Turntables, Arms & Cartridges

Such are the ‘horror stories’ told of early-generation Decca carts, I’ll admit to studiously avoiding ever letting one near my precious (and irreplaceable) test records. But who knew? The thoughtful combination of medium-power AlNiCo 5 magnets and a folded ‘soft iron’ armature/cantilever in this Decca Reference Type II has traded a slightly reduced output (1.65mV vs. a claimed 5mV re. 1kHz/5cm/sec for the older London Elliptical), and a mere 13dB separation, for a superb 0.08dB channel balance, moderate distortion, and surprisingly secure tracking. Unequalised lateral distortion is 0.8% through the +9dB groove (re. 0dB at 315Hz/5cm/sec), rising to 1.5%/+12dB, 2%/+15dB and 3% at the maximum +18dB modulation – but this reflects a generator non-linearity rather than mechanical mistracking.

Distortion on vertical cuts is higher, from 2.1%/+9dB to 5%/+12dB, but the trend reverts at HF with lateral THD [black infill, Graph 2] exceeding vertical distortion. The combined stereo distortion peaks at 10%/7kHz [re. –8dB at 5cm/sec; dashed trace, Graph 2] where there’s a (presumed) bending mode in the iron cantilever. Medium-heavy effective mass arms, with extra damping, are still recommended to accommodate the ‘stiff’ 10/12cu compliance and vigorous arm/cart resonance. The asymmetric generator design [see boxout] is also revealed in the contrasting lateral and vertical responses [black/red traces, Graph 1] although, once again, the combined stereo response is remarkably flat and extended to within +1.25dB on the left and +5dB on the right (re. 20Hz-20kHz). VTA, set by the cut of the Paratrace stylus profile and ~5° rake angle of the cantilever and diamond, is calculated at 15° with the arm parallel to the LP. PM