tag:blogger.com,1999:blog-8000191682087974772.post534694948069471921..comments2024-03-21T08:21:38.675+00:00Comments on mending things: Restoring a JVC JL-A1 TurntableMr Iveshttp://www.blogger.com/profile/14965084993191032538noreply@blogger.comBlogger28125tag:blogger.com,1999:blog-8000191682087974772.post-79532047370147106942021-04-18T02:18:34.829+01:002021-04-18T02:18:34.829+01:00Hi, finally attacked the turntable this morning.
...Hi, finally attacked the turntable this morning.<br /><br /><b>Removing the platter</b>: that was the first problem I encountered, as this had been done maybe once in the turntable's lifetime (apparently the belt has been replaced once before). I undid the screws on the bottom looking for clues (it was on stiff enough that it stayed put with the assembly up-side-down), spotted the 3 screws that held the bearing in place, but no obvious clues.<br /><br />In the end, I just had to be a bit more firm with it and eventually the press-fit platter popped off.<br /><br />I cleaned out the old lubricant which had become slightly stick (with sink plugged so that little ball bearing didn't go running off!), gave the chamber a good wipe out with a cotton bud and flushed it all out before wiping down the shaft and bearing with paper towels. Then, packed it with the moly grease I linked to above.<br /><br />Maybe I used too much, but the playback speed was still slow after re-packing and putting it all back together. The platter spun, but would soon come to a stop maybe 30 seconds later. Tried the "test" I did before (The Beatles - Abbey Road) and again, it sounded slow. So, plug went back in the sink, the platter came off (much easier this time), and out came the bearing for round two.<br /><br />When I was in Bunnings yesterday buying the grease, I also saw this lubricant which I thought might work for the motor: https://www.bunnings.com.au/100ml-household-oil-lubricant_p5810258 Since the Moly Grease I bought was clearly too heavy (or maybe I used too much?) I figured I'd try this out. So another thorough cleaning out, drying out, a few drops of this alternate oil in, and put it together.<br /><br />Spinning the bearing in my fingers, there was a lot less resistance now, and putting the platter back on, it was spinning for much longer. Hooked the belt up, plugged the turntable back in and gave Lennon's masterpiece another spin.<br /><br />Comparing against a CD (1967-1970) it doesn't line up perfectly, but it's also possible they're two different recordings. The <b>pitch</b> matched though, and <i>that</i> I thought was the important bit.<br /><br /><b>Some asked about the size of bearing:</b> The one I have is about 4mm in diameter. I didn't measure it exactly (I guess I can pull it out and get the vernier calipers onto it if needed) but that measurement might be a rough starting point.<br /><br />Many thanks for this post and the advice though, this page is a great guide for fixing these turntables, and it'll be good to re-sample some of my records on this unit as frankly, the Kenwood P-110 I used prior is a toy compared to the JVC.<br /><br />Regards,<br />Stuart LonglandAnonymoushttps://www.blogger.com/profile/17063792986179546074noreply@blogger.comtag:blogger.com,1999:blog-8000191682087974772.post-79329898333659534682021-04-10T10:52:12.609+01:002021-04-10T10:52:12.609+01:00Hi Stuart,
You can use a wide range of lubricants...Hi Stuart,<br /><br />You can use a wide range of lubricants on turntable main bearings , as long as they are just oil or grease. So penetrating oil or engine oil which contain detergents are not a good idea. A lot use gearbox oil, or sewing machine or clipper oil.<br /><br />on the JVC you may find the auto return gears need a clean and relube, again, simple oil can oil is often fine, if the old grease has gummed upMr Iveshttps://www.blogger.com/profile/14965084993191032538noreply@blogger.comtag:blogger.com,1999:blog-8000191682087974772.post-55673352753144278122021-04-10T10:12:53.485+01:002021-04-10T10:12:53.485+01:00Okay, so haven't tried taking apart the turnta...Okay, so haven't tried taking apart the turntable, but figured I'd stock up on the materials first. Looks like Thakker aren't shipping outside of the EU (a bummer, but yeah, China's little gift has thrown a spanner in the works):<br /><br />https://cdn03.plentymarkets.com/x8owdo162lc9/frontend/home_slider/COVID_info_slider_en_01.svg<br /><br />I was looking to get the bearing lubricant that they sell since it's clearly intended for this task. I did look around for Moly grease… should I be looking for something specific or should something like this do?