SME Series IV Tonearm

Series IV Tonearm

The Series IV precision pick-up arm owes much to the technology developed for the acclaimed Series V. Although presented at a lower price it retains the unique one-piece magnesium tone-arm, dual-lock base and other advanced features listed.

The Series IV is a worthy relative of 'the best pick-up arm in the world' with a sonic performance reflecting the care and attention to detail underlying its design and manufacture.

  • Unique one-piece pressure die-cast tone-arm utilising the advantages of magnesium, replaces conventional fabricated construction.
  • Internal constrained layer damps minute residual vibration leaving the tone-arm acoustically inert.
  • Fine machined cartridge platform, enamel free to avoid interface resonance.
  • Stainless steel cross shaft, ground and thread ground. Carried in massive yoke on 10mm ABEC 3 ball races. Axis at record mean level to minimise warp-wow.
  • Unique assembly gives high rigidity and allows bearings to be critically adjusted before tone-arm is fitted.
  • Stainless steel vertical shaft, ground and thread ground, with integral 16mm diameter flange to couple shaft and yoke.
  • 23mm diameter steel pillar, heat treated, ground and honed, carries two 17mm ABEC 7 ball races, widely spaced to resist tilt.
  • Anti-skate control operates through tension spring and filament. Dial corresponds with VTF and has positive OFF position.
  • Lowering/raising control gives smooth positive action. Height of lift can be adjusted.
  • Dual-lock base provides movement control with high rigidity.
  • Tungsten-alloy balance weight carried on damped two-point suspension. Extra-low inertia design assists warp riding.
  • Underslung weight housing corrects centre of gravity and provides non-reflective tone-arm termination. Adjustment leadscrew journalled in twin ball races with lever clamping.
  • Swivelling damped output socket minimises vibration transmission in sub-chassis use.
  • Reference lines on tone-arm facilitate VTA setting.
  • Fine adjustment of horizontal tracking angle (HTA).
  • New design alignment protractor sets HTA with great accuracy.

Series IV Dimensions  Series IV Specifications 
A - Distance from pivot to stylus 233.15mm Effective mass 10.0/11.0g
B - Distance from pivot to turntable centre 215.35mm Cartridge balance range 5 - 16g
C - Cartridge fixing centres 12.70mm Vertical tracking force 0 - 3.0g(30mN)
D - Offset angle 23.635° Maximum tracking error 0.012(degrees per mm)
E - Linear offset 93.47mm Null points Inner 66.04mm
Outer 120.90mm
F - Overhang 17.8mm Audio lead Length 1.2m
Capacitance 140.0 pF per channel
Resistance 0.145 ohms per conductor
G - Height above mounting surface max. 87.90mm
min. 56.40mm
Internal wiring Capacitance 15.0 pF per channel
Resistance 0.535 ohms per conductor
H - Height of record surface above mounting surface max. 57.90mm
min. 26.40mm
Output plug and socket DIN 5-pole 240°
J - Depth below mounting surface 56.75mm Weight net 700.0g
K - Radial clearance for balance weight 73.0mm
L - Clearance between cabinet lid and record surface assuming cartridge height at 17.0mm 35.0mm