Rockport Technologies Sirius II

The Rockport Technologies Sirius II turntable is a legendary, ultra-high-end reference phonograph renowned for its massive construction, advanced engineering, and uncompromising sonic performance.

• Plinth and Base:
  Material: Massive, constrained-layer damped granite plinth (approximately 250 pounds).
  Isolation: Supported by an advanced active pneumatic suspension, considered the most sophisticated isolation system available at the time of its release.

• Platter:
  Material: Constrained-layer damped stainless steel composite platter (predecessor model System III Sirius had a 62-pound platter; Sirius II is likely similar or even more advanced).
  Bearing: High-pressure, low-flow air bearing for both radial and thrust surfaces, ensuring virtually zero friction and exceptional precision.

• Drive System:
  Type: Direct-drive, utilizing an integrally mounted eddy current motor.
  Control: Feedback control loop with both phase and velocity servos, referenced against an ultra-precise on-board analog time standard (accuracy of speed: ±5 ppm).
  Run-out: Less than 5 millionths of an inch, no contacting surfaces, zero torque ripple.

• Tonearm:
  Type: Ultra-high-precision, critically damped air-bearing tonearm.
  Construction: Ensures the only mechanical contact in the entire system is between the stylus and record.

• Weight:
  Total Turntable Weight: Approximately 250 pounds for the Sirius II (System III Sirius was 535–550 pounds; Sirius II is likely somewhat lighter but still extremely heavy).

• Dimensions:
  Approximate: 18" × 24" (sources vary, but Sirius II is generally slightly smaller than the System III Sirius, which was 24" W × 32" H × 19" D).

• Accessories:
  Air Compressor: Included for the air-bearing system7.
  Anti-Seismic Base: Often supplied for additional isolation7.

• Performance:
  Speed Accuracy: ±5 ppm.
  Isolation: Exceptional, due to the combination of granite plinth, air-bearing, and active pneumatic suspension.
  Sonic Benefits: Extremely low noise floor, outstanding clarity, and unprecedented resolution of musical detail.