<br /><br />https://www.bunnings.com.au/kincrome-450g-moly-high-performance-grease_p0028282<br /><br />Regards,<br />Stuart LonglandAnonymoushttps://www.blogger.com/profile/17063792986179546074noreply@blogger.comtag:blogger.com,1999:blog-8000191682087974772.post-86692181024067919332021-03-14T08:30:27.294+00:002021-03-14T08:30:27.294+00:00Thanks Stuart for the confirmation about the mains...Thanks Stuart for the confirmation about the mains frequency. It's important to thoroughly clean out the main bearing assembly. the one I had was very stiff, and I suspect the original oil or grease had started to become gummy, which creates a breaking effect.<br /><br />With these fixed speed motors, and well lubricated bearings, speed is entirely an issue of geometry and ratios. However an equilibrium needs to be achieved as the top plate is decoupled by springs, and the belt is attached to the motor, decoupled from the top plate by flexible rubber mounts. Things can move a bit, and a belt that is too tight will tip the motor in slightly. Rubber , like oil, seems to change with age and climate, and I'd also suggest doing some restoration on the 3 motor mounts, os mechanical noise from the motor can get into the replay system, be picked up by the stylus and appear as some background hum only when a record is playing.<br />I trust William Thakker in Germany to supply correctly specified belts .<br /><br />Good luck, and keep us postedMr Iveshttps://www.blogger.com/profile/14965084993191032538noreply@blogger.comtag:blogger.com,1999:blog-8000191682087974772.post-810618906968790582021-03-14T07:55:11.207+00:002021-03-14T07:55:11.207+00:00Hi, Replying inline.
My initial reaction is that ...Hi, Replying inline.<br /><br /><i>My initial reaction is that the main bearing is the more likely culprit. It probably needs a good clean, relube and possibly the ball bearing replacing. As others have indicated, the original *may* be a 1/8" but we don't have a definite size match. With the belt unhooked from the motor, you should be able to free spin the platter by hand and it should run for several minutes. If it doesn't it's certainly that the main bearing is gummed or dry.<br /><br />it could be the motor, and it's worth putting a few drops of sewing machine oil in the top oil point, but I think the motor is less likely.<br /></i><br /><br />Ahh so that'd be the bearing that allows the platter itself to spin. That sounds like an easy test. I'll see if I can procure some suitable lubricant and see how it goes. Sounds like a better plan than trying to replace the motor… especially as messing with mains power stuff is a hassle with electrical laws in this country (Australia).<br /><br /><i>I assume your friend had it running at the correct speed at some point ? AC synchronous decks use a motor where the speed is locked to the mains frequency, and not a function of voltage. While many have voltage selector switches, they also shipped with two sizes of motor pulley to accomodate 50Hz and 60Hz regions. a Deck fitted with a 60Hz pulley will be slow in a 50Hz country, and a 50Hz pulley will be fast in a 60Hz country. Do you believe the deck has travelled ? That all said, it sounds like the percentage is too small for this explanation</i><br /><br />I believe so, the back of the unit has factory-applied stickers that state it's a 220-240V 50Hz unit, so it should have the correct pulleys and belt for a 50Hz mains system. I realise it won't be all that sensitive to voltage fluctuations (mind you, the motor likely won't thank me if I give it 110V 50Hz), mains frequency is the key metric here, hence I checked it. (As a day job, I write software that polls electricity meters for things like line frequency and energy used, so had a number of meters on hand I could check.)<br /><br />I think the speed is close enough that it's likely a friction issue that you've alluded to… I'd imagine if it was a 60Hz pulley it'd be wildly off (in the order of 17% not the ~5% observed). Other outlier possibility I guess is the possibility the belt is stretched and not providing correct tension, but the lubricant and bearings look like a good first step to check.<br /><br />Many thanks for the advice.<br />Regards,<br />Stuart LonglandAnonymoushttps://www.blogger.com/profile/17063792986179546074noreply@blogger.comtag:blogger.com,1999:blog-8000191682087974772.post-16943259112500871382021-03-14T07:34:28.885+00:002021-03-14T07:34:28.885+00:00Hi Stuart,
