Country of Manufacture:USA
Release dates:1969 - 1972
Original Price: $$119.9
Speeds: 7 1/2, 3 3/4, 1 7/8
Max Reel Size("): 7
Number of heads: 3
Head Composition: Permalloy
Head Configuration: Stereo
Frequency Response:(all 3 dB): 7½ ips: 40Hz -18kHz
Wow and Flutter:(less than) 0.2% at 7½
Signal-to-Noise Ratio:better than 50dB
Sound quality rating:5 / 10
Long-term reliability rating: 5 / 10
The RK870 was a quarter-track stereo tape deck with separate record and playback heads, auto equalisation on three speeds and an aluminium die-cast transport chassis with a single 4-pole induction motor.
Other features included silicon modular solid-state record/playback preamplifiers, sound-with-sound and sound-on-sound recording, inching, vertical or horizontal operation, single “spill-proof” tape function selector knob, 3-digit tape counter and rear panel input and outputs.
Price when new was$119.95 in the US and £74 7s in the UK.
The accompanying vintage test report on the Get Reel Contemporary Classics CD gives a more detailed description of this equipment.
Overall distortion: less than 1.5% at 0 VU / Crosstalk: better than 60dB / Equalisation: NAB standard / Bias frequency: 105kHz / Inputs: microphone: 0.15mV for 0VU, 600 ohms, auxiliary: (low) 100mV 150Kohms, (high) 500mV 700Kohms / Outputs: external amp: 1V to 2.5V (variable) stereo headphones, extension speakers(8 ohms) / Dimensions: 12½ x 11¾ . x 6″ (317 x 298 x 152mm) / Weight: 18 lbs (8.2 kg) / : / quarter-track stereo