Audio Database

The

NEC AVD-700
125,000yen(around the 1986 time)

Description
 
audio-video surround decoder which carries a 16-bit digital delay.

The 2ch independent 16-bit digital delay which NEC was original and developed is carried, and the property is sharply improved by carrying out AD conversion of the analog signal once, and digitizing and controlling it.
This circuitry consists of a 16-bit linear-line successive-approximation-type analog-to-digital converter, 64 kbitS-RAM, and an IC for a newly developed address control, and is carried two lines by AVD-700. Thereby, the coordination of the delay time for every msec is enabled in the span of 1 - 92msec by the right-and-left independency.

Dolby surround is supported. In AVD-700, delay time can be adjusted according to the magnitude and listening point of the room.

The hole surround functionality by a digital echo is carried.
In AVD-700, in order to obtain the natural presence of a concert hall, the way of using a time delay echo is adopted and a main speaker is the usual stereophonic reproduction,From back or a front surround speaker, what applied the echo to the composite signaling of L+R which is the reflective sound supposing a concert hall is reproduced.
Echo delay time can be adjusted with a digital delay independently at 1msec step, respectively, and the amount of echoes (the amount of echoes) can be adjusted by echo control.

The matrix surround functionality is carried, it is outputting the signal with which a front to rear and others added the negative phase component of opposite ch for 2ch signals which mixed a little signal on either side, and a feeling of surround has been obtained.

It is possible to carry the creation surround functionality, to add one's favorite signal processing, and to reproduce.
In this functionality, other ch signals of a right phase or negative phase are mixable with mixing the signal of other ch(es) of a right phase or negative phase with main speaker L/R, and surround speaker L/R. Furthermore, it is also possible to apply a digital delay and a digital delay echo.

The mix level-control functionality in which sound field can be changed by mixing a little signal of opposite ch with each L/R ch is carried.

The wireless remote control in which a source input, a switching of each surround, a delay time selection, on/off of an echo, and a coordination of a volume are possible is attached.
It is possible to make positions, such as a surround position, delay time, a volume, and Invert SW, memorize to three kinds as a memory functionality with this remote control.

Rear
Attached

Rating of a mode
Form audio-video surround decoder
Surround synopsis Dolby surround
Hole surround
Matrix surround
The CLIE イション surround
<Delay circuit>
Scheme 16-bit linear-line quatization AD/design aidx2ch
A 2ch independent variable (the span of 1 to 92ms, 1second step)
* At the time of a Dolby surround using : 15ms - 30ms
Sampling frequency 44.1kHz
Frequency characteristic Less than [ 10Hz-20kHz±0.5dB ]
Delay time 1ms - 92ms (1ms step variable)
<Digital system>
SN ratio 90dB
Dynamic range 90dB
THD 0.02%
<Analog system>
SN ratio 100dB
THD 0.005%
Video input terminal 1 Vp-p/75 ohms, five lines
Video output-terminal 1 Vp-p/75 ohms, four lines
Audio input terminal 150mV / 47kohm, ten line x2ch
Audio output-terminal out1 and 2:1V/1kohm, 2ch
selector out: 150mV / 1kohm, one line x2ch
Center ch output-terminal 1V/150 ohm, two lines
<Others>
Power consumption 33W
Dimensions The width 430x height 80x depth of 340mm
The width 430x height 90x depth of 361mm (maxima)
Weight 7.3kg
Adjunct Wireless remote control AR-700