Accuphase C-2810
¥ 1,150,000 (released in June 2006)
Commentary
A control amplifier equipped with an advanced AAVA volume control as a successor to the C-2800.
The volume section uses AAVA (Accuphase Analog Vari-gain Amplifier) volume control.
The AAVA consists of 16 weighted V-I conversion amplifiers and a current switch. The volume is controlled by switching 16 electronic switches. This configuration enables the V-I conversion amplifier to combine 2 to the 16th power = 65,536 steps. The switching control is controlled by the CPU so that the knob position and volume are the same. The current value obtained by the V-I conversion amplifier is combined and converted by the I-V converter to return the voltage.
Conventional variable resistor volume adjustment increases impedance and noise at the volume position used. However, AAVA is not affected by impedance change, so it does not degrade the S/N ratio and does not change the frequency characteristics. It is also composed of electronic circuits and uses fixed resistors, so there is almost no difference in volume between right and left even at a minute level. Moreover, crosstalk between channels is almost eliminated because each channel can be made independent.
Because the AAVA is an electronic circuit that integrates an amplifier and volume control, it has a simple electrical structure, which reduces the deterioration of performance and sound quality over time, and maintains high long-term reliability.
By using the AAVA to balance the left and right volume and to provide an attenuator, we have achieved a simple configuration that does not require any extra circuitry.
The circuit configuration is fully mono-construction.
The C-2810 has separate power transformers on the left and right sides, and a group of unit amplifiers that make up amplifier circuits such as filter capacitors, input buffers, AAVA, and balance output are arranged on the motherboard for the left and right channels, which prevents electrical and physical interference between the amplifiers.
An R-toroidal transformer is mounted independently on the left and right sides of the power supply.
The exterior of this transformer uses glass fiber as a core material and has a three layered structure consisting of a two layered case made of strong resin material and an epoxy filler.
The input / output circuit adopts a logic relay control method to configure the shortest and straight signal path.
For the printed circuit board of the signal transmission circuit, Teflon substrate (glass cloth fluorine resin substrate) with low dielectric constant and low loss is used.
Gold plating is applied to the copper foil surface of the board.
The gain of the entire preamplifier can be selected from three levels.
Equipped with an EXT PRE function that can be switched to an external preamplifier.
It is possible to set and store the phase for all input positions.
The setting can be checked by turning the LED on / off.
It has a built-in dedicated headphone amplifier circuit that emphasizes sound quality.
You can record and play on two recorders, and copy each other.
Equipped with a compensator, it can compensate for the lack of volume of low and high sound.
Equipped with a subsonic filter to cut out ultra-low frequency noise.
The input and volume level can be displayed in text on the display.
The display can be turned off.
Uses a Persimmon case with a finish.
It comes with a wireless remote control, and you can adjust the volume and change the input selector.
The dedicated phono equalizer unit AD-2800 can be added as an option sold separately.
The AD 2800 uses a Teflon base material (glass cloth fluorine resin base material) and is stored in an aluminum case to minimize the influence from the outside. A DIN standard connector is used for connection with the body.
The AD-2800 can be used for C-2800, C-2400, C-290 and C-290V, and the AD-290/AD-290V phono equalizer units used for C-290/C-290V are compatible and can be used for C-2810.
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Model Rating
| Analog disk characteristics show when AD 2800 is added. | |
| Type | Stereo control amplifier |
| Frequency characteristic | Balanced/Unbalanced input: 3 Hz ~ 200 kHz + 0 -3.0 dB 20 Hz ~ 20 kHz + 0 -0.2 dB AD MM/36dB, MC input : 20 Hz ~ 20 kHz ± 0.2 dB AD MM/30dB input : 20 Hz ~ 20 kHz ± 0.3 dB |
| Total harmonic distortion factor | 0.005% |
| Input Sensitivity (Rated Output / 0.5 v Output) / Impedance | AD MM/30dB : 8.0mV/2.0mV/47k Ω AD MM/36dB : 4.0mV/1.0mV/47k Ω AD MC/62dB : 0.2mV/0.05mV/10 Ω, 30 Ω, 100 Ω switching AD MC/68dB : 0.1mV/0.025mV/10 Ω, 30 Ω, 100 Ω switching Balanced : 252mV/63mV/40k Ω Unbalanced : 252mV/63mV/20k Ω |
| Rated Output / Impedance | Balanced, Unbalanced output : 2V/50 ohm Rec (at AD input) : 252mV/200 Ω |
| S/N (Input Short-A Correction (at Rated Output) / EIA) | AD MM/30dB input:95dB/91dB AD MM/36dB input:89dB/92dB AD MC/62dB input:80dB/87.5dB AD MC/68dB input:75dB/88.5dB Balanced/Unbalanced:111dB/110dB |
| Input conversion noise (input short A correction) | AD MM/30dB input:-137dBV AD MM/36dB input:-137dBV AD MC/62dB input:-154dBV AD MC/68dB input:-155dBV Balanced/Unbalanced:-123dBV |
| Maximum output level | Balanced, Unbalanced output : 7.0 v Rec (at AD input) : 6.0 V |
| Line Maximum input voltage | Balanced, Unbalanced input : 6.0 v |
| AD Maximum Input Voltage (1 kHz, 0.005% Distortion) | MM(30dB/36dB) input:300mV/150mV MC(62dB/68dB) input:7.5mV/3.75mV |
| Minimum load impedance | Balanced, Unbalanced output : 600 Ω Rec : 10k Ω |
| Gain (gain switch 18 dB position) | Balanced, Unbalanced input → Balanced, Unbalanced output : 18 dB Unbalanced input → Rec output : 0 dB AD MM (30/36dB) input → Balanced, Unbalanced output : 48/54dB AD MM (30/36dB) input → Rec output : 30/36dB AD MC (60/66dB) input → Balanced, Unbalanced output : 80/86dB AD MC (60/66dB) input → Rec output : 62/68dB * Gain switch is switchable to 12/18/24dB |
| Compensator | 1:+3dB(100Hz) 2 : + 8 dB (100 Hz), + 6 dB (20 kHz) |
| Subsonic filter | 10 Hz, -18dB/oct. |
| Attenuator | -20dB |
| Pwer | 100 VAC, 50Hz/60Hz |
| Power consumption | 43W |
| Maximum external dimensions | Width 477x Height 156x Depth 412 mm When AD 2800 is added : Depth 414 mm |
| Weight | 21.6kg When adding AD-2800 : 22.5 kg |
| Attachment | Remote Commander RC-200 AC power cord Audio cable with plug (1m) |
| Sold Separately | Phono equalizer unit AD-2800 (¥ 200,000) |