Rek-O-Kut B-12H S

The Rek-O-Kut B12H S is a high-end idler-wheel turntable from the Rondine Deluxe series, renowned for its precision engineering and audiophile-grade performance. 

Drive System and Motor

• Equipped with a hysteresis synchronous motor, ensuring consistent speed accuracy and minimal speed drift.

• Uses a single neoprene idler wheel (ground for concentricity) driven by a stepped motor pulley for 33⅓, 45, and 78 RPM speeds.

• Speed selection via a 5-position rotary knob (33/Off/45/Off/78), with automatic disengagement in "Off" to prevent idler wheel wear.

Platter and Bearing

• Cast aluminum platter, dynamically balanced with a cork-neoprene mat and strobe markings for speed verification.

• Features a single-ball thrust bearing for low friction, paired with a precision-ground spindle.

Performance Metrics

• Wow and flutter: As low as 0.09% after restoration.

• Rumble: Rated -39 dB (NAB), with noise 50 dB below average recording level due to the hysteresis motor.

• Startup time: 1/6th of a revolution for immediate speed stability.

Tonearm and Compatibility

• Originally paired with the Rek-O-Kut S220 Gyropoise tonearm (a high-mass design for 78 RPM playback).

• Restored units often feature premium arms like the Ortofon RS-212 or SME 3012, optimized for low-compliance cartridges (e.g., Denon DL-103).

Restoration Notes

• Critical upgrades include idler wheel rebuilding (brass or neoprene replacements), motor capacitor replacement, and re-lubrication of bearings.

• The plinth is often custom-built or refinished to dampen vibrations, with original dimensions of ~16.5" × 16.75" × 8.5".

Variants and Legacy

• The B12H S distinguishes itself from the standard B12 with its hysteresis motor (vs. induction) for quieter operation.

• Later models like the T12H (80 lbs) emphasize massive plinths for improved bass response and dynamics