My initial reaction is that the main b...Hi Stuart,<br /><br />My initial reaction is that the main bearing is the more likely culprit. It probably needs a good clean, relube and possibly the ball bearing replacing. As others have indicated, the original *may* be a 1/8" but we don't have a definite size match. With the belt unhooked from the motor, you should be able to free spin the platter by hand and it should run for several minutes. If it doesn't it's certainly that the main bearing is gummed or dry.<br /><br />it could be the motor, and it's worth putting a few drops of sewing machine oil in the top oil point, but I think the motor is less likely.<br /><br />I assume your friend had it running at the correct speed at some point ? AC synchronous decks use a motor where the speed is locked to the mains frequency, and not a function of voltage. While many have voltage selector switches, they also shipped with two sizes of motor pulley to accomodate 50Hz and 60Hz regions. a Deck fitted with a 60Hz pulley will be slow in a 50Hz country, and a 50Hz pulley will be fast in a 60Hz country. Do you believe the deck has travelled ? That all said, it sounds like the percentage is too small for this explanationMr Iveshttps://www.blogger.com/profile/14965084993191032538noreply@blogger.comtag:blogger.com,1999:blog-8000191682087974772.post-67152486149251688662021-03-14T02:10:53.157+00:002021-03-14T02:10:53.157+00:00Hi,
Just stumbled on this blog, recently I acquir...Hi,<br /><br />Just stumbled on this blog, recently I acquired a JVC JL-A1 in mostly working order from a friend who was downsizing house and had gotten rid of all his records. After digging out my preamp to interface it to the line-level input on my computer sound interface, I pulled out a record (The Beatles - Abbey Road) and tried it out.<br /><br />It played fine, audio sounded good, but it sounded slow… so I got Audacity to capture the first track ("Come Together"), and compared that to a recording of the same song that I had on a CD (from the "1967-1970" album). Synchronising the start of both tracks, I observed the playback from the turntable was slow. I had sampled at 48kHz; when I changed the sample rate to 50.185kHz -- the recording played correctly.<br /><br />Now, this works for digitising, if slightly annoying. It'd be nice to correct the speed of the motor. Since this is a synchronous motor, it's deriving its speed from the mains line frequency, which according to some electrical meter I have on hand (CET PMC-220), is sitting around 49.97Hz … not off frequency far enough to account for the nearly 5% error I'd have thought.<br /><br />In the blog article, I see mention of lubricating bearings in and around the motor. Could that be sufficient to get the motor turning at the correct speed, or should I be looking elsewhere?<br /><br />The other thought is that if the motor is the problem, maybe I replace it with a extra-low-voltage (≤24V) DC motor, perhaps a small BLDC motor with integrated hall sensors that I can whip up a small motor controller for. Problem there is what should I look for in terms of specifications? What motor shaft size, rotation speed and physical dimensions are appropriate for this turntable?<br /><br />Regards,<br />Stuart LonglandAnonymoushttps://www.blogger.com/profile/17063792986179546074noreply@blogger.comtag:blogger.com,1999:blog-8000191682087974772.post-21949783943006097702019-11-01T09:39:43.255+00:002019-11-01T09:39:43.255+00:00Hi,
