Micro Seiki BL-91 (L)

 Belt Drive Turntable System (Armless)

Many manufacturers have been promoting the direct-drive motor at the expense of precision materials and manufacturing techniques. While direct-drive is capable of remarkable speed accuracy, the system does nothing toward maintaining that accuracy against the inevitable destructive effects of aging.

Our  philosophy is that there isno substitute for quality, precisoin and tank-like ruggedness.

 The BL-91 (L) turntable is the ultimate expression of that philosophy. Staring with a massive, thick,  12,2inch platter and employing special-alloy bearings machined and polished with techniques usually reserved for turbojet engines, Micro's engineers have devised an exclusive oil-bath damping system to support the entire rotating assembly in complete isolation from all mechanical resonaces.

A precision-ground drive belt connects the rotating assembly to the brushless, servo-controlled motor with total isolation from motorgenerated vibration. In fact, the BL-91 (L) is probably the smoothest, most vibration-free device of its kind ever built.

 Rotating Assembly

The massive platter sits atop an incredibly thick, 16 mm main shaft. Its concentricity is machined to within 0,4 microns. The bearing material is a special alloy lubricated by and suspended in a unique oil-bath damping system. Not only does the system negate the need for periodic user lubrication, it is unaffected by temperature changes and aging.

 Drive System

The brushless, servo-controlled motor is of the outer-rotor design and uses sophisticated electronic circuitry to maintain speed acciracy. The specially-engineered, low-tension drive belt is , made of a carbon/urethane compound for maximum longevity and is pround to a precise thickness of 0,45 mm. Motor speed is user variable.

 Electronics power Transformer

To service the servo electronics, a special transformer with a cutless core was developed. This extremely low-flux device reduces to near zero magnetically-induced hum when used with a moving-coil phono cartridge.

 Turntable Base

The base of the BL-91 (L) is made completely of multi-laminar natural woods,a dense, sturdy design that prevents the transmission of resonances and distortion forces. It is finished with hand-rubbed, natural-ebony veneer suspended on four sophisticated, anti-feedback feet.

 Brass TonearrmMounting Plate.

The tonearm mounting plate on the BL-91 is solid brass. It weighs 1,5 kg (2,0 kg for BL-91L). This plate keeps the tonearm fulcrum rigid, assuring accurate tracing angles and minimal tonearm resonances.

The standard plate will fit the following arms;  Micro Seiki, Audiocraft, Technics. Teac, Denon, JVC

Optional mounting plates are available for SME, Grace and other quality arms.

Specifications

Drive System:  belt drive

Speeds (selectable):  33-1/3 and 45 rpm

Speed Variation:  User variable to  ±6%

Wow and Flutter:  0,025% WRMS

Signal-to-Noise Ratio:  75 dB (DIN B)

Drive Motor:  4-pole, 6-slot outer rotor brushless type, servo-controlled

Platter Diameter:  310 mm (12.2")

Platter Weight:  3,5 kg (incl. Rubber mat)

Platter Material:  Diecase aluminum

Platter Moment of Inertia:  600 Kg-cm² (with rubber mat)

Base Construction:  Multi-laminar natural wood

Finished:  Hand-rubber natural ebony

Power Requirements:  120, 200 - 240 V 50/60 Hz

Power Consumption:  4 Watts max.

Dimensions BL-91 / BL-91L (W x D x H):  532 x 440 x 175 mm / 600 x 472 x 186 mm

Weight BL-91 / BL-91L:  16 kg / 22 kg