The Lenco thread on Audiogon has alas been stopped by the moderator. Lenco thread nr.2 is already in the air! It opened with a copy of my Lenco TDL with added copied comments by Canadian Jean Nantais (J.N.) who started the original thread, and other experienced Lenco rebuilders. This is a revised version of that by yours truly. Get a mug of coffee and read it all the way through before you get to work. Better still, print it out and keep it at hand. You don't have to go all the way, you can start with the simple recipe at the start of each point. The more experienced DIY-ers amongst you can follow JN all the way to sonic Nirvana ;-) Usual disclaimer: "The management won´t be held responsible...", etc. But DO try this at home!
1. Take your Lenco apart, take the chassis off the plinth, remove the springs. Some people tweak the L75/78 arm, see here. If you don't want to do this remove the tonearm. If your new tonearm has its own armlift, remove the Lenco armlift as well. Same for the arm rest. IMHO the original Lenco arm is not worth putting time and effort into but YMMV etc.
Comments:
"I first listened to my first Lenco for a few months sitting up on metal stilts with no plinth, with a Rega mounted in the original tonearm hole. It utterly blew me away. If you like the original plinth, then remove the bottom, get rid of the springs, put some sort of feet on the corners to lift the edge off the shelf, and screw the Lenco down solidly to the original plinth. This will approximate bricks."
2. Take out the main bearing by removing the 3 screws around it, unscrew the little security screw at the side of the bearing house and take out the bearing. Take care not to loose the little ball at the bottom. Clean it and put some new fat/grease on it. (See pics) If you want to use oil you'll have to make a better cover underneath the bearing.
Comments:
"For lubricant, I polish the bearing proper with metal polish, making sure all vestiges of older lubricant are washed away, I wash out the sleeve with engine cleaner (mineral spirits are good too) and make sure all is clean and dry, and then top up with Mobil 1 synthetic oil (or other synthetic), and find the platter can easily spin for close to a minute and a half (sometimes two) with but a push!" JN likes a metal polisher called Cameo, if you can't get it use
a substitute with sulfamic acid and surfactant.
3. The simple recipe. Remove the 4 screws at the back of the motor and gently pull the back out. The motor axis turns on 2 little spindles, 1 at the front and 1 at the back, in little bronze bushings. Clean the bushings from the inside with a rolled up paper handkerchief with alcohol. Clean and relube the spindles. Carefully reassemble the motor. Clean the big spindle with a paper towel and alcohol.(See bornin50´s site) Bornin50 took the whole motor assembly apart. He reports that you can adjust the front "nose"bearing of the motor spindle for minimum motor noise/vibration. I haven't tried this.
Comments:
: " Cleaning and optimizing the motor was as effective in increasing clarity and focus as marrying the plinth to the top-plate. I would consider this mandatory, and it has no negatives and causes no shifts in balance. To do this you have to go all the way, even if it means buying a fairly expensive tool ($15-$20 US) for only this job: Snap Ring Pliers, to remove the snap ring which holds the workings in place at the nose of the motor. [You can also use small needle nose pliers] When disassembling the works at either end, keep a piece of paper handy and make a diagram of how the workings go, in what order and what orientation. At both ends of the motor casing there are brass balls drilled through to make the bearing bushing: I used a piece of string soaked in solvent (paint thinner, motor cleaner, etc.) to remove any baked-on grease from the inside of the little bushings, and then ran dry string to remove what was left. I re-packed the workings with new grease (molybdenum or Mobil 1, placed wherever metal meets metal, and packing all empty spaces to damp resonances, even of the springs), after cleaning them in solvent (the springs, brass discs, etc.). At the nose end there is a screw which must be screwed in just so to reduce noise. Its secret is that inside the hollow screw is a little metal piece which is spring-loaded to absorb and kill off vibration of the motor spindle: it is a good idea to remove the tiny little pieces (keep a bowl nearby!) and clean them also in solvent, and clean the inside of the hollow screw using a piece of string. Rig the motor so it is running (place a jumper at the switch terminals, 2 and 3 where the white motor windings are attached on the barrier strip on the motor casing, and run an AC cord to the wall to positions 1 and 4, waiting until it is screwed into the terminal before plugging it in!) and sitting on a hard block of wood so you can hear the buzzing (louder or quieter), and screw the little nose screw in until the motor is actually whining against it making noise, then back off until it reaches the first silent point. Use the attached nut to lock it in place, you'll probably have to do it a few times to get it right, be patient."
