Conference hips::uk_audioo

	There are a lot of myths surrounding the Linn Sondek, the
	most popular being that it's a pig to set up. It's true of
	early models that they did "go off" after a while, but this
	was overcome largely by the "Nirvana" mods, which replaced
	all the fixing hardware and springs with high-tensile steel 
	items coloured black, and locknuts all round. Any post-1982
	Sondek should have this, but earlier models can be easily
	upgraded if you're reasonably mechanically orientated, and
	patient - if not, consult your dealer! I hope this topic may
	help you.

	Although post-Nirvana Linns aren't prone to drifting out of
	adjustment, that doesn't mean regular servicing won't pay off,
	and to get the performance that makes the Linn stand out you
	need painstaking attention to setup. It isn't difficult, 
	or esoteric. As a general rule, everything that moves should
	be as free as possible, while anything that shouldn't move 
	should be very tight.

	How tight is very tight? This means as tight you can go, with
	normal hand tools (I'll list the ones you need later), not
	using extension bars and such, without deforming materials.
	The problem is that the ideal torque in any place is that
	immediately prior to threads stripping, not easy, except for
	the armboard screws.

	To understand why this tightness is required, it must be
	realised that the forces involved in LP replay range from
	ounces to several tons per square inch, often together and
	changing direction several times per millisecond. If any of
	this energy becomes spectrally shifted, as it will across a
	loose or compliant interface, then energy will not cancel in
	the subchassis as it should. Uncancelled energy then gets
	back to the stylus/groove interface causing colourations and
	loss of information. No turntable closes the loop perfectly,
	but any make of turntable will perform better if this is
	taken into account during a rebuild. What makes the Linn (and
	others like it) so costly is the quality of engineering needed
	to get the required energy transfer.

	Tools required for a Linn stripdown are as follows....

	Protect the stylus in some way, either by removal (MM),
	or using the guard (MC).

	Remove the outer platter and belt. Remove spindle;
	protect spindle bearing face from dust, etc., and plug
	the bearing housing hole with the red plug supplied
	by Linn - if you don't have this but need to tip the
	deck thru 90 degrees, then don't remove the spindle.
	This may restrict what you can do later, though.

	Remove the base. Remove the 4 wood screws at each end of
	the wiring strap (the metal cross-member that spans the
	underside). Remove the Valhalla motor control module
	(if fitted) from the wiring strap. Remove the locknuts
	that secure the wiring strap to the plinth; don't lose
	the P-clip that clamps the arm cable! The strap can now
	be removed, revealing 2 more locknuts holding the top
	plate to the plinth. Tighten these nuts as hard as you can.
	Take care not to bend the top plate, as this will misalign
	the motor, but slight "dishing" around the screwheads is OK.

	Remove the arm cable from the arm base, then remove - with
	great care! - the 3 wood screws holding the armboard to the
	subchassis, supporting the arm/board assembly as you go.

	If all 3 locknuts are removed from the springs, they and the
	subchassis will now come right out, exposing the locknuts
	which secure the suspension support bolts to the top plate.
	Tighten these as per the nuts holding the top plate to the
	plinth. Again, don't bend the top plate; it should be flush
	with the plinth. This can be done without removing the sub-
	chassis completely by removing just one spring at a time,
	but having the subchassis in situ may make the next step
	difficult, and you *must* have the deep socket or box-
	spanner to tighten the nuts.

	Ensure the two large woodscrews in the wooden blocks front
	and rear of plinth underside are tight. There are also some
	small woodscrews on the top which ensure good contact between
	top plate and these blocks, which should also be tight. Take
	care not to strip the holes, though.

	Make sure the 3 allen-head screws holding the bearing
	housing to the subchassis are tight. This can still be done 
	without removing the subchassis, through the hole in the
	top plate. It is essential that these are *very* tight. 
	Don't bend the subchassis.

	Tighten the 2 nuts securing the motor.

	You're now ready to rebuild. Before you do, check that the
	rubber grommets top and bottom of each spring are not
	perished; give each a light covering of French chalk prior
	to refitting.

	

	Rebuilding is basically the reverse of the stripdown.

	Check that the screws (or whatever method of fixing
	your flavour of arm uses) securing the arm to the arm-
	board are very tight. This is also a good opportunity
	to check cartridge screws are tight without stressing
	arm bearings. If you want fit the new Linn armboard,
	do it now (after fitting the arm to it, of course);
	prepare the woodscrew holes by screwing/unscrewing into 
	each hole.

	After refitting the subchassis (don't worry about
	suspension setup yet), *carefully* refit the armboard
	to the subchassis. Don't strip the screw holes, it
	means a new armboard if you do, but go as tight as
	you dare.

	Refit the wiring strap; don't forget the washers or 
	ground wires. Again, these nuts must be *tight*. 
	Don't forget the 4 wood screws. DO NOT fit the arm 
	cable/P-clip at this time, that is a crucial part of 
	the setup.

	Refit the Valhalla motor control module if you have one.
	Wires should be tightly fixed, and the on/off switch
	ribbon cable should be fully home.

	Fit the spindle back into the housing, very gently.

	Now you can start the set-up.
	

	You can jump in here if you're confident everything under-
	neath is tight, you don't *have* to strip/rebuild.

