One of my first posts in this blog was regarding the servicing of the Pioneer PL12D turntable, and that has proven to be the most popular by a significant margin. The Pioneer PL12D had its competitors, and probably the most popular alternative was the Trio Kenwood KD-1033 turntable. I use both names (Trio and Kenwood) as the company operated under different names in different markets. In the UK they were Trio, possibly because the brand Kenwood was most famous here for food blenders. 95% of a KD-1033 is similar to Pioneer PL12D, and servicing them is very much the same process. Both are belt drive , have an AC synchronous motor, mechanical speed change , a main bearing, sprung top deck and rubber motor mounts. the KD-1033 uses a different type of anti skate mechanism, employing a thread and weight. The plinth is shallower with an internal cross brace. One aspect that is different is the design of the main bearing, and servicing it is a little harder than a PL12D. The ...
Introduction
I got back into vinyl records via my son, who started to collect LPs and i decided he should get a turntable as a surprise Christmas present back in 2011. I was an avid audiophile in the late 70s and my father had a great system,including a Thorens deck. With the arrival of CD, I whole heartedly embraced that format and hadn't owned a deck since around 1981. I decided that a decent but cheap second-hand deck would be ideal for my son, it wasnt a main present, more a novelty to see if he liked the format, so i didnt want to get a more expensive Thorens or Rega, brands i remembered from my past. Why my son had started buying vinyl without a deck I'm not sure, I think he liked the aesthetic and tactile element of LPs, which i completely understand.
Looking on ebay, many of the decks i remembered were going for high prices second hand, and in the end i bid for and won a humble NAD 5120 . I looked for decks close to where i lived as i reasoned that without the original packing, delicate turntables wouldn't travel well. The price was good, around £20 i recall, and the seller was quite close to me, so i collected it. I had a vague memory of the NAD having some strange flat arm, and looking unlike other decks. I also recalled visiting Brighton around 1980 , and popping into a Hi Fi shop ( when such things were common), which stocked the NAD brand. The salesman was talking to a customer about the new wonder-amp, the NAD 3020, which was getting rave reviews and being coupled with very high end turntables including the Linn Sondek LP12. The salesman, as i recall, lowered his voice and said that NAD were going to bring out a Linn-killer deck for £100, and it was being built "behind the Iron Curtain", hence cheaper production costs, and the customer should delay any purchase til it came out.
It was a long time ago, but it stuck with me as I remember thinking "good" - Linn were the darlings of the magazines and their dealers were zealots .
Fast forward to December 2011 and I had a NAD 5120 , purchased secretly as a surprise for my son. I needed to test that it worked. I had an A&R Cambridge A60, which had a dedicated DIN phono input, and a pair of RAM 200 speakers, both of which belonged to my father and I helped choose with him. the speakers were made around 1980 by RAM, a long gone but fondly remembered British speaker manufacturer from Norfolk
The deck came with an unidentifiable cartridge so i ordered a budget Audio Technica AT95 on-line.
I'd heard the deck play when i collected it and it seemed OK though there was a little hum.
Its Czech , and its a Tesla !
I was immediately struck by how different this deck was in design. Substantially
plastic, though its substantial plastic, with a very strange flat arm featuring a balance weight on a spring with an oil damping container on the arm; a lid with no end pieces, just high side "cheeks" on the plinth, and a strange platter that seemed to also be a mat. All finished in the NAD dark olive green . This truly was unusual, like a Citroen 2CV is an odd car.
I did some research on the web, mainly the wonderful vinyl engine web site and its associated forum, which has many friendly and helpful members.
I discovered that the deck was in fact a Czech design and in fact was simply a NAD re-badged version of a turntable widely sold on mainland Europe as the Tesla NC470, built in the Tesla Litovel factory in what was then Czechoslovakia. The designer was Jiřà Janda , about whom I could find very little, but some of his patents are here
He developed a number of audio products under the noses of the authorities in then Soviet-era Czechoslovakia through Audio clubs where members effectively made amps and equipment as part of the club. It also appeared that many of his ideas went into the deck, built by Tesla, who perhaps were a distant relative of Pro-ject, one of the few remaining turntable manufacturers in Europe. It was intriguing and part of the purpose of this blog was to try and find out some more history of the development of this deck. Perhaps someone out there knew Jiri or worked on the development of this deck, if so I would love to hear from you. I did find out that Jiri died in 1993, a short obituary can be found here , and a few pictures of him exist on the web and he looks a very kind man. Here he is with his wife Irena, a very skilled animator.
So i guess that the old saying that, necessity is the mother of invention, was true with this deck. I have come to appreciate just how clever the design of this deck is, and I guess that , where a material,technology or method was unavailable , a clever alternative was figured out. That flat arm, with its anti-resonance balance weight being a case in point.
I also discovered that while NAD actively promoted the deck as having a floppy arm, they later appeared to loose faith and reverted to a more conventional round arm for the deck.