"Finally, adjusting the motor core does work, there is an optimum position for the intrepid. Like Ronnie I first did this while it was plugged in, but when I became plugged in too (ouch) I ceased doing it this way and adjusted, re-assembled and plugged it in, took it apart adjusted again, reassembled and plugged it in, until I got the quietest point. To do this undo the motor casing via the four screws and take the ass end in hand. You will see four screws holding the motor core in which the motor spindle spins. You could simply tighten them down (they are likely loose) for quieter operation, or you could be daring (or mad) and undo them and play the re-position game until you reach the quietest orientation [moving the motor core so that the armature is centered should get you close]. Doing all these things results in a large improvement in sound quality, with no penalties. At the very least the flushing and fresh grease, re-adjusting the nose-screw, and tightening the core screws, is mandatory! BIG improvement!"
4. Put a drop of oil on the idler wheel spindle, or take the spindle apart, clean and relube it. Don´t put fat, grease or oil on the rubber of the idler wheel. Don´t touch the rubber with your fingers. Get a Lenco with a metal idler wheel. I have one with a plastic wheel, it´s not straight and makes a lot of noise. I have found places on the Web where you can send your idler wheel to to have it refurbished like Svalander in Sweden.
Comments:
"For the wheel, I similarly clean the bearings, and even soak a piece of string with engine cleaner and clean out the inside of the bushing on the wheel itself, clean both teflon washers, dry everything off, put some Mobil 1 grease on both sides of washer #1 and slide it on, then Mobil 1 oil on the spindle and mount the wheel, then put grease again on both sides of the other washer, slide it on, and fasten it all with the little clip (be careful not to lose the clip, sometimes it goes flying!). You want just enough play the wheel spins freely, not a micron more. And be careful with the idler-wheel arm, it is quite easily bent, as I just discovered to my astonishment, do not apply any pressure to it, proper geometry of the wheel and performance depends on it. Make sure the sliding post where the idler-wheel attaches is well damped with grease, above and underneath, to prevent ringing. Slather the slider where it moves in the top plate track with grease or Vaseline.
Damp the idler wheel arm with Teflon tape or plumber’s miracle tape. Make sure the idler wheel runs very close to parallel to the outer circumference of the platter."
5. Damp the chassis from the underside with whatever suits your taste. J.N. uses Dynamat with good results. Steve from the ultimate Thorens site The Analog Department does the same. Dynamat is expensive though, i use a kind of self adhesive bituminous tape.
Comments:
"Judiciously apply some damping sheet of some sort to the underside (and I mean judiciously, don't damp the ever-loving crap out of it and kill the goose that laid the golden ultra-dynamic, ultra musical eggs)."
6. Replace the spring which pulls the idler wheel against the motor spindle with some elastic. See pic. I wound some bitumen tape around the idler wheel rod. You can feel it vibrating when you put your finger on it during play, with the platter off.(See top pic)
7. You can replace the power cord with a better, shielded one with a better plug. I haven´t done this (yet) so i can´t commend on the improvement you can make here. Jean Nantais warns against heavy power cords hanging from the motor suspension and thus preventing it from moving freely.
Comments:
: “I removed the rather large wire running from the switch (of the L75) to the motor, and replaced it with tiny 24-ga. solid-core to prevent this as a route of vibration from the motor to the top-plate and platter. I also placed some Dynamat where the wire solders to the electrical switch to prevent the wire touching the metal top-plate, stopping this contact point.” "Use 20 G solid core between motor and AC. Bolt the 20 G to the plinth using some Sorbothane around the wire at the cable retainer to stop vibration from the motor going anywhere by this route. Grease the on-off switch links where they touch the top-plate to prevent rattle."
8. I put some electrician´s tape around the armtube of the Decca tonearm you see on the photo above. It helps to dampen some vibrations in the armtube. Jean Nantais rewired the Decca and contact cemented some parts together like the headshell to the armtube. As JN reported in the Audiogon thread a Decca rewire job is not for the faint hearted, i haven´t tried it.
