Проигрыватели виниловых дисков — Wilson Benesch GMT One

The GMT One System is a complete turntable installation from Wilson Benesch of Sheffield, announced in May 2019 to mark the company's 30th anniversary, and a prototype went on display at Munich HIGH END 2019. It grew out of the Mondrian Project, a collaborative development that ran for more than 20 years and received grant funding in the UK and Europe. The package combines motor, drive electronics, tonearm, cartridge, step-up transformer, isolation and a dedicated rack, with a total system weight of 369.5 kg.

Key specs that matter

The OMEGA Drive motor is a synchronous three-phase unit 381 mm in diameter with 21 coreless, slotless poles and zero cogging, and on its own it weighs 14 kg. Speeds are 33.3, 45 and 78 rpm, adjustable in 0.01 rpm increments. Time-average torque is 0.718 N.m at 1.2 A RMS at 33.3 rpm, RMS torque ripple is 0.001342 N.m, and wow and flutter is listed as not measurable. The GRAVITON Ti arm has an effective length of 304.8 mm, a mounting distance of 291.6 mm, an 18 degree offset angle, 13.2 mm overhang and an effective mass of 14 g.

Engineering and use context

Wilson Benesch calls the OMEGA Drive the first axially oriented, precision magnetically geared turntable drive, a patented layout that uses neither a belt nor an idler. The ALPHA Drive electronics feed three sine waves through three linear class-A amplifiers to the poles, with timing taken from an 11.2896 MHz quartz crystal. The single-piece armwand is moulded from carbon fibre in a quadruple helix with a graphene epoxy matrix and a Rohacell sandwich section, and deflects 0.003 mm under a maximum stress of 8.5 MPa. It turns on a kinematic three-point bearing and is wired internally with silver and Teflon. A linear piezo actuator sets VTA with 1 nanometre repeatable precision. The TESSELLATE Ti cartridge has a titanium body with an internal lattice and a choice of boron, sapphire or diamond cantilever. The LeVeL isolation system lifts the deck on four microprocessor-controlled pneumatic rams with a resonant frequency of 1.7 Hz, supplied by an oil-free medical-grade compressor.

Pairing

A STAGE One step-up transformer, mounted overhead on the arm, raises the moving coil output before it reaches the phono stage, so the rest of the chain needs an input suited to that stepped-up level. The R1 rack houses both drive units. Speed, VTA and other functions run from the WB GMT Control app on a smart device over a preconfigured wifi router that does not connect to the internet.

Alternatives

The Wilson Benesch Prime Meridian System is another turntable system in the company's current range.