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[Italian version here]
Product name: Linn Akito Tonearm (Rebuild)
Manufacturer: not for sale, TNT-Audio DIY project
Author: Roger McCuaig - TNT Canada
Published: May, 2021
Over the years I have purchased a lot of used audio equipment via the internet and I would say that I have been pretty lucky at it. Very rarely have I regretted my purchase and for the most part, I received what I expected or at least something close enough that I couldn't complain. Well recently my luck ran out. I bought a Linn Akito tonearm, in a rush, without doing enough research and ended up with problems. If I had researched this item properly, I would have learned, as it appears to be quite common knowledge, that the first generation Akito is notorious for having bad bearings as well as problems with cracking of the plastic cueing platform.
Well, the Akito that I bought, not even knowing that it was a first-generation model, had both of these problems. The vertical bearings might have been good enough to use but the horizontal bearings definitely had some stickiness. As for the platform, well I'm not sure what effect the crack was having on the arm's performance but it sure wasn't helping. I only put this arm into service a couple of months after receiving it and it actually worked OK for a couple of weeks. Eventually it started skipping and jumping right out of the track. When it got near the end of the record, lifting the arm up with the cueing lever would result in the arm flying backwards (towards the outer track) by about 1 1/2 inches! As if the antiskating spring was getting would up. I took the antiskating mechanism apart several times and couldn't really see any problem there. So, in the end it came down to a choice of trying to fix it or resell it at a very significant loss. I did quite a lot of digging around on the internet to see if I could find any DIY posts regarding repairing the Akito and to my great chagrin the only information that I found was some posts explaining that Linn was on record as saying it is not possible to replace the bearings in a first generation Akito arm. Please note that this has not been verified with Linn. At this point I was starting to really worry. I had visions of an investment of several hundreds of dollars becoming a shelf ornament. I didn't give up and kept digging in the hopes that if I put together the right search wording something useful might pop up. It eventually did. In Bulgarian! I hit the Translate button on my web browser and there it was, a fairly complete explanation of how to rebuild a first-generation Linn Akito with many photos. The translation wasn't perfect but it was good enough to understand what the guy (or gal) did and enough for me to conclude that I could probably do this.
Renewing a Linn Akito can be broken down into the following steps:
The first step in disassembly is to loosen the Allen socket screw, remove the phono cable socket from the bottom of the arm base and cut or pull apart the wires. It is not possible to reuse the existing internal wiring, simply because the wires are too short to be recovered during the disassembly process. The only explanation that I can imagine for making these wires so short is that Linn decided during the design process that this arm would not be repairable!
The next step is to separate the armwand from the yoke. A little gentle prying with an Exacto knife or something similar breaks the glue joint inside the plastic caps that cover the bearing screws. The glue was pretty strong but eventually broke loose without damaging the hard plastic caps. Under these caps are the brass bearing screws. They are painted black but they are soft brass and glued in. Trying to unscrew them will just ruin the head and then it would be impossible to get them out without destroying them. The project is then over as these bearing screws are not available for purchase anywhere. The only options left would be to buy another tonearm or pay a machine shop a very large amount of money to make new bearing screws. Either way, your budget just doubled! Using a small propane torch to heat the head of the screw gently for about 8 or 10 seconds melts the glue and allows the screw to turn. Too much heat will of course burn the black finish away and leave some difficult repair work. Special care must be taken to use a flat head screw driver that matches the groove in the bearing screw as perfectly as possible as the soft metal can be very easily damaged. Once the bearing screws are removed the armwand can be lifted away from the yoke. Immediately taping the old wires to the armwand so they don't accidentally slide out will avoid a lot of work later when it comes time to thread the new wires through the tonearm. The old wires can also be used as a pull wire.