( Actually the arm is not floppy, its made of a ruler shaped piece of circuit board, and while it can be flexed , this is not normal, indeed the adverts NAD had showed it being bent over. do not do this as it will do no good to the copper tracks along the flat arm).
So you can see examples on ebay with both a flat arm and a round tubular arm. You can even swap arms as the arm simply plugs into a 4 hole socket which also forms the vertical bearing. Over time I have had a number of these decks pass through my hands in addition to the original flat arm example, as i have acquired spares and repairs decks to try and get them working.
Variations on a theme
I'm not sure what the start and end dates of the production of these decks was, I'd guess from the early 80's to maybe the late 80's.
Versions i have encountered are :
Versions i have encountered are :
- Original flat arm model with orange bulb at front. Inside a DIN socket plug is used as a solder junction between the fine wires from the arm bearing to the signal cables. Sub chassis can be levelled using plastic washers as shims above the primary suspension springs and their rubber bushes.
- As 1. But with a round tubular plastic arm
- As 2. But the orange light bulb at the front is replaced with a Red LED and one less wire is needed to provide power to the front light.
- As 3. But additions include no longer using a DIN socket as a junction, but has moulded turret tags at rear right of deck. Also suspension springs can be adjusted via screws from below. Improved grounding arrangements in arm pillar reduce hum using a staple shaped metal insert to ground the arm pillar through its horizontal bearing.
In addition to these , i have found some minor differences in the arm and spindle bearing arrangements. Some examples sit the bearing on a tiny blue metal disc, size a hole-punched chad and housed inside the base of the brass and black plastic bearing sleeve assembly, cleverly common to both arm and spindle . Others used a nylon disk, and others no disk at all. Blue metal disks in both bearings is best for ground continuity.
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| beneath the arm bearing (ignore roughly cut bitumen panels, non-standard) |
One example I had had a staple-like metal link inside the arm pillar to improve the grounding from the external arm pillar metal case, via the arm horizontal bearing to the sub-chassis.
As far as I'm aware the only difference between the NAD and Tesla models was the badge and maybe the colour of the paint used ? not sure if Tesla sold the deck under their brand before NAD got involved or after, I do know that if you attempt to clean the plastic upper chassis of a NAD unit with alcohol, the olive green paint comes off revealing a more metallic grey underneath. I wonder is this was the original Tesla colour, and NAD just resprayed them ?
There is another variant which was sold as the Lenco L800, which looks to be a flat arm unit except that the upper half of the plinth was made from wood rather than plastic. I've only seen pictures of this, never seen one, but would be tempted to get one.
Generally the decks hold their value well on eBay, perhaps partly due to the NAD brand, with the tubular arm models occurring more often than the flat arm. In the UK you can get an example for around £40-70 depending on condition. Indeed honest sellers often advertise them as non working due a number of common problems :
- Speed selector not working. The selector doesn't cleanly nudge the belt to the correct part of the motor pulley
- Automatic function doesn't work. The Deck has a simple auto raise and turn off feature at the end of a side, this seems to work on some decks and not on others. Its nicely done and doesn't appear to interfere with the functioning of the arm either way
- Motor randomly turns either way. This is sometimes due to a bad phase capacitor. If the deck always turns the wrong way or has trouble holding speed, it could be a bad motor winding.
What is inside ?
First disconnect from the power, and i mean disconnect at the wall, don't rely on the power switch at the front, as the motor is always partly live.
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| base unit (please note this example has additional damping applied , non-standard) |
So getting back to the run up to Christmas 2011, when i finally fitted the cartridge, aligned it, and tested it in secret, I had music through one channel and loud hum through the other. If this was to be a success , I needed to figure this out.
Despite the decks largely plastic construction,its well made, the plinth is in two sections , held by 3 Philips screws. I have taken my decks apart in excess of 20 times and not stripped any threads. I would say the plinth is less resonant than other plastic decks from Dual and various cheaper Japanese Direct Drive models.
So to open the deck up you first remove the lid, which slides out of the two rear hinges. The hinges pull out of their slots. Next you can remove the whole arm, it pulls away from the pillar at the point where it pivots. This requires some care , and if you have a stylus plastic guard or cover, its worth applying that first.
Next you can remove the mat which is rubber with an inner plastic insert which has one of those 45 adaptors for DJs in the middle. The mat is unusual in that its also substantially the platter. These mats often discolour becoming a snowy grey colour, but washing and cleaning with platanclene rubber restorer will bring them up like new. Beneath the rubber mat-platter is a simple pressed steel sup platter which has an upward facing lip which engages in a trough on the underside of the mat.
The painted steel sub-platter comes off revealing another sub-platter made of plastic which has the spindle passing through its centre. This looks similar to sub-platters found on Project and Rega decks. Between the two sub-platters sits a humble and unnoticed copper foil washer which helps to provide a ground between the steel plate and the spindle. You notice the paint is removed so the washer makes a good contact.