I think the cog which sits around the spindle...Hi,<br /><br />I think the cog which sits around the spindle is a compression joint and should pull off. The big cog is held in place by a circlip which you should be able to remove from the top with a small screw driver. be careful it doesn't fly off . The spindle housing is held in place with 3 screws on the top and with the cogs clear you should be able to remove the whole thing and immerse it in some warm soapy water. I'm sure that the original grease has turned hard and thats why its not turning. Eventually that should loosen it up and lubricate and reassemble. There is a small ball bearing at the bottom of the spindle housing , and that needs t be cleaned or replaced tooMr Iveshttps://www.blogger.com/profile/14965084993191032538noreply@blogger.comtag:blogger.com,1999:blog-8000191682087974772.post-48073759382302405562019-11-01T04:15:17.726+00:002019-11-01T04:15:17.726+00:00Hi, I know this is an old post, but I'm having...Hi, I know this is an old post, but I'm having some problems with a Linear Design LD-500, which is a rebadge of this turntable. My spindle doesn't spin at all. I can't get the spindle with its housing out of the top plate without removing the auto-return gears, which I can't figure out how to do. I've also been unable to remove the spindle from the housing, even with the screw that holds it in place removed. Do you know how I can get the spindle out and moving again?Anonymoushttps://www.blogger.com/profile/15076212259528373852noreply@blogger.comtag:blogger.com,1999:blog-8000191682087974772.post-50961103643345967762019-11-01T04:13:46.723+00:002019-11-01T04:13:46.723+00:00Hi, I know this is an old post, but I'm having...Hi, I know this is an old post, but I'm having some problems with a Linear Design LD-500, which is a rebadge of this turntable. My spindle doesn't spin at all. I can't get the spindle with its housing out of the top plate without removing the auto-return gears, which I can't figure out how to do. I've also been unable to remove the spindle from the housing, even with the screw that holds it in place removed. Do you know how I can get the spindle out and moving again?Anonymoushttps://www.blogger.com/profile/15076212259528373852noreply@blogger.comtag:blogger.com,1999:blog-8000191682087974772.post-74044360947857105502019-09-29T08:45:53.164+01:002019-09-29T08:45:53.164+01:00Hi Len, if the auto-return works but doesn't s...Hi Len, if the auto-return works but doesn't switch off the deck id suspect the micro switch is sticky.<br /><br />If you disconnect the deck from the mains and lock the arm in place and remove the platter you can flip it over and remove the baseboard. If you then flip the deck so its restong on the rear of the deck on a soft towel, you can simulate a record play and rotate the spindle, which should show how the cogs and levers engage . The micro switch is visible in my underside picture. Its about 10mm x 20mm and has a metal lever along the top. The arm progress rod nudges this shut when a side completes. First thing is to spray contact cleaner inside the microswitch, using the fine tube which comes with servisol or deoxit brands. Important to get the tube in a recess in the switch. After application exercise the switch by depressing the top lever 100 times, then repeat spray and exercise. Mr Iveshttps://www.blogger.com/profile/14965084993191032538noreply@blogger.comtag:blogger.com,1999:blog-8000191682087974772.post-78067709504678899502019-09-28T21:06:49.131+01:002019-09-28T21:06:49.131+01:00Nice article, thanks for the detail you go to here...Nice article, thanks for the detail you go to here.<br />Reading as I was troubleshooting a problem with getting no sound from the left side. Was the same issue with an after-market casing and sorted by removing the rubber washer!<br />Now I'm wondering why the platter keeps revolving on mine when the arm returns as you suggest it should stop... Any idea?<br />Len<br />Lennoreply@blogger.comtag:blogger.com,1999:blog-8000191682087974772.post-31475411361312170892019-07-28T08:30:29.124+01:002019-07-28T08:30:29.124+01:00Thanks Drift for your message, glad your deck is r...Thanks Drift for your message, glad your deck is running againMr Iveshttps://www.blogger.com/profile/14965084993191032538noreply@blogger.comtag:blogger.com,1999:blog-8000191682087974772.post-48856782574240150142019-07-28T02:08:01.765+01:002019-07-28T02:08:01.765+01:00Thankyou for your post!
