SME’s Standard Nine-Inch Arm
The SME M2-9 is the nine-inch model of SME’s Series M2, the arm SME describes as the standard of the range and the one most frequently used. Made in England, the SME M2-9 brings well-tried SME principles to a lightweight tube of highly polished stainless steel, damped from within, and joins that tube to a detachable magnesium headshell with azimuth adjustment, a tungsten counterweight, and ball races of superb quality for both axes. In SME’s judgement the result is stiff and rigid enough for any type of cartridge.
A Headshell Cast in Magnesium
Pressure die-cast in magnesium, the headshell is light and rigid at once, and SME’s collet fixing, ingenious in design, gives shell and tube the firmness of a single piece. Before the final tightening, the same collet allows the azimuth to be corrected, so the stylus can be set truly vertical when viewed from the front. The shell is detachable: as the shell slides home, sprung contacts inside the plug at the end of the tube take up the connection, and a clamp bolt locks the joint.
One Weight for Balance and Force
The SME M2-9 relies on a single-element balance system, refreshingly simple in use. The tungsten weight first brings the arm into balance with the cartridge fitted, then moves forward on a precision screw thread to apply the tracking force, an arrangement that, SME notes, keeps system inertia to a minimum. A backlash eliminator keeps every setting exact, and letters around the face of the weight mark the quarter turns, so a chosen force can be read at a glance and found again later, for cartridges from five to twelve grams.
Polished Steel, Damped Within
Highly polished on the outside and internally damped, the stainless steel tube is the element SME credits for a sparkling, uncoloured reproduction of the record. Low-friction ball races, fully shielded, carry the arm in both planes of movement, and a thumbwheel raises or lowers the pillar to set the arm height. Internal wiring of LCOFC continues into SME’s balanced hybrid lead, whose RCA plugs are gold-plated, while a separate ground wire runs to the phono stage.
Set-Up with SME’s Own Gauges
Installation follows SME’s careful sequence, and the tools come with the arm. A mounting template prepares a board not yet cut for an SME arm, the alignment protractor doubles as a height gauge for setting the tube level, and three hexagon wrenches complete the kit. A sliding base on the bedplate sets the horizontal tracking angle, anti-skate follows the traditional weight-and-filament pattern, and a fluid-damped control lowers the stylus with a smooth, unhurried descent. Where the floor transmits severe vibration, the arm is prepared for SME’s accessory fluid damper, the FD-M2, and SME’s care advice is brief: treat the arm like a camera, and keep oil away from every part.
The M2-9 Among SME’s Arms
Two relations help to place the SME M2-9. The SME M2-9R keeps the nine-inch geometry and the same effective mass, but carries SME’s aluminium S2-R headshell on two draw pins and a two-stage counterbalance for heavy cartridges and plug-in heads. The SME M2-12 shares the magnesium headshell and single-element balance of the M2-9 on a twelve-inch tube, for turntables designed around the longer arm.
Advice and Collection in London
After an online reservation, Audio Lounge sets the SME M2-9 aside in the Wigmore Street showroom, ready to be picked up in person. Ahead of collection, the staff will gladly discuss turntables already cut for an SME arm, a partnering cartridge from among the moving coil cartridges Audio Lounge carries, and a matching phono stage. SME’s other arms sit beside the M2-9 in the full range of tonearms at Audio Lounge.
About SME
SME’s first precision pick-up arm appeared in 1959, designed by Alastair Robertson-Aikman for his own hi-fi and put into production after friends in the audio industry saw the prototype; the Scale Model Equipment Company he had founded in 1946 became SME Limited that year. By 1962 the Series II came in nine-inch and twelve-inch versions, the R type Series II of 1980 added a ten-inch length to the pair, and the Series M2 keeps that choice of length alive today. Steyning in West Sussex remains home to SME’s audio manufacturing, together with precision parts for the aircraft, Formula 1 and medical industries. Explore the SME turntables and arms that Audio Lounge presents in London.
Questions About the SME Series M2-9
What is the SME Series M2-9?
