Country of Manufacture:Japan
Speeds: 3 3/4, 7 1/2, 15
Max Reel Size("): 10.5"
Number of heads: 4
Dimension: 18 x 17.5 x 10.25" (456 x 446 x 258mm)
Head Composition: Sendust
Head Configuration: Stereo - Stacked
# Motors: 3
Voltage(s): 100v Japan, 110-120v, 220-240v
Frequency Response: 30Hz - 30kHz at 15 ips +-3dB
Wow and Flutter:0.12% at 3¾ ips .04% at 7½ ips. .02% at 15 ips
Signal-to-Noise Ratio:60 dB NAB
Sound quality rating:7 / 10
Long-term reliability rating: 9 / 10
Weight: 57.2 lbs (26kg)
Perhaps trying to make up for lost time and to show that Technics was in fact a real contender in reel to reel tape recorders, they released 7 models in 1978, first the RS-1500 and shortly thereafter the RS-1506, RS-1520, RS-1700, RS-1800, RS-10A02 “R&B Series”
The RS-1500 is a half track Record/Play with switchable quarter track head using the RP-2224 headlock. It has the Isolated Loop tape path developed by Technics with really low wow and flutter (.018%) that also keeps down modulation noise.
A a very smooth and stable tape path using a large 34mm capstan and 2 pinch rollers combined with an electronic tension control system completes this transport. Tape tension on the Isolated Loop tape path is low compared to many other machines, so for those using older tapes with rippled edges, this may not be the ideal.
A Quartz-Locked Direct-Drive Capstan Motor completed the well-designed assembly.
Logic controlled electronic braking, which applies reverse torque to the motor prior to deploying a mechanical brake, results in very smooth transition between function selections and virtually no tape stretch.
Control functions included a three position speed control, remote timer, start, meter sensitivity, mike attenuator, source tape monitoring (separate for each track), three switch positions for bias and equalization, record track selection levers, and a tape counter indicating minutes and seconds at 38cm/s per second 10½ ”
Two good quality VU’s were fitted, but transients still under-read appreciably and no peak indicators were supplied. The recorder could also be used with a 24V DC power supply.
Stereo separation: better than 50dB / Harmonic distortion: 0.8% / Erase ratio: -68.5dB / Rewind speed: 2 mins 15 seconds for 3600ft on 10½ ” reel / Inputs: mic: 0.25 mV, 4.7 Kohm (jack plug) line: 60 mV (phono plugs) / Outputs: 600 mV (phono plugs) / Half-track stereo with quarter-track playback head
Technics isolated loop system
The Technics single capstan system offered advantages over double capstan as variations in the speed of two capstans and the pressure of the two pinch rollers to maintain the desired temp tape tension makes speed and tension adjustment complex and difficult often increasing the tape tension which is not desirable. The relatively long distance between the two capstans over which the which the tape must stretch contributes to higher modulation noise and scrape flutter. In contrast the Technics single capstan system maintains exactly the same speed and pinch roller pressure on both sides of the capstan. The wide contact area between the pinch rollers and the single extra-large capstan allows for lower tape tension, about 80 g and very steady because the tape path between the capstan and the reversing roller is relatively short. So modulation noise, wow & flutter and level fluctuations are dramatically reduced. Add to this the quartz locked slow speed direct capstan drive system, aided by tension controlled direct drive reel motors and air dampened tension rollers the Technics isolated loop system achieves excellent overall performance.