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INSTRUCTIONS FOR USE M O D E L S 3009 & 3012 PRECISION PICK-UP ARMS Manufactured by S.M.E. LTD - STEYNING - SUSSEX - ENGLAND - Phone STEYNING 2228 MACHINERY LTD., BRIGHTON UNPACKING Remove t h e m o u n t i n g template and from the carton. alignment p r o t r a c t o r N e x t remove the perforated centre fitting f o l l o w e d b y the t w o e n d fittings, w h i c h should be carefully disengaged f r o m e i t h e r end o f t h e a r m . S u p p o r t t h e arm w i t h o n e hand d u r i n g this o p e r a t i o n to avoid straining it. INTRODUCTION This pick-up arm has been built to the highest engineering standards and. as a precision instrument, demands v e r y careful handling and installation. T h e following instructions have been prepared to enable the user to benefit by the outstanding performance of which it is capable. Please read them t h r o u g h carefully B E F O R E U N P A C K I N G THE UNIT. T u r n the c a r t o n on its side and o p e n t h e b o t t o m flaps. Push e v e n l y o n t h e b o t t o m o f the cradle n o w e x p o s e d , s o that it is kept square, and eject f r o m t h e t o p of t h e c a r t o n . C a r e f u l l y r e m o v e the separately packed parts f r o m t h e w r a p p i n g s w i t h i n t h e cradle and place t h e m safely on one side. R e m o v e t h e a r m f r o m Its cradle by disengaging the bed plate f r o m the s l o t t e d card fittings o n e i t h e r side. U n t i e the tape holding the knife-edge bearings. D O N O T R E M O V E T H E R U B B E R B A N D W H I C H H O L D S T H E A R M I N ITS REST UNTIL DIRECTED. IMPORTANT. Rep/ace all packing pieces in the carton and save for possible re-use. The S.M.E. arm would be seriously damaged if transported in an improvised packing. ASSEMBLY As a precaution against damage in transit t h e S.M.E. a r m is packed w i t h t h e balance weights r e m o v e d . assemble p r o c e e d as f o l l o w s : — To Release t h e set s c r e w ' A ' in t h e base w i t h o n e of the hexagon keys p r o v i d e d (Fig. 2). T u r n t h e base to a p p r o x i m a t e position relative t o t h e arm rest w h i c h can be seen in Fig. 1. Relock the set s c r e w lightly. N o t e that t h e graduation marks o n t h e edge o f t h e bed plate s h o u l d face o u t w a r d s f r o m the t u r n t a b l e . Slide t h e balance w e i g h t o n t o t h e t o n e arm e x t e n s i o n , n o t i n g that t h e end r e m o t e f r o m t h e radial hole goes on first and that t h e radial hole should be underneath and o u t o f sight (fig. 2). A n internal spring-loaded ball holds t h e w e i g h t in any p o s i t i o n . T h e end cap complete w i t h w a y r o d and r i d e r w e i g h t is n o w fitted and secured by t i g h t e n i n g t h e set s c r e w 'B'. T h e part o f t h e w a y r o d w h i c h passes t h r o u g h t h e end cap s h o u l d be h o r i z o n t a l . MOUNTING T h e mounting template has instructions printed on it. C u t the necessary slot in the m o t o r board. If it is impracticable to position with the slot and turntable spindle on t h e same centre line it should be as near as possible. Bear in mind t h a t t h e range of adjustment afforded by the sliding base w i l l otherwise be reduced accordingly. Position the bed plate symmetrically o v e r the slot. Spike through each of the four r u b b e r grommets. Remove t h e unit. A spare wood screw provided is n o w screwed i n t o each spiked position in turn. T h i s screw is discarded and the unit fitted w i t h the remaining four screws which will e n t e r easily i n t o the holes already made without damage to t h e i r heads. Screw d o w n until screw shoulders touch the r u b b e r grommets and t h e n give each another half t u r n . ARM REST A D J U S T M E N T At this stage the arm rest should be re-positioned so that it is well clear of the turntable. Release the set s c r e w ' A ' slightly and t u r n the rest and