Audio Database

The

NEC AV-300typeII
89,800yen(around the 1986 time)

Description
 
audio-video surround center which carries a digital delay.

The digital delay is carried and the extensive modification of a property is realized by carrying out the A/D conversion of the analog signal once, and digitizing and controlling it.
A 16-bit linear-line successive-approximation-type analog-to-digital converter, 16 KbitS-RAM, and an IC for an address control are consisted of by this circuitry, and the delay time of 15/20/30msec can be set to it.

As surround mode, the three modes, Dolby surround, hole surround, and matrix surround, are carried.
Dolby surround has acquired the surround intelligence by applying a delicate time delay to the difference signal added to 2usual ch signals (L-R). Moreover, in hole surround, the front speaker is being reproduced from the usual stereophonic reproduction and a back surround speaker, applying an echo to the composite signaling supposing a concert hall of reflective sound (L+R).
In matrix surround, 2ch signals which mixed a little signal on either side are reproduced from a front. From rear , the signal which added the negative phase component of opposite ch conversely is reproduced.

The surround indicator which can check at a glance what has happened to the present surround control status is carried.
It is also possible to turn OFF when unnecessary.

At the time of a hole surround play, it is possible to adjust the amount of echoes of surround according to liking.

the full mute switchpoint is carried and all the sound is stopped at a stretch -- things can be carried out.

4 mode balance volume in which, as for the master volume which can control the volume of all the channels simultaneously, the 2ch/rear 2 ch/R side can control 2ch, and the 2 ch/L side can control a front is carried. Moreover, three kinds of volumes of each channel independent volume are carried.

The synthesizer tick stereo functionality is carried and a monophonic signal can be done in a stereo in false by letting a digital-signal-processing circuitry pass.

The it1 position is carried. (to sake when surround is unnecessary)

The tone control which can adjust a front and each rear tone quality is carried.

The image enhancer which rectifies the outline of an indistinct image and reproduces a clearer image is built in.
The change of a two-step of 3dB and 6dB is possible for the amount of enhancing.

Independent power amplifier is carried 4 ch.
The using as 2ch amplifier is also possible for this amplifier by the BTL interconnection.

The wireless remote control in which the change of each surround, a delay time selection, and a volume coordination of each ch are possible is attached.
With this remote control, a surround position, a volume, delay time, etc. are memorizable to three kinds with a memory functionality.

Attached

Rating of a mode
Form audio-video surround center
<Amplifier part>
Effective output (1kHz, 5%, 6ohm) 50Wx4
100W+100W (at the time of BTL)
THD 0.03% (at the time of 20W output)
SN ratio Main in:100dB
Input unit Voice: Mono-[ three stereos, / two ]
Image: Four lines
Input sensitivity/impedance Voice input: 150mV / 47kohm
Video input: 1 Vp-p/75ohm
<Processor part>
Surround synopsis Dolby surround
Hole surround
Matrix surround
Latency scheme 16-bit linear-line quatization (digital)
Delay time 15, 20, 30msec
<Synthesis>
Power consumption 165W
The maximum Dimensions Width 430x height 110x depth of 340mm
Width 430x height 122x depth of 359mm (maxima)
Weight 9.5kg
Adjunct Wireless remote control AR-301