The plastic sub platter can be removed , the rubber belt fits around this. Pulling the sub platter out by the spindle reveals the main bearing, which is narrower than the spindle. Many decks these are the e same or larger diameter. As with everything you remove ,these pieces should be placed somewhere safe and ideally soft, as the main bearing should not be scratched or damaged.
Now you can remove the upper part of the plinth as you should be able to clearly see 3 Philips screws around the circular central recess. Once removed and safely stored,you have the problem of separating the upper half of the plinth from the lower. Gentle steady pressure with the fingers through the circular recess into the base i find works. Gently ease the top plinth away from the base. Eventually it should come free, and again place it somewhere safe.
At this point you should be looking at the black plastic base with all the wires , levers , springs and metal sub-chassis
At the back left you have the AC synchronous motor, held in place by two brackets which also act as guides for the speed selector contraption, lets call it a sled, as it slides. AC motors spin at a single speed, and the tiny aluminium spindle connected to the motor sets the platter speed. The belt is guided between two diameters of the pulley when changing speed, rather like the derail-er gears on a bike.
Centrally you have a metal sub-chassis which sits on 3 large springs via 3 rubber mounts. To the sub-chassis is attached all manner of bits, but the main things are the main bearing housing, that the spindle sits in, and the arm pillar, a fat circular metal tower on the right. It rotates with the arc of the arm, limited by a screw in a slot at its base. The sub-chassis normally 'floats' when the full platter system is present due to the compression of the springs. With the platter etc. Removed the springs force the sub-chassis up, but its limited by a locking wheel located beneath the deck. You can tighten this when shipping the deck to restrict the movement of the sub-chassis, loosen when its in its intended location.
There are two sets of wires in the deck. Power to the motor which is mains i.e dangerous , and signal wiring from the cartridge which are not dangerous. The mains cable enters at the rear of the deck and snakes around the partitioned wall to the motor, with further wires passing around the front of the deck to the switch at the front. Close to the motor is a silver phase reversing capacitor. Its function is to start the motor right direction as AC motors can turn either direction. A second suppression capacitor is located at the front by the mains switch and light bulb. The deck has no safety earth, but this is not uncommon and does not mean the deck is necessarily any more dangerous than any other household appliance, assuming its not been tampered with or modified.
The tiny thread-like wires emerge from the base of the arm pillar. These carry the signals from the cartridge via the arm. These wires are extremely delicate, as , by necessity, they are thick enough to carry the signal but thin enough to not impede the movement of the arm. These connect to the main signal wires either using a DIN socket as a junction, (no idea why ? Love to know, maybe for easy testing in the factory ?) or in later models via some solder tags moulded into the deck base. Conventional signal wires take up the audio story and snake around the back of the arm and snake around various partition mouldings in the outer wall of the base moulding.
A ground continuity wire also emerges at the same point from the deck, its anchored to one of the three screws at the base of the arm pillar. Its role is two fold, to ensure ground continuity from the deck to the preamp to avoid hum loops, and also to ensure electrostatic continuity from the spindle to a static point. Phono sections on amps usually have a binding post to attach this wire to.
There is a mechanical linkage from the front switch to the arm raiser and various springs and pulleys, some of which provide anti skate from the arm support arm, others provide the hit or miss auto raise function.
Now lets jump back to my sons deck. its now December and the big day is approaching and this deck is far from working. I have hum only on one channel . I decided that i must have an issue with the arm wiring, and gently tugging the coloured wires emerging from the base of the arm revealed that the blue one was not connected to anything.
I'm quite a practical person, and have some modest skill at soldering so I'm not too intimidated by these issues.
I realised that i needed to remove the arm pillar, and its held captive by a bolt in the curved slot at its base. Once this is removed you can carefully slide the whole arm pillar off its bearing. This reveals the same brass and black plastic bearing sleeve as the platter spindle uses. Neat, never seen this approach taken anywhere else. This is fiddly work as the heavy, substantially metal arm pillar is now only captive by 4 cotton thread-like wires, or in my case by only 3.
The wires solder to the base of the plastic socket the arm plugs into. The socket has two spikes which emerge from either side and sit in two cupped grub screws accessible from the outside of the arm pillar, forming the vertical needle bearings. Loosening the grub screws, only a little and the same amount on each side, eventually lets the socket piece loose of the top of the arm pillar and you can get at the solder tags on the base. However there is very little slack and these wires are hard to work with. I couldn't re-solder the blue wire and ended up making things worse.
In the end i decided to run 4 new wires from the socket base to new RCA sockets which id fit to the back of the turntable base. Trouble was which wires to use. In the end i used computer mouse wiring which is very thin but not too hard to work with. This worked but was still a bit stiff for my liking , causing i felt some tracking issues with the arm, so in the end i got some fine Litz wire from eBay especially for arm rewiring, which is finer. This is all very fiddly and i have to say that unless you have a specific issue with the arm wiring , id leave well alone as :
- The wires are fine and the soldering is hard. If you overheat the tags on the base of the arm socket you could deform it.