The SME Series M2-9 is the nine-inch precision pick-up arm of SME’s Series M2, made in England and supplied without a cartridge. The SME M2-9 joins a lightweight, internally damped stainless steel tube to a detachable headshell of pressure die-cast magnesium, a tungsten balance weight on a precision screw and fully shielded ball races. SME names the M2-9 the standard arm of the range, the model most frequently used.
How does the SME M2-9 differ from the M2-9R?
In headshell, cartridge range and wiring. The SME M2-9 fits a magnesium headshell held in a collet, balances cartridges of 5 to 12 g on one weight and tracks at no more than 2.5 g, with LCOFC wiring and a net weight of 584 g. The M2-9R uses SME’s aluminium S2-R headshell with draw pins, a two-stage counterbalance for cartridges to 38 g, forces to 5 g and Silver Litz wiring. Effective mass is identical, at 9.5 g.
Should I choose the SME M2-9 or the M2-12?
Let the turntable decide. The SME M2-9 has a spindle-to-pivot distance of 215.4 mm, and SME calls the nine-inch arm the standard model, the one most frequently used. The M2-12 asks for a deck made for twelve-inch arms, at 295.6 mm from spindle to pivot, and in return the maximum tracking error falls from 0.013 degrees per millimetre on the nine-inch arm to 0.010, for an effective mass of 12 g instead of 9.5 g.
Which cartridges suit the SME M2-9?
Cartridges weighing 5 to 12 g, balanced by the single tungsten weight alone, with a tracking force no higher than 2.5 g. SME describes the SME M2-9 as suited to a broad range of cartridges, including medium and low compliance designs. The standard 12.7 mm fixing centres apply, SME packs a pair of #3-48 UNC alloy screws 11 mm long with nuts, and the colour-coded leads push onto the cartridge pins, never soldered. The cartridge is chosen separately.
Does the SME M2-9 suit my turntable?
Yes, where the deck is cut to accept an SME arm, and SME’s template guides the cut where the deck is not. Allow 215.4 mm from spindle to pivot, 46 mm of depth under the board, an arm height adjustable from 63 to 87 mm above the board and 51 mm of rear clearance for the balance weight. The FD-M2 accessory damper answers severe floor vibration, and Audio Lounge is happy to confirm the fit for a given deck.
How do I fit the headshell to the SME M2-9?
With the 2 mm wrench. Release and remove the clamp bolt, present the shell to the tube with the half-round keyway near the front, and press on until the spring-loaded contact pins in the tonearm plug compress. Align the bolt hole with the keyway, insert the bolt until the bolt meets the nut, and tighten lightly. To remove the shell, unscrew the bolt, press the shell on just enough to ease the pins and lift the bolt out.
How is tracking force set on the SME M2-9?
By turning the balance weight itself. With the cartridge fitted, balance the arm so the tube sits level or slightly low at the front, raise the arm on the lift, then rotate the weight anti-clockwise: one full turn adds 1.0 g and each of the letters A to D on the weight marks 0.25 g, so 1.5 g takes one and a half turns, up to 2.5 g. Anti-skate then goes in the groove that matches.
Which measurements define the SME M2-9?
The SME M2-9 has 9.5 g effective mass and weighs 584 g net. The stylus sits 233.2 mm from the pivot, with 17.8 mm of overhang, 23.63 degrees of offset and a linear offset of 93.47 mm; the null points fall at radii of 66.04 and 120.90 mm, and tracking error tops out at 0.013 degrees per millimetre. LCOFC wiring feeds a 1.2 m balanced hybrid lead with gold-plated RCA plugs.
What comes with the SME M2-9?
Beside the arm and the detachable headshell, the pack holds the bias weight with the bias guide, the audio lead, a mounting template, an alignment protractor and the instruction book. The hardware covers a finger lift with two washers, a pair of alloy cartridge screws with nuts, four M3 x 20 mm button head screws with four nuts and four washers, four more for mounting the arm, and hexagon wrenches of 2.0, 2.5 and 0.89 mm, plus a warranty card.
How do I reserve the SME M2-9?
Online, then collect in London. Once reserved on this page, the SME M2-9 is held for collection at Audio Lounge’s Wigmore Street showroom, since the arm is not sent by post. Questions about turntables, cartridges or set-up are welcome beforehand, whether by telephone, by email or during a visit.
