Technics SP-10mkII
¥ 150,000 (around 1976)
Commentary
The DD turntable was developed with the aim of becoming a standard prototype for performance comparison by putting in all the technology and know-how accumulated since the development of the SP-10.
More than 1300 units of SP-10mkII were used for broadcasting stations in 25 countries.
It uses a crystal oscillator for phase control and achieves a rotational speed deviation of ± 0.002%. As a result, the error after 30 minutes of LP performance is ± 0.036 seconds, exceeding the detection limit for humans.
With a starting torque of 6 kg ・ cm, the diameter is 32 cm, the dead weight is 3 kg, and the inertial mass is 380 kg ・ cm.2The turntable reaches normal rotation in only 0.25 seconds at a rotation angle of 25 degrees.
By using both a mechanical brake and an electronic brake that instantaneously operates a reverse rotation drive circuit, the turntable is stopped at a rotation angle of 30 ° for 0.3 seconds.
This drive circuit is also operated for speed change, and the rated speed change is made possible at the moment of operation.
Achieves strong load fluctuation torque that does not change rotational speed even with 1 kg of needle pressure.
A crystal oscillator is also incorporated in the lighting of strobe neon tubes. The stripes, which were previously required for each rotation speed and power supply frequency, are now in one row, making it possible to detect rotational speed with extremely high accuracy.
The reverse side of the turntable is also covered with rubber sheet to improve vibration isolation characteristics.
Equipped with a remote controller, instantaneous start / stop can be done at hand as desired.
.JPG)
Model Rating
| Type | Direct drive turntable |
| Drive system | Direct drive |
| Motor | Brushless DC motor |
| Drive system | Quartz phase locked control |
| Turntable | Diameter 32.0 cm Aluminum Die-cast, 3.0 kg |
| Number of revolutions | 33 1/3, 45, 78.3 rpm |
| Starting torque | 6 kg / cm |
| Start-up characteristic | Constant speed at 0.25 seconds (33 1/3rpm) |
| Load variation | 5 kg / cm or less 0% |
| Rotational speed deviation | Within ± 0.002% |
| Wow and flutter | 0.025%W.R.M.S(JIS C5521) |
| Signal-to-noise ratio | 78dB(IEC98A weighted) |
| Pwer | 100 VAC, 50Hz/60Hz |
| Power consumption | 16W |
| External dimensions | Body : Width 368.5x Height 102.5x Depth 368.5 mm Power Supply : W 110x H 83.5x D 370 mm |
| Weight | Body : 9.5 kg Power Supply : 3.8 kg |
| Remarks | Additional depth of 85 mm is required when the plug is inserted. |