Category:Mid High Fidelity (most Japanese recorders fall into this category)
Country of Manufacture:Japan
Release dates: -
Speeds: 3 3/4, 7 1/2
Max Reel Size("): 7"
Number of heads: 2
Dimension: 358 x 360 x 248mm (14 x 14.1 x 9.8")
Head Composition: Permalloy
Head Configuration: Stereo
# Motors: 3
Frequency Response:( 3dB): 7½ ips: Using low noise tape: 30Hz - 21kHz (30Hz - 18kHz regular)
Wow and Flutter:less than 0.14% at 7½ ips, less than 0.18% at 3¾ ips
Signal-to-Noise Ratio:50 dB at maximum tone control
Sound quality rating:6 / 10
Long-term reliability rating: 7 / 10
Weight: 13.2 Kg (29 lbs)
New in 1973, the 1721 was a deluxe, self-contained two-speed quarter-track stereo tape recorder with all-silicon transistor circuitry and twin in-built 5 x 7″ speakers.
The recorder was available in either a wooden case (1721W) or leather-finish on wood case (1721L) and one could choose either a black (pictured) or silver finish.
Still sporting the now almost 12 year-old Akai twin-lever transport operation system, this machine featured two large VU meters, a three digit tape counter, front panel microphone jacks, low noise tape selector switch
plus a magnetic phono cartridge input.
Half track versions were also available (W-H and L-H) and this version only had a single channel power amplifier and one internal speaker.
Hum and noise: less than 10mV at minimum tone control / Crosstalk: better than 45 dB (stereo), 60dB (mono) / Distortion: less than 2% (1,000 Hz “0” VU) / Bias frequency: 63 kHz 8% / Erase ratio: better than 70 dB / Semi-conductors: 4 x 2SC458 LG, 4 x 2SC711, 2 x 2SC871, 2 x 2SC968, 4 x 2SC1013 Diodes: 2 x 1N34A, 2 x 10DC-1 / Rewind speed: 80 seconds for 1,200 ft / Audio output power: 4 watts per channel / Inputs: Microphone: 0.5 mV impedance 100 Kohms Line: 150 mV impedance 330 Kohm DIN: 7 mV / Outputs: Line: 1.228V (+4 dB using a 25Hz test tone “0” VU) Din: 1V Headphones: 100 mV at 8 ohms Speaker outputs: 10 watts music power, 6 watts continuous at 8 ohms / Speaker(s): 2 built-in 7 x 5 ” oval speakers