- Loosening and tightening the side grub screws for the needle bearings is hard to judge. Too tight and the arm doesn't move freely, to loose and there is arm play.
The only other thing i have done on some decks is to lubricate the motor bearing. Again i emphasise that these decks carry live voltage, so only attempt this if the deck is disconnected and you are sure you can safely work with such devices.
On two decks i had noisy motors. The motor is clamped in place but what appears to be a black plastic thrust bearing protrudes from the base of the motor and through a hole in the base of the deck. Several of the decks I've seen have had the black bearing cap mangled. I assume owners have either :
- Tried to remove the plastic cap with pliers. Don't , its doesn't come off from the bottom, you have to open the motor to get at it
- Forced the motor stator down to try and reduce speed changer noise and unwittingly popped the tiny thrust ball bearing out through a tear in the base.
The correct way to clean and re-lubricate the motor is to remove the motor from the base, by removing first removing the motor spindle which is held in place by a tiny diagonal grub screw from the top, then remove the speed selector frame and its guides. They are held in place by two screws which pass through tags on the sides of the motor. The wiring from the motor has some opaque silicone sleeves to protect it .
If you remove the motor, beneath is a small circle of yellow foam rubber which provides some modest decoupling of the motor from the base.mi have tried replacing this with sorbothane rubber and got much more noise, so stick with the original foam, but it might benefit from a wash in warm water And a gentle dry in the sun.
Once you have the motor out, still captive by its wiring you can obtain more slack by removing the clip-on black plastic box section which protects the motor wiring. With now adequate slack, if you examine the seam around the edge of the motor there are 3 small slots into which you can get the blade of a screw driver into. By gentle and progressive twisting action you can slowly prise the two clam shell halves apart. The trick is gently and do a small amount of twisting in each slot. Too much in one slot and you'll warp the motor shell. Gently and slowly is the trick. After a while the two parts separate and you can access the central stator, and pull it clear of the two halves.
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| sorry for the poor picture ! |
Putting it back together her is a case of reversing the process. The two sides will only go one way with the wires together. Once in position gently squeeze the two halved together with grips, gently and again, a little rotate, a little rotate, a bit more, till the two halves are tight together again. This motor self centres, so you should find it spins freely after this process.
Much of the above is explained in a video I made of the repair of a noisy NAD motor, including the disassemble of the deck
Much of the above is explained in a video I made of the repair of a noisy NAD motor, including the disassemble of the deck
Comments
I have just been given a 5120. The plastic sub platter is very stiff and really not happy to be rotated by hand. I tried pulling it up but I'm wary of how much force to apply. I know it was in storage for a while. Not sure how to proceed. Shall I just twiddle the platter round and see it it frees? Can't see any other way of getting under it. The sub platter is rotating on the spindle, should the spindle not rotate?
not sure if my comment got through
Hmm, well it sounds like the spindle is pretty stuck inside the bearing well. So I assume you have removed the mat, and the pressed steel outer platter and you are looking into the recess at the centre of the deck. there is a brown sub-platter with a metal spindle emerging from its centre. This sub-platter and spindle are bonded together and the sub-platter should not rotate around the spindle. The sub-platter and spindle should easily pull from the bearing as its not held captive normally.
If you screw the shipping dial underneath this anchors the sub-chassis, you should be able to grip the spindle and pull, perhaps with some pliers with some rag in the grip to avoid scratching the spindle.
Some old grease may have hardened in there.
Alternatively you could remove the whole subchassis and remove the bearing from beneath, but that’s a long and fiddly process and the deck has a number of small springs which tweak the position of the sub-chassis.
I You can actually remove the upper part of the plinth too, its held on with 3 screws, and can be removed with the sub-platter still in place. This way you might be able to get some freeing oil into that bearing from the side with a straw or metal rod.
I hope this helps.
It's a nicely engineered unit, a lot of thought went into its design.
I'll let you know how I get on and thanks for your help
If you are really bold, having removed the top plinth, also remove the arm, it pulls off at the pillar, using a 4 pin socket.
Now if you remove the Cir-clip on the locking wheel beneath, you can actually remove the whole subchassis. A few small guidance springs have to be carefully unhooked.
If you do this you can get at the 3 nuts under the subchasis which hold the main bearing carrier to the sub-chassis. NOTE this innovative deck, as you point out, uses the same carrier for the tonearm
Anyway you can loosen and remove the three nuts at which point the sub-platter, spindle and main bearing carrier should come away. The underside of the bearing is now open and you could get some penetrating oil in there. and hopefully get the spindle out.
A tiny clear plastic disc , size of a hole punched piece of paper , which sits in a recess formed where the brass tube doesnt go right down level with the sub platter in the plastic holder
OR similar but its a blue metal disk
OR nothing,mi.e the lower end of the spindle rotates directly against the sub chasis surface
Never seen a ball bearing and i wonder if someone has mistakenly put one in which has somehow jammed, or worse used something softer i.e a lead shot. Are you sure there is a ball bearing in there and its not just the lower tip of the spindle, remeber the diameter is narrower than the end of the spindle which goes through the centre of the LP.