9. About changing the arm. There are 2 problems:
A. The replacement arm is longer than the original Lenco arm so the spindle to pivot distance is longer. Prime example: Rega RB250/300, 222 mm instead of 212 for the original. See Blueintheface´s handy table of arms, remember though effective arm length and pivot to spindle distance are not the same...
Comments:
Let's just say JN LIKES his Lenco/RB300/DL103 combo...
B. VTA is off, the arm is bum up so to speak.
Solutions for A,B or both:
9.1 (AB)Rotate the Lenco chassis a quarter turn and make an armboard next to the chassis. Added bonus: the arm doesn´t rest on the vibrating Lenco chassis anymore, but on the big plinth. The most elegant solution IMHO, i haven't done this so now i face the choice of having to make an entire new plinth or cut up my plinth and a Lenco... Better do it right the first time around! You can make a 3 armed monster by making 2 arm boards next to the chassis and mounting a Decca arm in the existing hole! The light platter Lencos have the advantage of having a smaller chassis so this trick works better. And of course there are the hard to find motor units the 88 and 99.
9.2 (B) Add an extra thick mat on top of the original Lenco mat. This changes the sound however.
9.3 (A) Enlarge the existing arm hole in the chassis. A lot of work and it doesn't solve problem B.
9.4 (B) In case of the Decca International, mount the mounting ring underneath the chassis. So you can push the arm pillar further down.
9.5 (B) Mount a shim between the headshell and the cartridge. Not my favourite but YMMV etc.
9.6 (AB) Saw off the upper right corner of the chassis and make an armboard IN the plinth. (See Willbewill´s 2nd creation) Added bonus: the arm doesn´t rest on the vibrating Lenco chassis anymore, but on the big plinth. JN's fave armboard material is maple. Steve aka user501 of The Analog Dept. uses a kind of phenol resin.
10. Glue the Lenco rubber mat onto the platter. Cheap and easy mod. Gets you more clarity and detail.
Comments:
"Clean the mat with Rubber Renue. Glue the Lenco rubber mat onto the platter using 3M 77 spray can contact adhesive.
An alternative is Herbie’s Way Cool mat at $50, recommended by Dave Pogue and Albert Porter"
11. Make a BIG plinth for your Lenco and bolt the chassis onto it using the 4 threads from the underside. So NO springs, rubbers or whatever. I used 6 layers of birch multiply and MDF glued together under pressure. So NO solid MDF. Most Lenco modders use layers of different materials to get effective resonance damping. You have to cut out the shape in every layer you need to make room for the chassis. Leave some room underneath the tonearm and around the motor. Leave the space for the arm board. The motor must swing freely in its suspension and it gets hot after a while. Otherwise make the plinth as tight and massive as possible without resonating chambers in it. (See Willbewill´s plinth) This is the most important mod. For a couple of tenners in materials and a lot of B,S&T you can make a lot of improvement here. Both in term of reduced rumble/noise and improved sound.
I made a "simple" plinth, the Lenco touches it only at the edges of the chassis. JN has moved on to a Direct Coupling approach where the plinth makes maximum contact with the chassis for improved resonance damping. See the links section below for some plinth examples. JN has repeatedly advocated the use of a mix of MDF and birch ply. Jean Nantais’ formula uses ½” MDF top layer, ¾” birch ply second layer with 1/8” neoprene rubber gasket between bottom of the top-plate in contact with the birch-ply layer (Direct Coupling). Bolt the Lenco by the 4 top bolts, plus three screws at 3 different points/neoprene gaskets between round part of top plate and birch-ply layer. Below that alternate ¾” MDF and ¾” birch-ply. JN says the bigger&badder the plinth the better! Mass is class!
For armboard materials, JN writes: “I personally love the sound of maple as a tonearm board (sweet and open!), and purpleheart was good too. No experience of any other hardwoods. Obviously, mahogany sounds great, as the Grado Woodies demonstrate."
12. Placement is important. If you have a springy wooden floor, if you can get the Lenco on a solid wall shelf do it. I placed my L78 on rubber pods at first, changed to aluminium cones/dishes now, way better soundstage and depth. Do a search on the Vinyl Asylum on the subject of TT placement, you see TT on sand boxes, inner car tyres, simple wall shelfs, butcher blocks, huge blocks of concrete etc. Spikes, cones, footers. Find out what works for you, this is simple and cheap DIY.
