Audio Database


Accuphase DC-330
880,000 yen(November, 1999 release)


The digital preamplifier which aimed at upgrade for the engine performance which is renewed in the design which used direct-current-300 as the base and took operativity into consideration, concentrates the newest digital technology, and can be adapted for the new generation digital format of SACD etc. in all the circuits.

Into all the option slots of direct-current-330, 2.8224MHz of bit stream outputs of SACD/1 bit, 192kHz/24 bit, etc. can input the digital signal of a new generation format. An ultra Jitter free PLL circuit extracts a highly precise standard signal (master clock) without pulse transmission distortion or a Jitter from the inputted signal.
The incoming signal changed into the format inside apparatus goes into ultra high-speed DSP (Digital Signal Processor), and carries out digital operation processing of the tone control functions, such as tone control, a Compensation, a monophonic, and a phase change.
Between the D/A converters which influence sound quality, the ultra high-speed isorated digital coupler has separated electrically completely the digital part which consisted of DSP etc., and the analog part after a D/A converter. Then, digital volume, balance, and Attenuator processing were performed and it has changed into the analog signal by the newly developed MDS system D/A converter.
The signal changed into the analog cuts an unnecessary digital ingredient with the 3rd linear phase type analog filter excellent in the phase characteristic, and is outputting it by balance / two imbalanced lines.

The newly developed MDS (multiple 冱igma) system D/A converter that aimed at the extensive engine-performance improvement by carrying out parallel connection of two or more 冱igma type D/A converters is carried in the D/A conversion part.
冱igma type D/A converter is a D/A conversion system which uses oversampling and noise shaping, develops the amplitude information on the inputted digital signal in the direction of a time-axis, and acquires conversion accuracy. In MDS, two or more these is arranged in parallel, altogether, an input and the output of each converter are added to each converter, and the same digital signal is made it with the whole output.
In direct-current-330, in order to carry out parallel operation of the six 冱igma type D/A converters, as compared with the case of converter 1 circuit, the whole engine performance is improving to 2.45 (=root6) time.
The feature of a MDS system can be reducing the noise of the minute level which is a point which can raise the engine performance, divides into the output signal which was difficult for dissolution by all the frequency and all the signal levels with ま, and is attached to it by the conventional 冱igma type D/A converter with them regardless of signal frequency or a signal level.

The original volume control which made analog a feeling of operation possible is adopted as volume.
The disc in which the slit was cut radiately is attached to the shaft of a large-sized knob, when a disc passes a phase detector, a pulse is generated, this pulse is inputted into a microcomputer, and volume is adjusted.
The check of 1 of volume is possible with lighting of LED arranged on the display of a level numerical value, and the perimeter of a knob.

The 3rd linear phase type filter excellent in the phase characteristic is adopted as the analog filter for removing the image noise of a super-high region.
This filter circuit is suppressing rotation of the phase in a pass band to the minimum by optimization of cutoff frequency, and using the element selected carefully, and is aiming at the sound quality improvement.

The printed circuit board by a Teflon board (woven glass fabric fluoro-resin) is adopted as a D/A converter part.
Teflon has the features, like heat resistance and the high frequency characteristic with very little (low loss) leak current with a low (high propagation velocity) dielectric constant are excellent. By using this Teflon base for an audio circuit, purer transmission of the signal was attained and the signal to noise ratio on Hearing impression is improved further.
Moreover, in direct-current-330, a golden plate is further given to a Copper foil side and improvement in sound quality is aimed at.

The master clock from which it is made to synchronize with a DAI signal, and even operation serves as a standard of a system by a PLL (Phase Locked Loop) circuit in a D/A converter for a る reason is extracted.
Here the ultra Jitter free PLL circuit is adopted, and the crystal oscillator is adopted as a preamble signal (marker in which head of LR signal is shown) detector circuit, and VCO (Voltage Controlled Oscillator). The master clock extracted in this circuit is not influenced by a Jitter or pulse transmission distortion.