	Fit the belt. Before fitting, hold up between thumb and
	forefinger; the belt should dangle symmetrically, no
	curves in toward the centre. If there is, you have the belt
	inside out.

	Ensure the top grommets on the 3 springs are correctly seated
	in the subchassis.

	Fit the outer platter, and adjust the 3 suspension nuts until
	the platter looks parallel to the top plate and the armboard
	is about 1-2mm above the plinth/top plate.

	Grasping the spindle, gently move the suspension from side
	to side in various directions, feeling for any reluctance
	to move. This horizontal stiffness can be overcome by
	rotating one or more springs. This can take hours, since
	changing one can affect movement elsewhere, although it's
	fairly easy to get rid the worst stiffness in about 10 mins.
	It depends how fastidious you are. Don't forget the belt will
	cause an impression of stiffness in some directions.

	When you have this as good as you can, readjust the suspension
	height so that the armboard is level with the plinth and top
	plate - slightly low is better than slightly high. Check the
	armboard does not touch the plinth or top plate, and with
	reasonably even spaces on all four sides. If it's badly twisted
	one or more springs may be under torque; reseat them in the sub-
	chassis.

	Check the side-to-side movement again; it should now be slightly
	better. Check the bounce by tapping the platter where the inner
	and outer join, on a line between the spindle and the arm
	pivot. The bounce should be slowly decaying, not obviously
	damped, with little or no tendency to rotate; if not, go back
	two paragraphs.

	Plug the arm cable back into the arm base; fit the P-clip
	around the cable. The shape of the clip dictates that Linn
	arm cables require a 90-degree twist for the clip to grip
	tightly - and it must be tight. Using a screwdriver to pull
	the clip tight around the cable, fix the clip back to
	its mounting using the remaining locknut and flat washer.
	(You only had one of each left, didn't you?:-})

	Note how the armboard fits within its hole, then remove the
	plug from the arm. Is the armboard in the same place? If not
	you have either too much or too little cable between clip 
	and plug. You may have to repostion the clip on the cable, or
	you may get away with rotating the clip slightly. The arm
	cable must not displace the subchassis at all.

	If the arm cable is stiff, and reluctant to dress where you
	want it to go without moving the suspension, heat it with
	a hair dryer while setting the lie of the cable that does
	not interfere with the suspension.

	Do a final check of bounce and side-to-side movement; if
	all is not well, it can be redone without doing the arm cable
	all over again.

	Invert the outer platter, and spin up the deck while
	observing the belt on the motor pulley. The belt should ride
	mid-way on the transition between tapered and parallel parts
	of the pulley. The angle of the motor can be adjusted to
	achieve this, but Linn say you need a stroboscope or their
	speed checker to be sure the speed is 33.3333..... If it looks
	OK, leave it.

	All that's left to do now is fit the base back on, and enjoy.

.0�I, the moderators of this conference, or Digital can take any responsibility
.0�for damage, injury or expense that result from following procedures.
    
    I doubt Digital would take responsibility; are you sure you want to?
    
    [:-)] - but it pays to read carefully!!
    
    Keith
    
    PS Can someone update the DECnet remote node database on DRILL::,
    please [moderators?] - I am *not* on node MJS::

    re Keith's reply, of course, I meant "cannot". It isn't that I can't
    read, it's just that I can't type. ;-}
    
    It was a good day for errors. In .1, I referred to tools, but didn't
    tell what they were, so here goes.....
    
    You need:-
    
    a 5.5mm or 7/32" hollow shaft nut driver or box spanner
    an 8mm or 5/16"  	ditto		ditto
    (The  big nut driver must be deep enough to pass over a 3" bolt....)
    a #1 and #2 Pozidriv screwdriver (Philips will work, though)
    a medium (~5/32" wide) flat screwdriver
    a pair medium needle nosed pliers
    12mm or adjustable spanner
    5mm or 3/16"AF spanner
    1.3mm, 2mm, 3mm, 4mm Hex(Allen) keys. All but 3mm come with Linn
    tonearms.
    
    You also need some means of supporting the turntable which allows
    you to see and reach underneath. Dealers use a jig, but a dining
    table with a leaf removed, or a SO table/equivalent with the board
    removed will do. Due to the tightness of the nuts, etc, you need
    to exert more force than you realise, so whatever you use must be
    very firm.
    
    Have fun.
    
    Dave

    I have a Linn jig (and a selection of bit and pcb's useful for
    rebuilding LP-12).
    
    Although I do take my LP-12 to bits occasionaly I would recommend it to
    the faint of heart as you can do a lot more dammage than good -
    especially to Ittok / Ekos bearings.
    
    PS Getting gromit / P clip / Arm cable combination correct is very
    important - I should know, I spent a good few years working (?) on
    Saturdays for may local Linn/Naim/Rega/... dealer.

    re .7....
    "    Although I do take my LP-12 to bits occasionaly I would recommend it to
    the faint of heart as you can do a lot more dammage than good -
    especially to Ittok / Ekos bearings."
    
    Er, don't you mean you would *not* recommend, etc....? ;-)
    
    Very true though. I wrote off an armboard by overtightening the little
    woodscrews underneath. The shop said I'd never know how tight was too
    tight until I overdid it; they were right and and I was �20 worse off
    for a new one.....
    
    Dave
    

    look out for the new LP12 power supply (Called the LINNGO?) should
    be out soon for bout � 500.
    
    
    Rob.