Removing the vertical bearings simply requires gently tapping them out with a small hammer and screw driver. Being careful not to scratch the bearing housing of course. Using something non-metal would be even better for tapping out the bearings. Removing the horizontal bearings is the same process however first requiring the removal of the nut that holds the assembly together from the bottom and pulling out (by hand) the yoke assembly. The bearing housings and the yoke shaft were then cleaned and set aside for re-installation. I did gently pass a 400-grit sand paper on the yoke shaft to make sure there was nothing stuck on it that would interfere with the new bearing fit.
Photos: Phono cable socket removed, vertical bearing socket after bearing removal. Note: there is no photo of the vertical bearing screw before removal due to a camera file mishap!
The unit uses 4 identical bearing that are quite common and a local bearing store had the required bearings in stock. (I just asked for 6 x 13 x 5 mm flanged bearings) However there is a bit of preparation required before installing them. The original bearings are unshielded, there are no covers to keep lubrication in and dirt out. This, of course, is one of the reasons why they are so susceptible to failure over time. The horizontal bearings especially, as dust can easily get in from both the top and the bottom. Most bearing shops only stock shielded bearings and this is a better option anyway. My Bulgarian teacher explains that he removed the shield from the inboard side of all 4 bearings, then cleaned out all of the grease with some solvent and then added dry lubricant. The outboard shield was not removed as it serves to keeps dirt out. Removing the grease is necessary to reduce bearing friction to the minimum possible. The dry lube of course makes the bearing slipperier. The very helpful man at the counter in the bearing store recommended Teflon dry lube. This is what I in fact ended up using however I did not buy his $55 can and got the same thing at Canadian tire for $10 (also his suggestion!).
He also explained to me how to remove the bearing shield from one side. The bearings I purchased had permanent shields, which means that you have to destroy the shield to remove it. All it takes is an Exacto knife to pierce the shield and lift up the edge enough to get a tiny screwdriver in and pry the shield off. (see photos) The 4 bearings cost me about $60. tax included. It is possible to order the exact same bearing in ceramic. Most bearing shops don't stock this item for the simple reason that they cost 4 to 6 times more than the steel version. The advantage is that they have lower friction compared to the steel bearing - Teflon lube scenario. Steel was good enough for Linn and it was going to be good enough for me too as I wasn't keen on adding another $200 to $300 to my project cost! With the inner shields removed and the grease cleaned out with grease remover, the bearings were set aside to dry for a few minutes and then the inside was sprayed with Teflon lube. It just takes a few minutes for the liquid propellant to evaporate and the bearings are ready to install.
Installing the new bearings is pretty simple. The housings were, of course, cleaned first as there was some deposits on the surfaces. All it took was a cotton-tipped cleaning stick. (Q-Tips) All four bearings slipped in with just a light pressure. Before mounting the tonearm yoke, the cueing/anti-skating platform must be reinstalled. The second photo below shows two bearing shields after removal.
I decided to purchase a new metal platform from Audio Origami in Scotland. I believe that Audio Origami is the only source for this part. Surprisingly, the arm arrived in only a week! A-O sells this part to DIYers for 100 pounds and that included shipping to Canada! They also offer supply and install service for 120 pounds. The A-O platform is excellent, it is virtually identical in shape and size to the original and the anti-skating parts fit into it perfectly. A-O claims that it provides a very significant upgrade in the sound of the Akito, well, it certainly can't hurt! Johnnie at Audio Origami was quite helpful during this project as he has a vast experience with Akito arms. He didn't miss an opportunity to offer his parts and services along the way which is fine too, however I wanted this to be a DIY project as much as possible. A-O can do all of the work that I did on this rebuild for those who don't feel that they have sufficient DIY skills.
Installing the new tonearm wires requires threading them through the base and the armwand prior to installing the armwand back on to the yoke. If the old wires are still inside the arm, the threading process is relatively simple. If not, then it's not! In my case the old wires accidentally got pulled out so I had no choice but to figure out how to thread the new wires. I had a leftover section of "1877" tonearm Litz wire. An excellent product that I can certainly recommend. 1877phono is a brand name for some of the products manufactured by Zavfino, a Canadian company with distributors in North America, Europe and Asia, that produces a wide variety of cables and components including turntables and tonearms. Back to my story; what I discovered, the hard way, is that there is a significant restriction in the diameter of the inside of the arm tube just ahead of the point where the wires come out through the bottom of the tube and enter the base assembly. It took about a half an hour of work but I finally succeeded in getting the wires past the restriction in the tube. I had previously removed the connector at the headshell end of the arm. This required a few seconds of heating with the propane torch in order to soften the glue. After that it pulled out easily with small pliers. Once the new wires were threaded, they were secured at both ends with some masking tape before proceeding with the next steps.
