Tonearms — VPI Fatboy Gimbal 10-3D Tonearm

The Fatboy Gimbal 10-3D is a tonearm from VPI Industries and, according to the company, the first tonearm to combine a gimbal bearing with a 3D-printed armtube. VPI calls it the biggest advance in tonearm technology in five decades. It is designed with VPI turntables in mind but can also be mounted on decks from other manufacturers, and it gives buyers a full gimbal-bearing version of the Fatboy next to VPI's traditional unipivot arm.

Key specs that matter

The pivot-to-spindle distance is 258mm, effective length is 273.4mm and effective mass is 10.7g. Overhang is 15.4mm and the offset angle is 19.98 degrees. VPI quotes an average RMS distortion figure of 0.31%. The internal wiring is Nordost Reference Wire from end to end, and the arm cable plugs in through a Lemo connector.

Engineering and use context

The armtube is 3D-printed from epoxy resin and Delrin and changes shape along its length from a triangular to a circular section, a taper intended to cancel resonances. It is combined with copper, aluminium and steel parts. VPI President Mat Weisfeld explains that this mix of materials balances precision and rigidity at the point where the printed tube meets the finely machined back-stock. The counterweight works like a micrometer, can be adjusted in several dimensions and moves in steps of thousandths of an inch, which makes cartridge set-up easier than on earlier VPI arms. Adjustable side weights set azimuth, and VTA can be adjusted as well.

Pairing

With adjustable counterweight, azimuth and VTA, the arm accepts a wide range of cartridge types and weights. On a compatible VPI turntable it is a direct way to move from unipivot to gimbal-bearing operation, and the Lemo socket keeps the choice of tonearm cable open.

Alternatives

The VPI Fatboy Unipivot uses the same 3D-printed armtube with the resonance-cancelling taper but rides on a unipivot bearing, adjusted with setscrews on the side of the armtube and adjustable side weights.