pillar as r e q u i r e d , at the same time setting approximately for height in relation to t h e t u r n t a b l e . be made later after fitting t h e shell. Final height adjustment must Relock the set screw. FITTING A CARTRIDGE T h e S.M.E. shell is suitable f o r all standard p h o n o cartridges. Screws and pillars at A in. spacing permit d i r e c t mounting or use of a bracket when required. A special adaptor is available f o r Decca heads. C o n n e c t i o n s to the terminal pins in the shell are made using t h e tails p r o v i d e d — n o t by d i r e c t soldered connections. Damage to the shell w i l l result if this is attempted. CONNECTIONS These appear as figs 3 and 4 w h e n v i e w i n g t h e arm socket f r o m t h e f r o n t and c o r r e s p o n d w i t h t h e same numbers at t h e o u t p u t s o c k e t . F o r stereo cartridges use 1 and 2 f o r t h e left a n d right-hand channels and 4 the common negative. 3 (identified w i t h a y e l l o w spot at the o u t p u t socket) Is t h e m o n o positive. U s e 3 and 4 f o r m o n o cartridges and pre-amplifiers having a separate m o n o input socket. A l s o t h e m o n o tap of certain s t e r e o cartridges, e.g. Decca ffss. DO N O T USE 3 AS A S E C O N D S T E R E O N E G A T I V E or in the case of the Decca t h e s t e r e o o u t p u t w i l l be s h o r t e d o u t . T h e foregoing instructions assume t h a t t h e a r m s o c k e t w i l l b e used in its standard p o s i t i o n , fig. 3. It must be remembered that w h e n re-positioned f o r non-stand a r d h o r i z o n t a l 2-pin o r diagonal 3 and 4-pin plugs the relationship o f t h e connections w i l l b e diff e r e n t . T h u s , a 2-pin m o n o head ( O r t o f o n t y p e ' C ', f o r instance) w i l l engage contacts 3 and 2 and a 3-pin stereo head 3 and 2 f o r t h e t w o channels and 4 t h e c o m mon negative. T h i s must be c o n sidered w h e n making connections t o t h e o u t p u t plug. To permit this flexibility of use t h e screen c o n n e c t i o n has been kept separate. It is essential to c o n n e c t t h e earth tag t o t h e screen o f t h e amplifier connecting lead and to earth. Failure t o d o this w i l l result i n s e v e r e h u m , especially w h e n t h e arm i s handled. T h e m o t o r o f t h e t u r n t a b l e u n i t must also be earthed. FIG. 3 Arm socket positioned for standard 4-pin plug with horizontal pin arrangement. FIG. 4 Arm socket re-positioned for nonstandard horizontal 2-pin or diagonal 3 and 4-pin plugs by rotating through 45° (see fitting the shell, paragraph 2) ARM SOCKET (Viewed from front) Typical circuit using t h e Decca ffss utilising both stereo and mono outputs. T h e connection t h r o u g h 3 is the mono positive and provides an o u t p u t f r o m the lateral coil o n l y when using the ffss as a mono r e p r o d u c e r . It is shown connected to the mono Input socket at t h e p r e amplifier. If this Is not available o m i t this connection altogether and combine the t w o stereo channels, a s w i t c h for this purpose is provided on most stereo pre-amplifiers. It must be carefully noted that the Decca employs a common negative. 3 must n o t be connected to e a r t h as t h o u g h f o r a cartridge having seperate negatives or most of t h e o u t p u t will be shorted o u t . Cartridges having seperate negatives should have t h e m connected t o g e t h e r w i t h i n t h e shell t o pin 4. Fig. 5 SCREEN EARTH FITTING T H E SHELL LONGITUDINAL Remove the r u b b e r band holding t h e arm in its rest. T a k e care n o t t o allow t h e balance w e i g h t t o s w i n g t h e arm u p v i o l e n t l y . Insert t h e shell plug In t h e arm socket so that t h e locating pin e n t e r s t h e slot. Press inwards w i t h one hand and simultaneously s c r e w up the nut w i t h t h e o t h e r . T h e s c r e w t h r e a d w i l l engage t h e locating pin and d r a w t h e plug home. DO N O T OVER. T I G H T E N . Finally, check t h a