In order to separate a digital part and an analog part completely, the high-speed isorated digital coupler with the throughput of 80Mbps is adopted. It was transmitted to the analog part, without accompanying a digital signal by noise by an ultra high-speed transmission characteristic, and has contributed to the sound quality improvement.

The tone control and the Compensation by ultra high-speed DSP are carried.
Since it is possible to change only frequency, without changing circuit impedance in the digital processing by DSP, the acoustic field control which does not have signal degradation, either and does not have sound quality change is possible.

A turn of an input selector will carry out the character display of the contact button of apparatus to a display. The function in which the input terminal can be changed into a favorite name is carried.
It is also possible to change into SACD and DVD which have been registered beforehand, CD, MD, etc., or to make an original name combining eight characters out of 96 kinds of a character and signs.

The analog output consists of full balance circuits by which floating was carried out from the ground.
Moreover, the output terminal carries each the XLR type connector for balance, and two RCA type connectors for imbalanced.

All of the input and recording output of direct-current-330 correspond by the option board. For this reason, the option slot with the port of the ADB2 interface standard corresponding to the new generation format of SACD etc. is carried.
It is possible to input the SACD digital output of DP-100 or DP-85 by extending a HS-Link input board and connecting by a HS-Link cable.
The digital input/output has equipped standardly the option board (DIO-OC1) with an optic and the same axle. Furthermore, BNC, HPC optical (ST), and a HPC balance input are possible as an extension option.
The analog line-in board (A.I. Artificial Intelligence2-U1) with the high precision 冱igma A/D converter corresponding to 96kHz/24bit is equipped standardly.
The "EXT DSP option board" extension slot which can connect digital voi synge equalizer DG-28/DG-38 is equipped.
Digital channel divider DF-35 was connected and the Outputs option board extension slot in which digital volume control is possible is equipped.

Rear Option
An Ultra
Ultra D/A High-speed
Volume The DAI,

Rating of a mode
Form Digital preamplifier
Entry format
(It is based on EIAJ CP-1201)
The number of quantization: 16 bits - a 24-bit straight line
Sampling frequency: 32kHz, 44.1kHz, 48kHz, 88.2kHz, 96kHz
(16-each 24 bits 2ch PCM)

* Correspond to an option board.
176.4kHz, 192kHz (24 bits each 2ch PCM)
2.8224MHz(1bit 2ch DSD)
Digital input format level
(EIAJ CP-1201)
Format: Digital Audio Interface
Optical: Optical input -27dBm - -15dBm
Coaxial: 0.5 Vp-p/75ohms
(It is based on option board correspondence)
Digital output format level
(EIAJ CP-1201)
Format: Digital Audio Interface
Optical: Optical power -21dBm - -15dBm, luminescence wavelength 660nm
Coaxial: 0.5 Vp-p/75ohms
(It is based on option board correspondence)
Frequency response 0.5Hz-50kHz+0 -3 dB
D/A converter 24bit MDS systems
THD 0.0006% (20Hz - 20kHz)
S/N 120dB
Dynamic range 112dB (a 24-bit input, LPF:off)
Channel セパレーション 108dB (20Hz - 20kHz)
An Output voltage/impedance Balanced: 5V/50 ohm, a balanced XLR type
Unbalanced: 5V/50 ohm, a RCA phono jack
Volume control Speed perception rotary system
Linear mode: -infinity, 0.5-99.5 (0.5 step), Max
dB mode: -infinity, -94.0dB-+12.0dB
Balance control (DSP) A difference on either side: -infinity, -4-0dB (1dB step)
Tone control (DSP) Bass(315Hz): ±5dB (50Hz), a 1dB step
Treble(3.15kHz): ±5dB (20kHz), a 1dB step
Compensation (DSP) 1:+3dB(100Hz)
3: +6dB (100Hz), +3dB (20kHz)
5: +9dB (100Hz), +6dB (20kHz)
Attenuator (DSP) -20dB
Power source AC100V, 50Hz/60Hz
Power consumption 25W
The maximum Dimensions Width 475x height 150x depth of 412mm
Weight 20.2kg
Attachment Line-in board A.I. Artificial Intelligence2-U1
Digital-input/output board DIO-OC1
Remote commander RC-24
AC power cord (2m)
An audio cable with a plug (1m)
75-ohm coaxial cable (DL-15)
Option: Option board
Digital relations
The HPC core キシャル input board DI-BNC1 (30,000yen)
A 75-ohm coaxial cable with a BNC connector is connectable.
Sampling frequency: 96kHz/24 bits
Digital input: 0.5 Vp-p/75ohms

