Nakamichi SR-40

Commentary

FM/AM stereo receiver equipped with STASIS circuit.

STASIS circuit is mounted in the amplifier section.
This circuit can transmit the input signal to the speaker without any distortion by pure class A operation, and controls the speaker by providing a large class AB current supply capability in the current amplifier stage.
In the preamplifier section, the input stages of the equalizer amplifier and the line amplifier are differential inputs, and the sy feed section of the line amplifier is a fully discrete configuration to ensure pure signal transmission.

To prevent interference between internal circuits, the video amplifier, tuner, and display parts are carefully laid out so as not to adversely affect the audio circuit.

The power supply uses a multi-regulated power supply that separates the power supply for each amplifier / stage, and an isolated ground system that eliminates interference from the ground line.

The tuner section can switch between Wide and Narrow two stages of the IF band.
In addition, AM and FM can be stored in memory for 10 stations at random. The contents of the memory are retained for about 5 years even when the power supply is removed by lithium battery.

A 70 μ m thick OFC (oxygen-free copper) pattern is applied to the audio circuit board, and OFC wire is used on the front of the wiring material.
In addition, we are pursuing an anti-vibration structure by attaching damping material to the chassis and volume by extruding aluminum, and filling the volume knob with brass.

It has an input terminal for video equipment.

It is equipped with a variable loudness control function a natural loudness effect.
In contrast to the conventional method of emphasizing low and high frequencies at low volume, this method provides a loudness effect by reducing the overall volume while narrowing down the level of the middle range.

Processor loop input / output terminal is mounted.

The Phono input has both MC and MM positions, and the MC gain can be switched in two stages.

The volume can be adjusted from a wireless remote control, so it uses a motor drive system.

It is equipped with a subsonic filter using a simulated inductor method in which the music signal does not pass through the operational amplifier.

Equipped with an on/off tone control.

Equipped with audio mute which can reduce the output level to 1/10.

One touch switching between auto-seek and manual tuning is possible.

Equipped with a detachable AM loop antenna.

It is equipped with a protection circuit that protects the circuit and speakers from DC component leakage and abnormal heat generation.

Includes a wireless remote control that enables you to turn the power on/off, adjust the volume, tune the tuner, call up program memory, and mute audio.

Model Rating

Type	Stereo receiver
Amplifier Unit
Rated output	75W + 75W (6 Ω) 60W + 60W (8 Ω)
Total harmonic distortion factor	0.1% or Less (8 Ω, Rated Output, 20 Hz to 20 kHz)
Frequency characteristic	5 Hz ~ 75 kHz + 0 -3dB
S/N ratio (IHF A-WTD, SP out, input short)	Phono MC : 73 dB or higher (gain 32 dB, 1W) 72 dB or more (gain 24 dB, 1W) Phono MM : 80 dB or more (1W) CD, vide, tape : 105 dB or more (rated output)
Input Sensitivity / Impedance	Phono MC : 60 μ V/100 Ω (gain 32 dB) 160 μ V/100 Ω (gain 24 dB) Phono MM : 2.5mV/47k Ω CD, video, tape : 200mV/20k Ω
FM Tuner Section
Practical sensitivity	11dBf/0.97 μ V (75 Ω)
S/N ratio (85 dBf input)	Mono : 85 dB or more Stereo : 80 dB or more
Frequency characteristic	20 Hz to 15 kHz ± 1 dB
Harmonic distortion factor (1 kHz, wide)	Mono : not more than 0.05% Stereo : not more than 0.07%
Effective selectivity	Wide : 55 dB or more (± 400 kHz) Narrow : 70 dB or more (± 300 kHz)
Stereo separation	Wide : 50 dB or more (1 kHz)
<General>
Pwer	100 V, 50Hz/60Hz
Power consumption	380W maximum
External dimensions	Width 430x Height 100x Depth 370 mm
Weight	Approximately 10 kg
Attachment	Wireless Remote Control