Audio Database


Technics SU-V90D 89,800yen(around the 1987 time)

The Integrated Amplifier which carries a digital analog converter.

4DACs and 18-bit conversion system are adopted as a D-A-conversion part.
In 4DACs and 18-bit conversion system, two digital analog converters which carry out the independent process of + component and - component of an input signal are carried in each channel of L/R, and it is considered as 4DAC conversion system which uses a total of four digital analog converters. In this circuitry, first, by newly developed 4DAC processor LSI, the signal of + and - is distinguished out of the inputted digital signal, two digital analog converters are switched and the high-speed treatment of these signals is carried out. The D-A conversion which zero cross distortion does not generate theoretically by this is realized.
Moreover, adoption of 4DAC processor LSI etc. has realized an 18-bit operation of a digital analog converter in the mean-value music level not more than -12dB. This has acquired analog signal waveform regeneration capacity with more faithful adoption and interval of the digital filter of a 4 time oversampling 18bit scheme.

With the automatic switching scheme, the sampling frequency supports three kinds, 32kHz, 44.1kHz, and 48kHz, and supports a compact disk player, DAT, and a BS tuner.

The digital input carries two lines, light and a coaxial.

The classAA amplifier of a VC-4 amplifier (Voltage Current 4 amplifier system) stream composition is carried in the power amplifier part.
In this circuitry, in each ch of L/R, voltage control amplifier is released from the current supply source, and voltage control very faithful to an input signal is realized by making separate amplifier take charge of voltage control and an electric-current drive. Moreover, electric-current drive amplifier has acquired sufficient current-supply-source capacity for a speaker drive.

The power transformer with which the high-density efficient technology by an OFC line full sort coil method was used is carried in the power-source part.
Moreover, the newly developed high speed EX electrolytic capacitor is adopted as the electrolytic capacitor for power sources. By application of biotechnology, this capacitor is improving the purity of the electrolytic solution double or more figures, and has also canceled the slight distortion by the impurity adhering to an electrode.

loading s The power amplifier direct functionality in which compact-disk direct functionality was developed further is.
having inputted directly the power amplifier direct input signal and the built-in digital-analog-converter output signal into power amplifier only through a classAA buffer and a power amplifier input volume in this functionality -- high -- the purity amplification is enabled. Having adopted the P.C.L. low-impedance volume as the power amplifier input volume and an interval have realized an SN ratio modification effect of about 10dB.

The performance analysis and audition which were put into practice also among the selection of the audio peculiar part are carrying out the careful selection using of high purity OCC and the OFC material at an in-use cage, an internal wiring, or the lead wire of each part.

In order to reduce the tone-quality failure by oscillation of amplifier, measures against vibration proof, such as a large-sized metals insulator, are taken.

In order to prevent a digital circuit, a phone equalizer circuitry, and a power amplifier circuitry interfering mutually, each block is shielded severely. Furthermore, thorough exclusion of the tone-quality failure by the interference between the sources is carried out with adoption of the active servo power supply which eliminates the interference which leads a power source.

The rear panel of SU-V 90D equipped with the input terminal with abundant includeds for the optical link

The internal structure of SU-V 90D

(Above) OCC cross-section system
(Below) Conventional material cross-section system

classAA conceptual diagram

The block diagram of a power amplifier direct

(Left) High speed capacitor
(Right) The conventional electrolytic capacitor

Rating of a mode
Form Integrated amplifier
Effective output (20Hz - 20kHz) 120W+120W (6 ohms, 0.005%)
THD 0.002% (Output-power-3dB, 20Hz - 20kHz)
Frequency characteristic 20Hz-20kHz+0 -0.2 dB
0.8Hz-150kHz+0 -3 dB
SN ratio 115dB (at the time of IHF'66 and Power Amp Direct)
Dumping factor 80 (8ohms)
Load impedance main or remote: 6ohms - 16ohms
Input sensitivity/impedance Phono man month: 2.5mV / 47kohm
Phono MC: 170 microvolts/220 ohms
tuner, compact disk, aux, tape:150mV /, 22kohm
Phono SN ratio man month: 88dB (2.5mV input)
MC: 72dB (250-microvolt input)
Tone control Bass: ±10dB (50Hz)
Treble: ±10dB (20kHz)
Loudness control (VR-30dB) +9dB(50Hz)
Power source AC100V, 50Hz/60Hz
Power consumption 220W
Dimensions Width 478x height 158.4x depth of 397mm
Weight 14.7kg