t t h e b o t t o m of t h e shell is in a plane parallel to t h e t u r n t a b l e . If n o t , shell and n u t s h o u l d be grasped f i r m l y and gently twisted W H I L S T H O L D I N G T H E K N I F E E D G E B E A R I N G S FIRMLY IN E N G A G E M E N T . and allows this adjustment, T h e s o c k e t i s a f r i c t i o n fit i n t h e arm BALANCE M o v e t h e r i d e r w e i g h t as far back as it w i l l g o , towards the crank in t h e w a y r o d , and t h e n f o r w a r d u n t i l its f r o n t e n d coincides w i t h t h e first graduation mark. N e x t move t h e balance w e i g h t until the a r m assumes a level p o s i t i o n . T h e knife-edge bearings offer v e r y little f r i c t i o n so adjustment is critical. LATERAL BALANCE Place a s u p p o r t u n d e r t h e straight p o r t i o n of t h e arm as s h o w n In fig. 6. Slacken set s c r e w " C . " U s i n g a s c r e w d r i v e r or similar r o d , lift t h e arm f r o m a p o i n t behind t h e bearings. USE W I T H O U T SHELL A d j u s t t h e distance b e t w e e n t h e w a y r o d and t h e arm b y sliding laterally u n t i l b o t h C e r t a i n heads. O r t o f o n , E . S . L . , N e u m a n n , e t c . , can be plugged knife-edges leave t h e i r bearings simultaneously and remain level as d i r e c t l y i n t o t h e a r m socket i n place o f t h e S . M . E . shell. t h e a r m is lifted. BALANCING T i p p i n g t h e u n i t o u t o f level w i l l n o t cause t h e a r m t o swing w h e n If e x t r e m e accuracy is desired a f u r t h e r check Is possible by unscrewing t h e bed plate f r o m t h e m o t o r board. T h e S.M.E. arms I n c o r p o r a t e a unique s y s t e m w h i c h permits both it is perfectly balanced. longitudinal and lateral balancing. w i t h c a r t r i d g e , p r o c e e d as f o l l o w s : critical and must be made a little at a time. Having fitted t h e shell complete s e t s c r e w " C ". A d j u s t m e n t to this degree is somewhat Finally, re-tighten t h e S T Y L U S PRESSURE This is applied by moving t h e rider weight f o r w a r d along the way rod, each division represents 1/2 gramme at t h e stylus. Always start with the f r o n t of the weight coinciding w i t h the first graduation mark on the way rod and the arm balanced horizontally. From this condition the pressure applied at the stylus by forward movement of the rider weight is constant irrespective of the cartridge fitted and no pressure gauge is therefore needed. Re-check the longitudinal balance from time to time. ARM H E I G H T T h e main pillar is next adjusted so that when t h e stylus rests on the record the arm i s level o r v e r y slightly low A T T H E P I V O T E N D . Set screw ' A ' can now be finally tightened B U T NO M O R E T H A N IS NECESSARY TO H O L D T H E PILLAR. ARM CONTROL This special feature of the S.M.E. precision arm permits feather light lowering and raising of stylus anywhere on a r e c o r d . If the foregoing instructions have been carried o u t c o r r e c t l y , movement of control lever to the vertical position w i l l raise t h e stylus well clear of the record. To operate, start t h e turntable and sight the stylus ever the record using the white line on the front of the shell. Move the lever, allowing it to drop down. The stylus will now descend slowly on to the record. W i t h a little practice considerable accuracy of selection is possible. Finally, check that when a record is being played there is clearance between the crack of the arm control and the rubber grommet on the underside of the arm. The thickness of a piece of stout paper is a safe minimum. Insufficient clearance is corrected by lowering the pillar slightly, not by attempting to lower the bracket on the pillar. DO N O T INTERFERE WITH THE SET SCREW ' D 1 TRACKING SM.E. arms should be set to give zero e r r o r at 2 3/4 in. radius. An alignment protractor for this purpose is included. Place the perforation over the record spindle and