By all means get in contact with me, im jives11 over at vinylyengine.com , if you message me there, happy to exchange pictures etc. I may have spare tiny disks and other parts.
The turntable nearly always starts when it's in 33rpm but can sometimes need a little nudge to get started, occasionally it starts in reverse. It is never able to start up in 45rpm, I always need to be in 33 then switch up to 45. Is this just a matter of replacing the phase capacitor, if so, what kind should I use?
The 'lift' function in the 'stop' mechanism does not lift, is there anyway to fix this?
There is a light ticking sound that comes from the turntable, as far as my ears can tell, it's not being picked up by the stylus. Is the motor on it's way out do you think?
Hope you can help ;-)
thank you for your kind words. You got a bargain for £7 !, the hinges alone on ebay can go for £20 as they are the same as the Linn Sondek hinges which seem to be in demand. The arm too will fetch at least £10, so no matter what happens with this deck, you are in profit I reckon.
The reverse direction is a symptom of the phase cap needing replacing which is a 250v 0.22 Polypropelene or polycarbonate axial capacitor. Maplin sell the correct value in the UK. Its a soldering job, you need to disconnect the deck from the mains, remove the arm (it unplugs at its vertical bearing), the lid and unscrew the three screws that hold the top of the plinth on. My blog has now a link to a video I did on servicing the motor and this has a lot on dismantling. The phase cap is on the left hand of the deck where the motor wires solder to some fairly ugly contact points. I don't know if you are happy soldering ?
if you have access to a a mutlimeter it may be worth desoldering the motor wires at the same junction and measuring continuity (resistance) across the 4 wires from the motor. There should be two separate circuits through the motor wiring i.e you should have continuity between two pairs of wires. if you dont have that , you have a break in the wire for one coil and the motor is half dead.
I've worked on 7 of these decks and not had a dead motor yet, but it can happen. if the coils are good, it may be worth watching my video which shows how to clean and relube the motor and get it back to smooth operation.
The motor always spins at a constant speed set by the mains frequency, 33 and 45 are simply blet positions on different radius sections on the motor pulley, and the speed changer is a bit of problem. Removing the platter will show you the motor, but it's hard to see how the belt sits, as the weight of the platter holds the sub-chassis down. If you are safe around live mains, it can be insightful to remove the top half of the plinth, then put rest of the deck back together, you can then see how the sled works with the platter in place and with the motor running. HOWEVER THIS IS DANGEROUS, as the mains wiring where the motor wires connect is exposed, so please be careful if you decide to do this, keep hands and tools well away.
the ticking, is that present with the platter removed, , then try with the belt removed ? it could be just dirt in the motor, so the video might help.
Did you replace the ortofon cartridge or just the stylus ? the arm can be used with other cartridges, and with the damping adjustment, theoretically it could be used with an extremely wide range of compliances.
I would also suggest posting in the vinyl engine forum . google vinyl engine and join the forum. I frequent it most days, and there are a lot of very friendly and expert fixers in there.
Good luck and maybe see you in the forum or please feel free to post here more Questions or your results
Yes, I just replaced the stylus, not the whole cartridge.
I'm fairly handy with the soldering iron so will give that a go. I've a multi-meter as well so will test for continuity.
I've not tested the ticking with the platter or belt removed, I'll try that. If the ticking persists with no platter/belt, would that indicate a faulty motor?
I dont think that ticking is necessarily an indication of a failed or failing motor, it could just be some dirt or hardened grease in the motors thrust bearing which acts like a tiny cam and raises and drops the motor spindle every revolution.
The thrust bearing on that motor sometimes gets abused. It's visible beneath the deck, and some times decks have been abused where the motor has had a heavy downforce by owners frustrated at the speed selector sled not working. Also I have read of people cutting the plastic cap to get oil in, which is a mistake as there is a tiny ball bearing in there which will get lost or shifted off centre, so its possible that the motor is not turning on a a lubricated point on a ball bearing. How does the plastic cap on the underside of the motor look, you can see it from beneath as it sits in an exposed hole ?
The plastic sub platter also has a peg which is used by the auto-raise at the end of the side, it might be the cause. it also could be the belt rubbing in a very localised spot.
also well done on repairing the deck. The motor dismantle is not so hard but I understand. if the ticking is not really audible then I'd leave. When you said you removed the platter, did that include the plastic sub-platter with the spindle through it ? I ask as this has a peg beneath which catches the auto-raise mechanism. removing just the belt is another ay to isolate wether the issue is your motor
BTW assume your a fan of either Heart of Darkness or Alien, or both
I took off the sub platter and belt. It was noticeably quieter and I touched the plastic surround to see if I could feel vibrations; nothing. Will report back when I give it a go. Would you recommend I stick with isopropyl or could I use a bicycle degreaser to get bearings clean?
