Description
Akai GX 400D PRO reel-to-reel tape recorder. Classic Vintage. Exclusive version. Fully revitalized.
Akai was founded by Masukichi Akai and his son, Saburo Akai in 1929 in Tokyo. The word “Akai” in Japanese means “red”, which of course found a reference in the color of the brand’s logo. In the 1940s, the company produced music and audio equipment. The expanding range of the company included originally reel-to-reel tape recorders, cassette recorder, audio amplifiers, video cassette recorder and speakers, followed by CD, DVD and mp3 players. Some of the products were sold in the United States under the brand of Roberts, A & D in Japan and Tensai and Transonic Strato in Western Europe. At the end of the 1960s, Akai and Tandberg introduced an innovative way of recording sound that allowed recording a wider range of high frequencies. In 1984, a new branch of the company called Akai Professional was created, producing electronic musical instruments. However, in the 90s, the company reduced its range of Hi-Fi equipment. At the end of 2004, Akai Corporation was taken over by Grande Group and Akai Professional by Numark Industries due to bankruptcy.
AKAI GX-400D is a 2-track tape recorder with a 4-track playback option, launched in 1973 as the highest model in its series. The highest quality hardened glass and crystal were used to build the core of the GX head, which translates into very high electromagnetic conversion efficiency and excellent high-frequency properties. This solution enables exceptional abrasion resistance and a much better signal-to-noise ratio. Additionally, this model has a built-in dual drive mechanism with a newly designed AC servo motor. Thanks to this we obtain accurate rotational speed and torque regardless of fluctuations in external load conditions. Also, belt speed deviation is reduced thanks to the use of an advanced electronic control circuit. A direct function change system was also used. As a result, the buttons are highly sensitive and operate smoothly.
The GX-400D features an amplifier section consisting of high-quality circuitry, including a constant voltage circuit and a first-stage equalizer. The microphone amplifier has four independent circuits built-in. Each has sufficient gain and a dynamic margin greater than 55 dB, as well as a step-type potentiometer for recording with two-channel mixing using four microphones. In addition, thanks to the use of a detection foil, automatic forwarding from playback and playback from rewinding mode are possible.
The new, enlarged enclosure has been completely revitalized, made of rosewood, finished with Chinese oil produced from natural oils and natural turpentine-based beeswax. All plastic elements were cleaned and painted using the automotive wet painting technique. Black varnish was used and secured with a colourless satin one.
The device has been fully reviewed and serviced.
Unique world-class specialist mechanics and electronics service (80 man-hours):
– replacement of 30 transistors in the audio track with low-noise transistors – noise in the playback track reduced by 5.5 dB
– calibration of the playback and recording track using special test tapes, oscilloscope and audio analyser
– comprehensive device cleaning using specialist cleaning agents
– checking of electrolytic capacitors
– repair of reel motors with the removal of axial play and replacement of lubricants and oils
– cleaning and repair of potentiometers and switches
– replacement of lubricants in the mechanical elements of the tape recorder
– replacement of capstan bearings
– installation of new slide bearings, polishing of the shafts
– repair of micro switches responsible for mechanical control
– repair of vibration dampers – glass-graphite
– polishing of the bridge and head housings
– cleaning of deflection indicators
– repair and maintenance of the counter
– replacement of belts
– replacement of 8 relays
– cleaning and installation of new rubber dampers for electromagnets
– straightening of plate shafts
– improving the aesthetics of the plates
– cleaning the circuit boards in an ultrasonic cleaner
– adjustment of the clutches
– new aluminium feet
Included in the set:
– two BASF aluminum reels
– AKAI nab adapters
– aluminum nab adapters
– MAXELL UD tape
– RC 19 remote control
– TA 270 timer control adaptor
Collector’s item. The device is in perfect condition!
Technical data:
– 2-track with 4-track playback option, stereo / mono
– heads – 2 x recording, 2 x playback, erasing
– motor – 2 x drive, 1 x capstan
– spool size – 10.5 inches
– tape speeds – 3 3/4 – 7 1/2 – 15 ips (small studio)
– noise and flutter – 0.07% (15 ips)
– frequency response – 20 Hz – 30 kHz (15 ips)
– signal-to-noise ratio – 54 dB
– total harmonic distortion – 1%
– input – 70 mV (line), 15 mV (DIN), 0.6 mV (microphone)
– output – 0.775 V (line)
– dimensions – 61.5 cm (height), 48 cm (width), 20 cm
– weight – 35 kg
– Japanese production from 1974