Audio Database

The

Accuphase DP-11
270,000 yen(December, 1989 release)

Description

CD player which introduced the technology cultivated with the highest-class separate type CD player, and was developed.

An 18-bit D/A converter is selected carefully and adopted as a D/A converter.
In order that this converter may improve the engine performance to a limit, it can adjust bit accuracy now, adjusts all the products to the maximum in a product line taking advantage of this advantage, and is pulling out the marginal engine performance.

The cutoff characteristic of an audio filter of removing an unnecessary noise ingredient for a sampling frequency instead of an integral multiple quantity comb is made loose, and it is serving to remove a sound quality prevention factor.
In DP-11, the oversampling digital filter is adopted here 8 times, and the decrease guess for 24.1kHz - 328.7kHz is oppressed on the level of -110dB.
Moreover, pass band Rippl leading to sound quality degradation had become a filter of the highest level which is less than ±0.00005dB and is obtained those days.

The 3rd discrete GIC Butterworth active filter which selected the element carefully was adopted as the audio low PAL filter, and the unnecessary ingredient is cut into it in the loose characteristic of 18 dB/oct.

A digital signal portion and analog circuitry are electrically separated by the "optocoupler."
An optocoupler is a 40 Mbit/sec ultra high-speed type, and full separation is carried out electrically, using this four per channel, and it is performing faithful signal transmission by light.
Moreover, even if it intercepts in a signal course, in order to prevent invading through a power-source part, the power transformer of digital one and analog circuitry is made to become independent, respectively, and is considered as 2 transformer composition, and in order to raise the audio characteristic, the winding wire of the analog transformer is considered as right-and-left independence.
Moreover, in order to prevent the high frequency noise ingredient in which it interferes in electrostatic through space, each circuit was completely shielded on the thick metal plate, and these interference is prevented.

The linear motor mechanism is adopted as the tracking of a laser pickup, it controls by the 8-bit microprocessor developed for exclusive use, and quick song selection for about 1 second is enabled.

A mechanism part is mounted on an aluminum die-casting frame, and prevents resonance, and also carries out floating from a chassis, and is intercepting transfer of vibration. Floating of the disc table was carried out by this, and the vibration from the outside to a mechanism main part is stopped to the minimum.
Moreover, a mechanism main part is supported with a thick metal chassis, and it is thoroughly strengthened to vibration, and has a structure strong against resonance or vibration by having made the whole into strong frame structure.

The noise shaper is carried in order to decrease quantization noise further.
This is a technique of returning an error to the following data in the slight roundness which a digital filter generates, and carrying out noise reduction, and is reducing the noise in an audio frequency band.

A high region is raised at the time of recording, and in order to correspond to CD in which the emphasis which carries out part descent was applied at the time of playback, digital demphasis which changes the characteristic in the state of a digital signal is carried.
This has realized the characteristic of the deflection of ±0.001dB, and less than 1.5 phase difference to the predetermined characteristic.

In the audio stage, the output of a converter is set up and amplifier is made into direct-current servo direct connection system of only a buffer so that there may be no necessity for magnification. This has improved S/N and the distorted characteristic.

The advantage of 18 bits is efficiently employed in volume control, and volume control of a digital system is carried in it.
The level control which there was little sound quality degradation and was excellent thanks to a 2-bit margin also where volume is extracted is made possible.
The variable range can be adjusted with a remote commander by 0--24dB.

The output terminal carries one balanced two RCA phono jacks and XLR type output.
Moreover, the optical fiber and 75-ohm coaxial output based on a digital audio interface which the Accuphase advocated the digital output and were enacted by the EIAJ standard are carried.

If you make it a timer interlocked with and a power source is turned on, the power-on play function which starts a performance automatically is carried.


Internal
Aluminum Attached remote control   RC-4
Microprocessor Digital

Rating of a mode
Form The digital signal playback machine only for CD
Format CD standard format
The number of quantization: 16 bits
Sampling frequency: 44.1kHz
Error correcting system: CIRC
The number of channels: Two channels
Number of rotations: 500-200rpm (CLV)
Performance speed: 1.2 - 1.4 m/s regularity
Reading system Non-contact optical reading (semiconductor laser use)
Laser GaAlAs (it is a terrorism diode to double)
Frequency response 4.0Hz-20000Hz±0.3dB
D/A converter Rudder resistance type 18 bit
Digital filter 8 time oversampling
Noise shaver function
Digital demphasis function
Deflection of ±0.001dB
THD + noise 0.002% (for 20Hz - 20000Hz)
S/N 114dB
Dynamic range 98dB
Channel separation 106dB
An Output power/Output load impedance Balanced: 2.5V/50 ohm (25ohm/25ohm), a balanced XLR type
Unbalanced: 2.5V/50 ohm, a RCA phono jack
Digital level control: For 0 - -24dB, a 1dB step
Digital output format level Format: Digital Audio Interface
Optical:optical power: -21 - -15dBm (EIAJ), and luminescence wavelength:660nm
Coaxial: 0.5 Vp-p/75ohms
The semiconductor used Transistor: 15 pieces
IC: 46 pieces
Diode: 26 pieces
Power source AC100V/117V/220V/240V, 50Hz/60Hz
Power consumption 20W
Dimensions the width 445x height 95(piece -- it includeds) x depth of 325mm
Weight 13.7kg
Attachment: Remote commander RC-4
Remote control system Infrared pulse system
Power source DC 3V
Battery SUM-3 (an IEC name, R6), two pieces
The maximum Dimensions Width 64x height 176x depth of 18mm
Weight 180g (Battery included)