Degreasing the bearing needs to be done with a method that leaves no residue, so I favour Isopropyl Alcohol and cotton buds. > How you clean the bearing itself doesnt matter, as its easy to wipe clean any excess, but the brass sleeve that it descends into is better done with a solvent that dries clean.
Anyone any idea what fluid to fill the glass damping fluid 'bottle' with?
My deck is as good as new as it's been sat in the loft for around 20 years. However most of the fluid seems to have either evaporated or leaked.
Thanks
http://demonpowerproducts.co.uk/images/359396.jpg
Here is my page:
http://nad-5120.blogspot.hu/
Oh, Jesus...
Now i see your question from 2013...
Sorry...
I'm working not too much on this blogspot-page. :-)
My answer:
Most likely lead over the 3,3nF 400V capacitor, which is connected in parallel with the switch. The replacement will usually solve the problem.
Greatings:
George Cserkuti
I appreciate your kind words , it seems these decks were most popular in CZ, HU and UK, and their value seems to be going up second hand.
I still want to find a Lenco L-800 version with the wooden top plinth, to complete my collection
The screw is a slot head (not a philips) and require a very fine screw driver. In the UK these are called "watchmakers screwdrivers" as the screw heads are very small i.e. as found in watches. However there is sometimes a small amount of enamel to prevent access to the screw head, and you need to scrape this out first. Do you have a very fine screw driver i.e 1mm wide ?
http://i47.tinypic.com/fa4dno.jpg
the damper fluid I used was 100,000 cst silicone oil. It is sold for Radio Control Car shock absorbers, if you google search for 100000cst you will find sellers who stock it.
the small clear plastic reservoir for the oil sometimes comes off, I think it is held on with glue. It is easier to refill by removing it, then reattach with a single small drop of super glue. If it does not come off you need to dismantle the arm, remove the balance adjustment which hold the rod which extends into the oil. Then you have to refill the oil chamber through the hole. This is quite a slow job as this oil moves very very slowly.
Cheer, Mike.
Cheer, Mike.
Cheer, Mike.
yes - getting the belt to stay on can be frustrating.
a few things to check.
1) ensure the belt is very clean and dry. I tend to run the belt through a kitchen towel with some alcohol (Isoprpyl) or Platenclene rubber restorer, sprayed on it. Also make sure the outer rim of the subplatter is also very clean , as is the motor pulley
2) When you put the belt on you have to take most of the weight (mat, aluminium sub-plate and plastic inner adapter) off the platter and the suspended subchassis. Added to this weight is the weight of the record, which can be up to 200g. Hence the relative height of the sub-platter to the motor pulley changes a lot AFTER you have put the belt on. I tend to put the belt low on the sub-chassis, such that as that sinks , and the motor engages it will work its way up to the middle
3) Its possible that the pulley on the motor has dropped. It should be adjustable via a grub screw at an angle on the aluminium top. However the screw holes were filled with enamel paint. If its ever been adjusted the paint will be gone, it might be that the pulley has been dropped or that the motor has dropped. Sometimes owners get frustrated with the erratic speed change and push the pulley down which stresses the lower thrust bearing. Basically the whole motor might be sitting a tad lower than ideal.
4) The best way to diagnose what is going on is to run the deck "naked", i.e remove the top plinth and reassemble. An oddity of this deck is it runs fine with the whole upper plinth removed. basically follow the video I do, but put the arm back with the plinth and lid completely removed. You have a naked NAD !
However there is a risk as this exposes LIVE electrical wiring, so only do this as a last resort , away from children , and ideally on a bench . The wiring close to the left hand side near the motor junction is most exposed. I place my left hand behind my back, and I only advocate this as a last resort. as if you run the deck (It doesn't need to produce sound, this is just a functional test) you can see exactly what is going on from the side with the platter , mat and a record in place
First of all. Thanks for post. Its really good!
I recently got hold on a NAD 5120 and I what to fix the tonearm auto raise.
Mostly out of pure lazyness. You listen to a record while fixing other stuff and I dont want the needle end up spinning for 10 min. or more before I get back to it.
Have anybody found a guide, know the magic words or have a picture of a working auto raise?
when I opened mine it look pretty much like picture 17.
Thanks in advance and I hope all are enjoying some good music.
I have had one deck where this worked and one where it didn't. Its a strange contraption BUT I think the most important thing is that there is a plastic peg on the underside of the plastic sub-platter. This peg engages with the internal rod which has a V shaped metal cutout on the end. Remove the platter then the plastic sub-platter and look on the underside for a plastic peg
I think the system is to turn the power off and that will engage the lifting mechanism via the power shaft. So beside a pretty difficult job of setting up the tone arm, one has the extra job of setting up the lifting mechanism also...
As I can see that most of the system broken (both pin and lifting shaft) I think I will leave as is. It was properly done for a reason…
But thanks for your help. I will get back with a replay if I find a proper solution.
But thanks for the offer on the sub-platter. I will leave it as I said.
Have a good one and thanks again.