lower the stylus into the pinhole In the protractor. Release the base clamping nuts (Fig. I) and move the base on it slldeways until the printed lines on the protractor are parallel with the centre line of the shell when viewed from above. Relock the nuts. The bed place has graduations so that when different cartridges are used, appropriate settings can be noted. Subsequent adjustment is then convenient and rapid. DYNAMIC LEVELLING This is the term given to the procedure of tilting the motor-board to neutralise the force pulling the arm towards the centre of the turntable. This force results from the rotating record trying to drag the arm forward along the centre line of the shell which, being offset in relation to the arm pivot, produces a turning moment about that point- It will be appreciated that this effect depends on, and reduces with, stylus pressure. It would not be practicable to alter the motor board levelling for each different cartridge used but we recommend a compromise. T i l t the complete motor board to that the edge of the turntable where the pick-up enters the record is 3/8in. lower than the point diametrically opposite. This looks a little unusual at first if you have been accustomed to a level turntable. The foregoing recommendation is the result of extensive experiment and provides the optimum condition for our arm. We do not recommend tests carried out with a blank disc as the results obtained can be quite misleading. The loading In lb. per sq. in, when a stylus makes a single point contact with a flat surface is immensely greater than in a groove. A blank disc of similar hardness to an L.P. record will be indented by a .0005" stylus even at 2 grammes pressure and there will be considerable inward pull, while substitution for a hard blank such as perspex may cause the same stylus to run outwards. The S.M.E. arm will perform equally well tilted 30 degrees inwards or outwards which suggests that the playing condition it engenders does not call for much improvement. MOTORS The performance of even the finest arm and cartridge can be spoilt by an indifferent or worn turntable unit. We cannot stress this too strongly. Often a unit which has given satisfactory service for mono will disclose shortcomings with a stereo pick-up sensitive to vertical vibrations. Use your S.M.E. arm only with a first-class turntable free from wear and mounted in accordance with the maker's instructions. If vibration is present overall reproduction will be affected, sometimes severely. AMPLIFIER C O N N E C T I O N S It finally remains to connect the output plug to the amplifier. Use light-weight coaxial or phono lead. Solder appropriate wires to the plug. Thread through the slot in the bottom of the screening can from inside. Insert the plug in its socket and place the can in position over the two spring clips. CONCLUSION DO N O T in any circumstances . . . Unscrew dashpot cover. The special fluid will be lost and can only be obtained from us. If the foregoing hut ructions are faithfully carried out the S.M.E precision arm will function perfectly. Strict observation of the following points will ensure continued trouble-free operation: Alter adjustment of pillar bearings. DO . . . Transport arm without removing balance weights and securing arm in its rest with a rubber band. Dust arm, and in particular knife-edge bearings, with a small soft brush. Despatch arm unless packed as supplied in the special carton with all fittings in place. Handle as befits a high-grade precision instrument. Over tighten any of the set screws or interfere with the setting of one marked ' D ' which, if over tightened, might distort pillar. Locate main amplifier well away from motor board, at least 6 ft. if possible. Mains transformers radiate a strong magnetic field which will spoil the performance of many cartridges. Loudspeakers cannot reproduce clean bass and hum simultaneously. Allow wiring to become twisted up by rotating base before fitting. Apply lubricating oil.