My A1 recently stopped wor...Thankyou for your post!<br />My A1 recently stopped working, it initially was very slow to spin up to speed & could only be started at 45rpm. The next time I used it, it wouldn't start at all.<br /><br />After finding your post and downloading the owners manual, I pulled the platter & back off, cleaned a few components, added a drop or two of sewing machine oil. <br /><br />Eventually I managed to get it turning but something still wasn't quite right. I had a leftover ball-bearing on the bench with no idea where it belonged. Thanks to your post, I managed to find its home! I spent another couple of hours turning everything by hand until I understood how it all worked.<br /><br />By this point I'd discovered the arm wouldn't auto return to the holder. It'd lift up at the end of a record & put itself straight back down.<br />It turned out to be a crack in the plastic which coupled to the shaft of the tone arm. This crack meant the grub screw was no longer gripping the shaft & thus wouldn't rotate the arm.<br />A little bit of "Sellys plastic glue" and a cable tie, and I'm back in business!<br />I also replaced a bit of foam on the end of the large metal arm/lever, so that it did not push the plastic rotators an extra 2-3mm, causing the tone arm to bounce off the stop when it returned home.Drifthttps://www.blogger.com/profile/03583510304022663611noreply@blogger.comtag:blogger.com,1999:blog-8000191682087974772.post-57051018669450043412018-02-27T13:54:01.055+00:002018-02-27T13:54:01.055+00:00Thanks for the update and the links to the dimensi...Thanks for the update and the links to the dimensions of the counterweigh, and good luck with the bearing.Mr Iveshttps://www.blogger.com/profile/14965084993191032538noreply@blogger.comtag:blogger.com,1999:blog-8000191682087974772.post-2809208347241565852018-02-27T12:56:01.403+00:002018-02-27T12:56:01.403+00:00Thank you, I've tried with a 4.7 mm ball and i...Thank you, I've tried with a 4.7 mm ball and it fits, but the spindle seems to be a little too high because the locking screw is near to touch the lower side of the spindle groove. <br />Without the ball bearing, the spindle go down about 2.5 mm, so I think it needs a ball bearing between 2.2 and 4.7 mm. <br />As you say a 1/8" (3.175 mm) diameter ball bearing should be ok, I will buy this diameter.<br /><br /><br />For who asked about the weight, if still usefull: <br />https://ibb.co/n2HzDH<br />https://ibb.co/izJH0x<br />https://ibb.co/mPxS0x<br />https://ibb.co/nzS5nc<br />https://ibb.co/f9vfLx<br />https://ibb.co/ju8Zfx<br />https://ibb.co/jkND7c<br />https://ibb.co/fB1ZDH<br />(97.57 g / 3.441 oz weight, 30.26mm outer diameter, 12.07mm inner diameter, 31.93 mm lenght without the plastic ring, 36.71mm total lenght with the plastic ring)Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-8000191682087974772.post-25659767272276144432018-02-26T15:27:46.811+00:002018-02-26T15:27:46.811+00:00Hi, well worth restoring. I cannot tell you exactl...Hi, well worth restoring. I cannot tell you exactly the size as I gave the deck to a friend, and I dont have a service guide. The user guide is downloadable from Vinyl Engine but it doesn't describe the bearing.<br /><br />The deck is quite similar to the Pioneer PL12D and that uses a 1/8" diameter ball bearing, , and I'd suggest trying that, I dont think it would do any harm, and is likely correct of close enoughMr Iveshttps://www.blogger.com/profile/14965084993191032538noreply@blogger.comtag:blogger.com,1999:blog-8000191682087974772.post-51909085438092795362018-02-26T14:57:34.906+00:002018-02-26T14:57:34.906+00:00Hi, I have the same turntable and I would like to ...Hi, I have the same turntable and I would like to restore it.<br />Accidentally I lost the ball bearing while cleaning it and I would like to buy a new one, can you tell me diameter please? <br /><br />Thank you very much!Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-8000191682087974772.post-65018837558825850502016-10-11T08:01:33.542+01:002016-10-11T08:01:33.542+01:00Hi Mr Ives - hope you read this given its an old t...Hi Mr Ives - hope you read this given its an old thread. I've been reading this blog with much interest as I got one of these today. Unfortunately the veneer on the left front corner was damaged in transit - any recommendations on how to go about fixing this/is it worth taking the deck off the plinth and redoing the veneer on the top only or getting a new plinth ?Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-8000191682087974772.post-33032974924100058002015-11-10T13:06:03.765+00:002015-11-10T13:06:03.765+00:00thx a whole lot for the quick reply and the whole ...thx a whole lot for the quick reply and the whole article, which is extremely helpful.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-8000191682087974772.post-24795949526978803562015-11-10T12:56:08.718+00:002015-11-10T12:56:08.718+00:00Hi Anonymous