I can't see that anyone has actually tried this yet but I just took a punt on the Debut Carbon 230V motor to replace my well and truly ruined (bearing shot) NAD5120 motor and I am pleased to say that they are a definite drop-in replacement as long as you have some - rudimentary - soldering skills. The wires are the same colours so it's almost idiot-proof.
I bought the motor from the very helpful Henley Designs - they even got one out of a box and checked some measurements for me before I committed to buying. Just make sure you get the type M307 230v version. Cost 40 GBP plus postage.
Hope this helps someone who needs a new motor and can't find a donor turntable.
Thanks for posting
I did have one but I removed it and cannot now find it, I think I perhaps gave it to someone to complete another NAD. I found that the metal of the lift (I think it was aluminium) is very close to the copper tracks on the flat arm. These are used as the arm wiring, and the finger lift seemed to cause some electrical hum as I think it introduced a ground loop.
I also did not like it as I think it is best that the cartridge sits firmly against the headshell or arm, with the maximum surface at the top of the cartridge contacting the maximum area on the bottom of the flat arm. The finger lift reduces the contact are as it is between the cartridge and the arm.
I think it is possible that the designer did not intend to have a finger lift and this is why there is an area of white dots on the top of the arm to indicate where you can hold the arm ?
I do have a metal finger lift that is from a separate headshell and I would be very happy to send it to you for free, it is just sitting in a box of bolts and screws and other turntable 'treasure' ;) . Its not the original NAD but it will work I think. My email is jonathan.ives@gmail.com, if you want to send me your address ?
Cordiali saluti
Jonathan
Thank you so much Mr. Ives for your help and for your blog and best wishes for you and your family.
Tommaso Miraglia
Could this be caused by the capacitors? Also a later thought is maybe it is caused by the mains lead is plugged in the wrong way as it uses a two pin plug.
Any advice would be appreciated
Could this be caused by the capacitors? Also a later thought is maybe it is caused by the mains lead is plugged in the wrong way as it uses a two pin plug.
Any advice would be appreciated
when you say static, could you clarify what you mean ? Do you mean a crackle, a hum or a sharp discharge, like a spark ?
The capacitors will not make any difference IMHO. One is to set the direction that the motor turns, the other does suppress noise but only for the front switch, it suppresses any slight arcing on the contacts when turned on or off.
the mains connector will not make any difference either /
Do you have the ground wire connected to your amplifier. This is a third thin black wire which exits the deck with the left and right signal wires. Also of you remove the matt and metal sub platter , there should be a copper washer-type device fixed to the spindle. It's purpose is to ensure ground continuity between the metal spindle and the metal plate sub-chassis. Sometimes these get lost
These decks can have issues with hum, their signal grounding is a bit hit and miss in places especially on the original flat arm/orange light decks. It was improved on the later round arm/red light models. I also think that the flat arm model probably should not have a metal finger lift as this comes quite close to shorting the two signal grounds. From the pattern of dots on the arm back, I think it may have been a later and unnecessary compromise.
I am a bit busy sorting out some speaker issues, but if I can I will create a video explaining how to setup the deck. Setting up the tonearm is entirely about the physical aspects of the cartridge , alignment, tracking weight, and the damping aspects, its not about the electrical side, So if there is no signal or the signal is low, this is not resolvable by arm configuration, unless the arm is not seated on the pillar and no signal is getting through. Tracking issues are resolvable by setting the various arm parameters
The Ortofon X1-MC should work fine into the phono input on the Amp and set to the Moving Magnets setting on amps where this is selectable.
So is the problem that you are getting no signal or that the arm will not track a record correctly (skipping, distorted sound) ?
The problem is distorted muffled sound and a lot of hum through the speakers. The TT is also very loud though the amp even though the amp is barely turned up.
I currently have two of these TT, one red light model and one orange. Have tried the cart on both TT and both tone arms and have the same issue. I have try my MM ortofon 5E cart on both TT and it works fine.
The amp itself doesn't have selectable setting on the phono stage.
Hum from turntables can be caused by multiple issues, including ground loops, the motor magnetic field being picked up by the cartridge and mechanical hum from the motor entering the replay system and being picked up by the cartridge. Mechanical hum issues are not common with this deck, but various ground loop issues are, especially with the older Orange light/Flat arm unit, which does not have very good electrical continuity between all the metal parts and hence via the ground wire.
Oddest symptom is that the X1-MC should be so loud. the only HOMC I have ever used is the Denon DL110 though not on a 5120. Its output was comparable with a MM but was on the quiet side ? And this is going into a Phono input on the namd set to MM (or defaulting to MM, I dont recall if the 3020 had a MC option )
Are you able to try the X1-MC in another deck ? Could it be damaged ?
The OM's seem to work well in these and though expensive, I found the OM20 stylus (STY20) sounds wonderful
I will try it on my sister turntable and see how it goes on there. The cart doesn't looked damaged. the reason I bought the second NAD TT was for the cart as I wanted to try a MC cart. Now it seems more trouble than its worth.
