring for the comfort of users, the preamp is equipped with three inputs, selectable from the front panel, a balanced and an unbalanced output (the circuit is balanced – the cartridges are balanced from the nature, and the mass is the chassis mass) and the load settings are also adjustable from the front panel. The electronic circuit is based on transistors, and the signal is led in many parallel runs. This allowed for incredible measurable parameters: noise for MM (30dB gain) is -110dB, for MC (gain 60dB) -98dB. The RIAA curve deviation is less than 0,5dB in the 10Hz – 100000Hz (for MM) and 0.3dB for MC. THD in the 20Hz – 20kHz range are at 0.002%. So I’ll quote the company page: “Those are outstanding values”. )
Discs used for listening test: SOUND )
The Accuphase preamplifier plays with an incredibly sparkling, balanced sound. It could be even said: delicate. The brass from the Madeleine Peyroux disc had a sweet, slightly rounded taste, although there was a lot of them. C-27 sounds lighter than for example Manley Steelhead or Sensor Prelude IC RCM Audio. Ayon Polaris II (or better said, it’s RIAA section) is much darker and has the gravity point shifted to the upper bass. In general the C-27 treats every disc the same way, it shows their more delicate, very feminine side. Maybe not romantic or lyrical, because this is not about mimicking the tonal balance and timbre to a tube device, but rather “softness”, defined as the lack of harshness, sharp edges, etc. This was clear on the Madeleine Peyroux disc, as for once it is a Mobile Fidelity re-edition, known for that kind of sound, and secondly the music itself provokes it. The digital version of this disc is darker, more tubey, but also lacking half the resolution vinyl provides. And yet the LP played through the C-27 seemed softer and lighter, despite the Accuphase being lighter than most of the hi-end preamplifiers known to me. )
And it is not a “sharp” device. Rather ‘soft’, rather ‘delicate’, rather ‘sparkling’. This is how brass sounds. Those recorded on Czesław Niemen disc Katharsis, in the closing piece are a good example. But those were – due to the cutting process and vinyl type – significantly reduced by Polskie Nagrania. A part of the spectrum is just not there. But when we take a bright cartridge, or a brighter preamplifier, where the treble ‘sings’ louder from time to time, then some artifact treble sounds can be heard. And those should not be there! I listened to that disc with different cartridges and preamps, so I am sure about what I am talking here. And the C-27 only confirmed this opinion. Although there is a lot of higher midrange and treble in it, nothing was added to the sound, nothing was generated, what would not have been found on the disc itself. )
The midrange is creamy. This is the best description to be used in that case. This subrange is smooth, fluent, like cream in a cake. Frankly speaking, the way this device sounds resembles much the line preamplifier from this manufacturer, the C-2810. Interesting enough, the stronger top of the C-27 will be the key to align it with the top Accu system based on the mentioned C-2810 and the P-7100 power amplifier (actually a very good set). Then we will get everything we would like to, and the timbre of the gramophone preamplifier fits well in the smooth sound of that system. )
One of the most important characteristics (assets) of the C-27 is the easiness of changing the parameters of the load and gain. Frankly speaking dynamics was always better with higher gain, so I recommend to listen to cartridges with an output voltage higher, than usual. I would not recommend to pair the C-27 with the cartridge Sumiko Palo Santos Presentation, as this, while brilliant, accents on the treble, what is not desirable here. Without problems we can fit the cartridges from Denon, like the DL-103SA, Celebration II Sumiko or Koetsu Rosewood Signature. When we would like to improve dynamics, then something from Dynavector or Grado should be used. But we need to be careful not to exaggerate with the treble. Because this is not a universal preamplifier, which we could fit easily in any system. Like every hi-end device it requires us, to think about the application. Then we can get an incredibly creamy, vivid sound with a nice characteristic. This is not a universal sound, but has all the assets of top hi-end. And this is what this all is about here, isn’t it? DESCRIPTION )
C-27 is a gramophone preamplifier from the Japanese company Accuphase, capable of working with MM and MC cartridges. This is a full sized, expensive product, made exactly like all the other devices from that manufacturer, what can be seen in the internal details worked out fully, as well as on the outside – it has a golden front panel made from a thick slab of aluminum, with a plastic plate in the middle, covering all the LEDs. We can connect three tonearms to the preamp at once, and those can be switched by means of a selector placed on the front panel. Similar selectors are for choosing the loads – three for MM and six for MC: 1kΩ, 47kΩ, 100kΩ (MM), 3Ω, 10Ω, 30Ω, 100Ω, 300Ω, 1kΩ (MC). Unfortunately the capacitance cannot be adjusted. We can also use a subsonic filter (it is better not to use it) and adjust gain. On the back we have three nicely looking inputs, each with a dedicated ground pin, and two outputs – unbalanced RCA and balanced XLR. Traditionally the ‘hot’ pin is nr. 3. There is also a IEC power socket. The device is placed on splendid feet from high carbon steel. )
The block diagram shows, that in the input we have a section with resistors for the input load, then an active stage for MC cartridge amplification, then a subsonic filter and finally the MM amplification section. The correction section is made using a feedback loop, called NFC. The whole circuitry is made using transistors. The PCBs are from Teflon, with gold plated traces. The MM and MC sections are separate. Both are built around the same concept: in the beginning we have three pairs of FET transistors, working as buffers in a parallel setting MCS++, then six (or eight in the MC section) parallel bipolar transistors, allowing for sufficient gain. Running the signal in parallel allows for reducing the noise levels to extremely low values. Like I wrote earlier, the correction circuit is made as a feedback loop for the MM section.
CDs FROM JAPAN  |
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