The Aurex (a Toshiba brand name for Japan) PC-4280 was a compact, portable cassette recorder introduced in 1977. The biggest feature of the PC-4280 is the use of a 3-Head System, a rare feature for a portable deck. This system consists of 3 independent (discrete) heads mounted on a rigid zinc die-cast head block. There is a hyperbolic AS (all-sendust) 1 micron playback head, a ferrite 5 micron recording head and a double gap ferrite erase head which doubles as a tape tensioner. The mechanism is using a high-precision 38 pulse FG servo controlled belt drive mechanism with mechanical tape control. A built-in 6kHz oscillator can be used for record head Azimuth adjustment and a 400Hz oscillator can be used for recording sensitivity adjustment. Settings can be visualized on the VU meters. The deck can be powered within a voltage range of 7-16 V with the help of a built-in DC-DC converter. A clip-on battery box and external 100V AC adapter were also available. Accesories included a shoulder strap and a dust cover that allowed activating the pause function with the lid closed. This portable recorder can be further expanded with the use of the MX-2480 6 channel mixer (microphones and line), the SS-4280W active 10W loudspeaker system or the MA-15 external "adres" noise reduction unit. Technical data: Frequency response: 20-18.000 Hz chrome | Signal to noise: 60dB | Wow and flutter: 0.07% (RMS) | Dimensions: 300x135x85 mm | Weight: 3.4 kg (without batteries)