13. I cleaned the underside of the platter with a paper towel and alcohol. Take your time to let the alcohol evaporate, alcohol eats rubber. A clean platter gives the idler wheel a better grip.
14. Ground the chassis of the Lenco by connecting it with a ground wire to the ground post on your preamp together with the ground wire of the tonearm. This should get rid of the hum.
15. Some people remove the aluminium plate on top of the Lenco chassis in order to paint the chassis.
Comments:
"The aluminum plate that covers half of the metal plate can be removed if desired. This is done by using a heat gun or hair dryer. Take your time and the aluminum can be removed without destroying the nice grey paint underneath. Once removed, the rubber glue can just be pealed off and automobile wax can be used to restore its hidden beauty. An extremely important note here: If the aluminum plate is removed, one loses the protective plate that covers the paint and metal where the speed lever touches the metal. One must be very careful not to let the level rest against the metal when adjusting speed. If care is not taken, the lever will scrap off the grey paint exposing raw metal. This should not be an issue since the outstanding Lenco motor once cleaned and re-lubed is incredibly stable and one will not have to constantly adjust speed once it is set.
Another point that needs to be addressed: the brass circular housing that holds the on/off switch is held in place by a small square piece of metal. It must be removed to completely remove the aluminum top plate. One must take their time when prying off this square holder. It must be reused to secure the brass housing when putting the switch back in place. Take your time when reinstalling this piece of metal. You will need some elbow grease and a flat head screw driver to set it properly. If not reinstalled correctly, your switch will begin to wobble over time and the entire table will have to be disassembled to fix it properly."
An interesting concept by a fellow Dutchman, "Reinderspeter" on the Lenco Lovers forum. A DIY top plate to replace the Lenco chassis altogether. I haven't seen it in the flesh yet. The first batch he made is sold out but he may make another batch.
Pros: thicker than the original, less vibrant, flat so it makes 100% contact with your pile of birch ply/MDF. The motor is mounted on a separate part of the plate (no direct contact with the rest). All kinds of tone arms are mountable, 2 of them in fact. The platter is more elevated from the top plate so to speak so correct VTA is easier to achieve. And it doesn't HAVE to be green ;-)
Cons: speed switching is limited to 33/45 and less user friendly. You have to take off the motor, bearing etc. from the Lenco chassis and mount it to the new top plate. You have to make an electrical on/off switch for the motor. The idler wheel doesn't come off the spindle when the TT is not in use. Yes. Suppose you use your Lenco 1 hour a day. Then the idler wheel sits against the spindle motionless for 23 hours each day. Mmm. Last but not least: it doesn't look like a Lenco anymore!
Freek´s very own Lenco L78 creation.
The Audiogon Lenco thread. Nr.2. The Lenco Army marches on!
The Decca International NOS Tonearm, alas SOLD OUT at Ah! (Holland)
Walrus UK may still have a few of them!
A review of the Decca arm, sent to me by a fellow Dutch vinylbuff, thanks Jan! (JPG, 286 Kb)
Willbewill´s Lenco plinths.
A brief history of Lenco TT.
Bornin50´s informational Lenco site.
Bornin50´s 2nd Lenco site...
Stefano Pasini´s Lenco page. Also stuff on Thorens, EMT...
Tom mcQuiggan´s new Lenco site, looks promising!
A nice L75/S , lots of pics, i would like to hear this arm
Vinyl Engine, I'm not worthy, what a wealth of info
Albert Porter´s stunning maple L75.
Ronnie Ericsson´s stylish "design" white L75.
4yanx's creations: 1 2 3 4 5 6 1a 2a 1b
Reinderspeter 's creation with DIY Ladegaard tangential arm!
Vint_age 's super heavy 3 part Lenco plinth.
John Nantais, our Guru's Audiogon system page.
Gilbodavid sold his 401 for a Lenco!
Bennymus ' L78. He modded the original Lenco arm. Mmm maybe worth a try...
Lenco L75 rebuild with a DIY Schroeder arm, nice site, lots of pics
Islandflyfisher 's big black L75.
Kim Gibbens' gorgeous L75 plinth.