The auto-lift mechanism resembles Waddingtons mouse trap, but is triggered by a peg on the underside of the subplatter engaging with an aluminium and plastic arm with a notch in the end. I cant say I know any adjustment.
What you can do is remove the top half of the plinth (see youtube video on nad5120 noisy motor ) and put the platter and arm back. The deck will run in this naked form, which is dangerous as the electrical wiring is exposed BUT you can see what is going on. You could probably diagnose the problem with out power, simply hand cracking the platter and arm
The motor has been working great since you last helped me (5 yrs ago!). The thrust bearing is still there, the cap is intact but is maybe a little bulged. I'll try and post a pic. My set screw on the pulley is dead and the pulley sits a fraction higher than flush with the spindle, not sure if that is the cause.
Pic from under the deck.
Hmm, interesting. Well first off, mats are not the answer. This deck was designed such that the platter is the mat and the mat is the platter, and any other arrangement will unbalance the suspension. Also the shipping dial beneath should be slackened as far as it will go allowing the deck to float on its 3 springs.
You mention you set the tracking weight, so there are a couple of ways of doing this:
1) With scales, either old style stylus scales or those cheap digital scales that you can get very cheap
2) adjust the balance weight by turning the dial until the arm is in the null position where it floats , neither tipping or dropping. turn the inner disc inside the wheel with a screwdriver so 0 is at the arrow, then rotate the whole dial until you get the desired tracking weight. the anti skate which is the arm rest should be set to the same value as the tracking weight, though I favout a little less, so say 1.5g tracking weight is 1g of anti skate.
When the arm is above a track and you flip the switch at the front, the arms descent is handled by a damped piston which should have a rubber bead on the tip. This should stop the arm from moving until its landed in the groove and the lowering piston is clear.
I think a few pictures would help diagnose this, if you could take a few of the deck and the arm while in use it would help. my email is jonathan.ives@gmail.com or there is a facebook group dedicated to the NAD 5120
https://www.facebook.com/groups/237444080537190
Yes, without the the entire platter and mat assembly there is no initial startup jolt all moving the arm when in place and descending properly in position. Just putting the metal plate on there also still there is no initial jolt and all is well. Once I place the heavy mat on there to weigh down the platter assembly.....once turned on and the tone arm set at the wanted position, turning on the unit, now there is the initial jolt which moves the arm away from the wanted position. After the jolt, the arm still slowly descends correctly, but not in the wanted position.
Also yes I have used a tonearm pressure gauge to set my tracking
The tone arm does descend slowly and fine after the initial start up jolt. Just like urrrrrgh on why it is doing that.
OK the metal platter has a lip which turns up and engages with the groove around the mat. i reckon you probably have that but worth checking .
if you remove the platter and remove the belt, put everything back except the belt. Then spin the platter by hand, one swipes of the hand. How long does it spin for ?
I think I need some pictures (email in previous reply)
I put the old belt beck on and no jolt or pull on the chassis with the mat and platter on when it is first turned on. Much quieter too.
I put both belts side by side and the new belt is clearly about a half an inch shorter. The old belt is 9.5 inches and the new one is about 9 inches I got the new belt off of Ebay. That does seem a bit short, or is it not?
So my question now is where do I find a place that sells the right belt for my new used beloved 5120?
Thank you again for your time and help. \o/
belts - well as you discovered not all belts are created equal. My goto place for belts for this and other decks was William thakker in Germany :
https://www.thakker.eu/en/belts/turntables/nad-5120-original-thakker-belt/a-3224
However last time I looked they'd stopped shipping to either UK or USA (I'm UK) Worth checking again.
I reckon that lpgear.com are the closest thing to Thakker in the USA. I cannot vouch for their belt, but I'm sure they would be able to supply the dimensions to you
https://www.lpgear.com/product/NADB5120.html
It's probably worth cleaning the old belt, and the surfaces it's in contact with, especially the outer rim of the brown plastic sub-platter and the motor pulley. Rub both with some Isopropyl alcohol to remove any slight grease. The Belt is probably best cleaned simply pulled through a cloth. There are rubber restorers, and Platanclene for print rollers is very good. Squirt on a cloth and pull the belt through.
Speed change on this deck can be problematic. Its an AC synchronous motor which means the motor always spins at the same speed determined by the mains frequency (50Hz Europe, EMEA and Asia, 60Hz USA and parts of Japan). The pulley ratio to the sub-platter size determines 33 or 45. hence the belt has to be flipped between two pulley diameters, like the gears on a bicycle. Sometimes you need to adjust the metal sled affair which nudges the belt. Slackening the two screws either side , wiggling it and retightening can help. not very scientific, but its all about small tolerances.
So went with LPGear for a total of 24 dollars all together.
Will be returning the other belt for 13 so no biggy
Hmmmmm, adjust the sled you say? You mean the 2 metal screws on the black base, correct? Will give that a try.
I did already rub down the pulley and sub platter, with Isopropyl will try a rubber restorer tooo.
Thank You again and will keep you posted.