Accuphase C-2810 Brochure

m Revolutionary AAVA volume control m Fully modular construction
with individual left/right amplifi er units m Separate R-toroidal power transformers for left and right channels m Selectable preamp gain m Printed circuit boards made from Tefl on material m Logic-con- trolled relays for shortest signal paths m Optional support for analog record playback m Massive cabinet made of persimmons wood
The C-2810 inherits the superb design technology of the C-2800 but takes another signifi cant step for­ward. The new model employs only top-quality parts selected after extended listening tests and features a further improved AAVA (Accuphase Analog Vari­gain Amplifi er) volume control. How a preamplifi er handles listening level adjustment has a decisive infl uence on its performance and sound. AAVA is an innovative concept that differs radically from conventional variable-resistor type volume controls. In AAVA, amplifi cation and volume control are fully unifi ed, eliminating all mechanical contact points. Pure analog processing ensures optimum perfor­mance and superb sound. Another benefi t of AAVA is that its performance and sound quality will remain undiminished for many years to come.
The power supply section of the C-2810 employs two separate R-toroidal transformers, one for each channel. Filtering capacitors and all other parts of the power supply are also duplicated for left and right. What’s more, all unit amplifi ers such as for input buffer, AAVA, and balanced output are also entirely separate for the two channels, arranged on a high­quality motherboard. This fully monaural construction prevents unwanted crosstalk and interaction both on the electrical and the physical plane. The result is utterly stable playback sound of impeccable quality. Logic relay control is used for source switching to implement the shortest possible signal paths. Each input position allows individual phase selection. The printed circuit boards are an important element of a preamplifi er both regarding electrical performance as well as sound quality. In the C-2810, these are made from a Tefl on material with low dielectric constant and minimum loss. Every aspect of this top-notch analog preamplifi er has been honed for optimum sonic performance. The overall result is a fl agship product that represents the best that Accuphase has to offer.
Meet the new fl agship model – Preamplifi er with further im­proved revolutionary AAVA volume control. Complete dual mono construction with two R-toroidal power transformers. Modular amplifi ers using printed circuit boards made from Tef­lon. Independent phase selection for each input position. Phono Equalizer Unit allowing high-quality playback of analog records.
n Logic-controlled relays as-
sure high sound quality and long-term reliability
The strategically placed relays of the C-2810 prevent any signal degradation that could occur if the signal has to travel a long way for input and output connection and function switching. Optimum signal fl ow is maintained at all times.
n Ideal power supply uses “R-toroidal transformers” in fully
monaural confi guration
Each transformer is housed in a dual-wall enclosure with a glass fi ber core and strong resin coating. In addition, epoxy fi ller with superior vibration-damping and insulation characteristics is used, resulting in highly effective triple insulation.
n Printed circuit boards in signal transmission circuitry made
from Tefl on (glass fl uorocarbon resin substrate) with low dielectric constant and low loss
* Tefl on is a registered trademark of DuPont USA.
n Selectable preamp gain
The overall gain of the preamplifi er can be set to 12 dB, 18 dB, or 24 dB. (Standard position is 18 dB.)
n EXT PRE function allows use of external preamplifi er n Independent phase selection for each input position
The selected phase setting is memorized for each input position separately. The on/off status of a LED indicator shows the respective setting.
n Versatile input and output connectors (inputs shown as
character display)
Dedicated headphone amplifi er optimized for sound quality
n n Versatile features:
m Provisions for recording/playback/copying with two recorders m
Loudness compensator augments bass and treble at low listening
volume
m
Attenuator
m
Subsonic fi lter removes ultra low frequency noise
n Massive cabinet made of persimmons wood
Balanced inputs and outputs Unbalanced inputs and outputs
R-toroidal transformer
Gain selector
EXT PRE function and phase selector button,
18
16
14
12
10
8
6
4
Response in dB
2
0
-2
-4
-6 10 100 1k 10k 100k
Loudness compensator characteristics
COMP.1
LOUDNESS COMPENSATOR: ON
COMP.2
with LED indicators
COMP.2
COMP.1
Frequency in Hz
BUFFER
INPUT
BUFFER
Input music signal
AAVA (Accuphase Analog Vari-gain Amplifi er) volume control
AAVA is a radically different volume control principle that does not use variable resistors and provides top-notch performance and sound quality. Because the music signal does not pass through variable resistors, it is not affected by changes in impedance. This means that high signal-to-noise ratio and low distortion of the signal are maintained at any volume control setting.
n AAVA resolution
AAVA adjusts the listening volume by means of 16 weighted V-I converter amplifi ers which are controlled by current switches. The number of possible volume steps set by the combination of these converter amplifi ers is 2 to the power of 16 = 65,536.
n AAVA ensures high S/N ratio and uniform frequency
response
With conventional volume controls, the impedance increases signifi cantly at settings that correspond to normal listening lev­els, thereby leading to increased noise. With AAVA, there is no change in impedance and consequently no deterioration of S/N ratio. Frequency response also remains totally uniform. Chang­ing the volume with AAVA does not mean introducing noise or detracting from the high performance of the amplifi er.
n No more left/right tracking differences or crosstalk
Because AAVA is an electronic circuit employing fixed-value resistors, there is virtually no left/right tracking error also at low volume levels. Since channels can be kept separate, crosstalk also does not present a problem.
Conversion into current with 16 weighting stages (1/2–1/2
16
)
16 current switches (65,536 possible combinations)
Volume Balance
CPU
Attenuator
CPU detects position of volume knob and operates current on/off switches according to knob position
Operation principle of AAVA in
C-2810
I-V Converter
Reconversion of current into voltage
Current values are added
37
28
19
Volume knob is turned and position is detected
OUTPUT
GAIN
VOLUME
5
46
MIN MAX
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