The tonearm yoke slipped into the horizontal bearings with just a slight hand force and it is held in place by a brass nut with very fine threads. This nut must be very carefully screwed in with a nut driver as cross threading it would be disastrous. The fine threads allow for a precise adjustment of the tightness of the bearings. Too tight will restrict the rotation of the yoke whereas too loose may give vibrations a place to live. Not having Johnnie's experience, I decided that the best way to set the tightness would be to use the anti-skating spring as a reference. Without the armwand installed in the yoke, I set the anti-skating tension to 0.6, turned the yoke all the way clockwise and let it go. With loose bearings it snaps back to rest position quickly and smoothly. I simply tightened the bearing nut very gradually until the snap back started to slow down, then backed off just a touch.
Reinstalling the armwand bearing screws turned out to be quite an adventure. As mentioned earlier, these screws are soft brass and on top of that the threads are very tight. Screwing in the first one became harder and harder as it went further in. Finally, it just wouldn't go in any more, jammed! I ended up having to use pliers to get it out, which of course destroyed the first few threads. Slight panic at this point! After close examination I found a tiny black spot embedded in the bottom of the thread at about 3 threads in from the tip. This was enough to cause the screw to jam. After cleaning this spot away the screw went in easily and smoothly. However, the damage was done. The screw would not go in all the way due to the damaged threads. I took the screw to a local machine shop and 1 week later and $70. poorer the screw was ready. The machine shop did a very good job of removing the damaged threads and repairing the mangled screwdriver slot. The loss of the last 3 or 4 threads did not in any detectable way cause any looseness in the fit. The lesson to learn here is that the threads on these 2 screws are such a tight fit that even a speck of dust will cause problems in reassembly. Make sure they are perfectly clean before trying to put them back in their sockets. These screws are not replaceable, if you damage one or lose one, it would likely cost a couple of hundred dollars to get a new one made in a machine shop.
The stub shaft on the end of the vertical bearing screws slides into the bearing with light resistance. If the screw becomes hard to turn it means that the stub shaft is not going in straight. Back out and realign. Setting the bearing tightness was pretty simple. I just went tight enough to eliminate any side-to-side play and made sure that the vertical movement was in no way restricted. Normally these screws are glued in place. I have not done this yet as I have to find the right product. I presume some kind of Locktite will do the trick. I tried a drop of hot-melt glue but it does not stick to the metal. The plastic caps were reinstalled without any glue as they fit quite snugly with no risk of falling out. A bit of black felt pen touch ups to the scratches that I left while trying to get the screw out and it looks almost like new.
Soldering the internal wires is not easy work for an old guy with shaky hands, bifocals and very rusty soldering skills! The Akito socket that received the tonearm cable has very small pins to which one must solder very, very small wires. It took a lot of sweat and effort but I finally got it done. If you are shaky or inexperienced with this kind of soldering, you may find this step the hardest part of the project.
Photos below: vertical bearing screw with damaged threads, repaired bearing screw installed, partial assembly, finished arm in service.
The arm is now completely assembled, back in service and working beautifully. I am of course very pleased with the final outcome however it is important to note that in the end, this tonearm cost me about $300 more than my original purchase price and many stressful moments. I would have liked to provide a few more photos but sadly, many of the photos that I took during this project disappeared into the Ether, never to be found! Here is a link to the Bulgarian web page for more photos.
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© Copyright 2021 Roger McCuaig - firstname.lastname@example.org - www.tnt-audio.com
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