Technics SA-R40
¥ 138,000 (released in 1981)
Commentary
An air check amplifier that integrates an FM/AM tuner, cassette deck and pre-main amplifier.
An electronically controlled DC motor is used to drive the capstan in the travel mechanism of the cassette deck, an IC is used in the travel control system, and a DC motor is used to drive the reel. Fluctuations in tape tension during recording and playback are controlled to a minimum by controlling the reel motor current with an electronic circuit.
The recording / reproducing head uses an all-Sendust head with high saturation magnetic flux density and low high-frequency loss. In addition to the Sendust head with excellent abrasion resistance, a Sendust mask is used on the tape contact surface other than the core to prevent uneven wear. The head shape is a hyperbolic shape with excellent contact with the tape to prevent disturbance of frequency characteristics.
The erasing head uses a 3-gap ferrite head with high erasing efficiency to cope with the high coercive force of metal tapes.
It is equipped with an automatic music selection mechanism (TPS) that can start up to 9 songs in front and back. It can set the number of songs up to the desired number of songs and detect the number of songs displayed on the address counter by the ff/rew operation, and start up the desired number of songs.
In addition, it is equipped with Rec Mute which can make voice-cut and unrecorded parts.
Equipped with an FL display that displays peak values in two colors of less than 0 dB and more than 0 dB.
The peak value is clearly displayed with an attack time of 120 μ sec. and a recovery time of 270 msec.
Equipped with Dolby NR circuit and recording / playback timer standby.
The tuner section is equipped with a quartz synthesizer.
The front-end uses a high-Q varicap and junction FET to improve the IM interference rejection capability, and the IF stage uses a ceramic filter with excellent group delay characteristics to obtain sharp selectivity characteristics.
The reference frequency for locking the local oscillation frequency of the quartz synthesizer tuner is set to 25 kHz outside the audio band to prevent leakage into the audio band and improve sound quality. In addition, the synthesizer section employs a unique swallow in counter method and a special frequency division method that uses a prescaler controller to control 1/16 and 1/17 minute periods prevent spurious interference from occurring in the broadcast band.
Presets for 7 FM/AM stations are available. In addition, an auto-scan tuning function is installed. If you turn on the auto-scan button and press one push of the up/down key, you can tune to the nearest station. If you turn off auto-scan, manual tuning is also available.
Equipped with 5 LED signal strength indicator to indicate electric field strength.
Equipped with a last one memory function that retains the last receiving station until the next power is turned on.
The amplifier section uses a new class A amplifier that combines the quality of class A operation with the high efficiency of class B operation.
In this method, a constant bias current is supplied in synchronization with the rest cycle to the output transistor which normally goes into complete rest alternately in order to obtain high efficiency in class B and class AB by a synchronous bias circuit, and switching distortion caused by the rest is eliminated by keeping the output stage active at all times.
In addition, since the signal path and bias current path are independent, the output stage always keeps an appropriate operating point. Together with the function of the high-speed response diode, crossover distortion is eliminated and the sound quality of class A operation is obtained.
In addition, a new study of the NFB theory was added, and a linear feedback circuit unique to Technics with infinite gain in the NF loop is mounted, and the strain characteristic in the range of audibility is greatly improved.
It uses a unique concentrated power block that reduces degradation of high-frequency characteristics due to electromagnetic radiation.
The phono equalizer is an ICL circuit without the influence of the input capacitor. It consists of an IC with a differential amplifier circuit using a low-noise FET, an input stage using a current mirror load, and an output stage using a SEPP circuit.
It is also equipped with a subsonic filter to cut out unwanted low frequencies.
The tone control uses a center defeat type in which the element comes off at the midpoint.
Equipped with microphone mixing mechanism, microphone mixing with each source is possible.
External unit connection terminal is mounted on the rear panel, and external equipment such as frequency equalizer can be connected.
The Rec out terminal is mounted.
Equipped with a relay type protection circuit for muting.
By using the separately sold remote control box (RP-9645), the set deck can be operated from a remote location.
Model Rating
| Type | Air check amplifier |
| Amplifier Unit | |
| Effective output (both channel drive, 8 Ω) | 40W + 40W (20 Hz to 20 kHz, 0.009%) 40W + 40W (1 kHz, 0.007%) |
| Total harmonic distortion factor | 0.007% (20 Hz to 20 kHz -3dB) |
| Damping factor (8 Ω) | 30 |
| Load impedance | 6 Ω ~ 16 Ω |
| Input Sensitivity / Impedance | Phono : 2.5mV/47k Ω Aux/TV : 150mV/68k Ω Mic : 2.0mV/22k Ω |
| Phono maximum allowable input (1 kHz, RMS) | 150mV |
| Signal-to-noise ratio | Phono:80dB Aux/TV:80dB Mic:70dB |
| Frequency characteristic | Phono : 20 Hz to 20 kHz ± 0.5 dB Aux/TV : 5 hz to 45 khz + 0 to 3 db Mic : 20 Hz to 25 kHz + 0 -3dB |
| Tone control | Bass : 50 Hz, ± 10 dB Treble : 20 kHz, ± 10 dB |
| Loudness control (Volume -30dB) | 50Hz:+9dB |
| Output level | Rec out:150mV |
| External unit connection terminal | In : 150mV/27k Ω Out : 150mV/1k Ω |
| FM Tuner Section | |
| Receiving frequency | 76.1 mhz to 89.9 mhz |
| Practical Sensitivity (IHF, 75 Ω) | 10.3 dBf, 0.9 μ V |
| S/N50dB sensitivity (75 Ω) | Mono : 18.5 dBf, 2.3 μ V |
| Total harmonic distortion factor | mono:0.15% |
| Signal-to-noise ratio | mono:76dB |
| Frequency characteristic | 20 Hz ~ 15 kHz + 0.5 -1.5 dB |
| Effective selectivity | 60dB |
| Capture ratio | 1.0dB |
| Image Interference Ratio (83 mhz) | 55dB |
| Spurious interference ratio (83 MHz) | 80dB |
| AM suppression ratio | 55dB |
| Stereo separation | 45dB |
| Leak Carrier (19 khz, 38 khz) | -35dB |
| Antenna terminal | 75 Ω (Unbalanced Type) |
| <AM Tuner Section> | |
| Receiving frequency | 522 kHz to 1,611 kHz |
| Sensitivity | 25 μ V, 250 μ V/m |
| Selectivity | 45dB |
| Image interference ratio (999 kHz) | 55dB |
| IF interference ratio (999 kHz) | 45dB |
| Cassette Deck Part | |
| Truck type | 4-track 2-channel stereo |
| Head Used | Recording : All Sendust Head Erasing : 3-gap ferrite |
| Motor used | For Capstan : Electronically Controlled DC Motor For Reel : DC Motor |
| Recording bias system | AC bias system Bias frequency : 85 kHz |
| Erasing method | AC erasing method |
| Tape speed | 4.8cm/sec. |
| Frequency characteristic | Normal-20 Hz to 18 kHz CrO2, XAII : 20 Hz to 19 kHz Metal : 20 Hz to 20 kHz |
| Signal-to-noise ratio | 58 dB (XAII, peak level) 68 dB (Dolby NR in, 5 kHz or higher) |
| Wow and flutter | 0.045%(WRMS) |
| <General> | |
| Pwer | 100 VAC, 50/60Hz |
| Power consumption | 115W |
| External dimensions | Width 430x Height 119x Depth 394 mm |
| Weight | 12.0kg |
| Sold Separately | Wired Remote Controller RP-9645 (¥ 6,000) |