* 1 slot use

The Digital-input/output board DIO-OC1 (40,000yen)
The option board which carries the input-and-output terminal of the same axle and an optical fiber.
Sampling frequency: 96kHz/24 bits

* Preinstall in the slot of Option7.
* 1 slot use
With no picture HPC optical input-and-output board DIO-ST1 (50,000yen)
The option board which carries optical ST type link input and output connectors.
Sampling frequency: 96kHz/24 bits

* 1 slot use

The AES/EBU input-and-output board DIO-PRO1 (60,000yen)
The option board which carries the input-and-output XLR connector corresponding to AES/EBU (business-use digital standard).
Sampling frequency Input: 96kHz/24 bits
Output: 48kHz/24 bits

* 2 slot use
The HS-Link input board DI2-HS1 (100,000yen)
The input board which transmits a digital signal with a HS-Link interface.
The SACD/CD digital signal of DP-100 or DP-85 can be inputted by a HS-Link cable.

* 2 slot use
The HS-Link output board DO2-HS1 (80,000yen)
By extending this board, the digital data transmission of the digital signal
of DP-100 or DP-85 becomes possible to DF-35 via direct-current-330.
It connects by a HS-Link cable.

* 1 slot use
The Broadband digital-input/output board for DG-28 DIO2-DG1 (100,000yen)
The digital signal exceeding 48kHz of sampling frequencies,
such as SACD, is inputted into DG-28, and it comes to be able to carry out acoustic field
compensation by extending into the EXT DSP slot of direct-current-330 and connecting with DG-28.
It connects by a 75-ohm coaxial digital cable.

* 2 slot use

Analog relations
An analog input is changed into a digital signal by the A/D converter in a board.
An output is changed into an analog signal by the D/A converter in a board.
With no picture Line-in board A.I. Artificial Intelligence2-U1 (60,000yen)
The high level (analog signal) input terminal for imbalanced connection is carried.
Sampling frequency: A 48/96kHz change is possible.

* Preinstall in the slot of Option8.
* 1 slot use

With no picture Balance input board A.I. Artificial Intelligence2-B1 (70,000yen)
The high level (analog signal) input terminal for balance connection is carried.
Sampling frequency: A 48/96kHz change is possible.

* 2 slot use

With no picture Line-out board AO2-U1 (80,000yen)
The output terminal for analog recording by imbalanced connection.
When it extends to direct-current-330, it becomes correspondence to 96kHz of sampling frequencies.
Moreover, the signal inputted by HS-Link is not outputted from AO2-U1.

* 2 slot use

With no picture Balance output board AO2-B1 (80,000yen)
The output terminal for analog recording by balance connection.
When it extends to direct-current-330, it becomes correspondence to 96kHz of sampling frequencies.
Moreover, the signal inputted by HS-Link is not outputted from AO2-B1.

* 2 slot use

The Analog disc input board A.I. Artificial Intelligence-AD1 (100,000yen)
The high gain equalizer for analog record playback, and the carried option board.
MM/MC correspondence (gain: MM30dB, MC60dB)
Sampling frequency: 48kHz

* 2 slot use
The Line input-and-output board AIO-U1 (60,000yen)
The analog recording and the playback terminal for imbalanced connection.
Sampling frequency: 48kHz

* 1 slot use