Sorry I can't tell you exactly a...Hi Anonymous<br /><br />Sorry I can't tell you exactly as I gave the deck to a good friend as a 50th birthday present.<br /><br />Many Japanese decks share similar components and you may find the balance weight from a similar vintage deck from other brands fits on to your decks arm stub. They screw on using a gentle internal spiral with a ball race. The weight needs to be able to balance whatever cartridge you choose , then allow movement to apply the tracking force. While there is a calibrated ring on the front, they are only needed if you don’t have cartridge scales. <br /><br />Mr Iveshttps://www.blogger.com/profile/14965084993191032538noreply@blogger.comtag:blogger.com,1999:blog-8000191682087974772.post-37069277507921244472015-11-10T12:33:19.409+00:002015-11-10T12:33:19.409+00:00hi, i just purchased an used jvc jl a1, but the we...hi, i just purchased an used jvc jl a1, but the weight at the end of the arm is missing. is there any chance you can tell me the weight of this piece, so i could get someone to make one for me? thanks in advance!Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-8000191682087974772.post-68314302496678826472014-04-18T22:23:29.167+01:002014-04-18T22:23:29.167+01:00Hi Max , just got home and also saw what i think w...Hi Max , just got home and also saw what i think was your post on vinyl engine. I think you just need a belt which has to hoop around the underside ring of the platter and around the brass spindle. If the previous owner said it worked id expect the old belt to be maybe around the platter or in the box ? No matter but when you find the belt, which is like a large. Dark grey rubber band, you just hoop it around the rim of the ring on the underside of the platter, then drop the platter back on, then via the two access holes in the platter, loop the belt over the motor spindleMr Iveshttps://www.blogger.com/profile/14965084993191032538noreply@blogger.comtag:blogger.com,1999:blog-8000191682087974772.post-68694349951947224412014-04-18T21:00:42.386+01:002014-04-18T21:00:42.386+01:00hi really hope you get this message ive jut bought...hi really hope you get this message ive jut bought one of these and cant seem to get the turntale moving the metal rod sticking through the top spins but when i replace the metal disc that the record sits on it doesnt spin and nothing touchesAnonymoushttps://www.blogger.com/profile/12924306687485653630noreply@blogger.comtag:blogger.com,1999:blog-8000191682087974772.post-9986244389180113342014-04-18T07:43:12.532+01:002014-04-18T07:43:12.532+01:00Hi, sorry for the delay, i seemed to have a few co...Hi, sorry for the delay, i seemed to have a few coments regarding the blog that i didnt notice the email notifications for.<br /><br />The black rod is held captive in the white nylon piece, but there is a ball bearing sandwiched between the two pieces that allows smooth running. Do you have this ?<br /><br />Have a looke here http://4.bp.blogspot.com/-dJ3CmjgV45k/UuTdY_2KnmI/AAAAAAAACIo/ZoTLbobX49U/s1600/IMG_1036.JPG<br /> <br />You can just see the silver bearing inside the white box shaped holder that has the black rod running through it<br /><br />I gave the JVC to a good friend as a special 50th birthday present , so i cant tale a look at mine. <br /><br />The other thing it could be is if you look at that picture you will see further toward the back of the deck is a metal piece, gold or brass in colour that is hooked , it pivots and carries a white nylon arm which touches the micro switch. If you look at the hooked end i.enthe end furthest from the micro switch, you will see there is a pad of rubber. This makes contact with the arm raise mechnaism. Sometimes the foam rubber pad perishes with age and needs to be replaced or the arm doesnt raise properly. Hope this helps , sorry for the slow reply<br /><br />Sometimes you just have to remove the platter,balance the deck on its back, remove the bottom, and simulate the movement of the arm while watching which mechanisms it engages with beneathMr Iveshttps://www.blogger.com/profile/14965084993191032538noreply@blogger.com