Audio Database

The

Nakamichi SR-40
148,000yen(around the 1987 time)

Description
 
FM / AM-stereo receiver which carries a STASIS circuitry.

The STASIS circuitry is carried in the amplifier part.
This circuitry can transmit an input signal to a speaker by non-distortion as a matter of fact by pure Class-A operation, and also gives the large-current supply capacity of AB class to the current amplification stage, and is controlling the speaker.
Moreover, the preamplifier part made the difference input the input stage of an equalizer amplifier and line amplifier, and also is aiming at thoroughness of pure signal transmission, such as making sy copy power part of line amplifier a perfect discrete stream composition.

In order to prevent the cross interferencee between internal circuitry, each part of video-system amplifier, a tuner, and a display device is carefully arranged with not having an ill effect on an audio circuitry.

The multi-regurated power supply which separated the powering for every amplifier / stage, and the isorated grand scheme which eliminated the interference involving an earth line are used for a power-source part.

The 2 steps of Wide/Narrow change of IF band is possible for a tuner part.
Moreover, the ten-game memory of AM and the FM can be carried out at random. The description of memory is held for about five years, also where a power source is extracted with a lithium cell.

The OFC (oxygen free high conductivity copper) pattern of 70micro thickness is pulled to the substrate of an audio part, and front adoption of the OFC line is carried out also at product-line material.
Moreover, dumping material is stuck on the chassis and volume by aluminum extrusion, and the vibration proof structure is investigated, such as filling up the interior of a volume thumb with brass.

The input terminal for video equipments is carried.

The variable loudness control functionality in which the natural loudness effect is acquired is carried.
As for the general scheme which emphasizes low-pass and a high region at the time of a small sound volume, this is giving the loudness effect by narrowing down the level of a mid range conversely, lowering the whole sound volume.

The processor loop input/output terminal is carried.

The Phono input carries both the positions of MC/man month, and a two-step change is possible for MC gain.

Since a volume corresponds also to the coordination from wireless remote control, it has adopted the motor drive scheme.

The music signal carries the Subsonic Filter by the simulated inductor scheme which does not pass along operational amplifier.

The tone control which can be turned on and off is carried.

The audio mute as for which an Output voltage is made to 1/10 is carried.

An auto seek and a manual tuning can be switched by one-touch.

AM loop antenna which can be detached and attached is carried.

The protection circuitry which protects a circuitry and a speaker from a leakage and unusual exothermic of a direct current component is carried.

The wireless remote control in which on/off of a power source, a volume coordination, tuning of a tuner, the call of program memory, and an audio mute are possible is attached.

Rear
Stream-composition

Rating of a mode
Form Stereo receiver
<Amplifier part>
Output power 75W+75W (6ohm)
60W+60W (8ohm)
THD 0.1% or less (8 ohms, an Output power, 20Hz - 20kHz)
Frequency characteristic 5Hz-75kHz+0 -3 dB
S/N ratio (IHF A-WTD, SP out, input short-circuit) Phono MC: 73dB or more (gain 32dB, 1W)
72dB or more (gain 24dB, 1W)
Phono man month: 80dB or more (1W)
compact disk, vide, tape: 105dB or more (Output power)
Input sensitivity/impedance Phono MC: 60 microvolts/100 ohms (gain 32dB)
160 microvolts/100 ohms (gain 24dB)
Phono man month: 2.5mV / 47kohm
compact disk, video, tape:200mV /, 20kohm
<FM tuner part>
Practical speed 11 dBf/0.97 microvolt (75ohm)
S/N ratio (85dBf input) mono: 85dB or more
stereo: 80dB or more
Frequency characteristic 20Hz-15kHz±1dB
THD (1kHz, wide) mono: 0.05% or less
stereo: 0.07% or less
Effective selectivity wide: 55dB or more (±400kHz)
narrow: 70dB or more (±300kHz)
Stereo separation wide: 50dB or more (1kHz)
<Synthesis>
Power source 100V, 50Hz/60Hz
Power consumption 380W (maxima)
Dimensions Width 430x height 100x depth of 370mm
Weight About 10kg
Adjunct Wireless remote control