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 ...
A few weeks ago I spotted another turntable being auctioned locally on ebay. The price seemed very good and I bid for it and won. It was a JVC JL-A1 which I got for a very reasonable £20 and was able to collect. The unit had been in the family from new and was in very good condition. Just a few issues due to age , namely the hardening of both rubber and lubricants with age. I had read in the vinyl engine forum that it was similar to the PL-12 and I wanted to find out, plus I enjoy working on decks.
As you can see from the pictures it is very similar. Speed change on the left (buttons rather than levers) with cueing lever on the right. S-shaped arm with removable headshell and dial anti skate. The only significant functional difference is that the deck is an automatic, revealed by the Reject button at the bottom right. This feature means the platter only rotates when the arm is cued at the start of the record, and at the end of a side (or when you press the reject button) the arm lifts automatically and returns to its original resting position. Magic !
I removed the mat and platter, which was a good deal lighter than the pioneer. The belt hooks over the motor spindle as per the pioneer , and can be attached via two cut-outs in the platter. The only difference you see are the white nylon cogs which form part of the automatic arm return mechanism. The top plate of the deck is supported by 4 springs to isolate it from the plinth which is chipboard with a veneer to make it look like real wood. The plinth is a little less substantial than the pioneer one, shallower and with a hardboard panel on the lower side.
As with the Pioneer I removed the 3 rubber bushes and along with the belt and rubber mat they had the same process. Clean in warm soapy water, dry and treat with Platanclene roller restorer in a plastic bag for an hour.
The main bearing was very stiff. The whole bearing assembly can easily be removed, its held in place by 3 screws through the top plate. Once removed I could see it uses the same side screw to hold the spindle in place. I removed the screw and carefully extracted the spindle. A few taps elicited the ball bearing that sat at the bottom of the bearing well. All were sticky with old hardened grease so I washed all parts in warm soapy water , dried and further cleaned with Servisol 10 contact cleaner. The JVC bearing well is not brass but some alloy, with what looks like different material for the base possibly Delrin. Once I had cleaned the well with cotton buds and the spindle and bearing, I reassembled adding a blob of Moly grease to the spindle. Now spins smoothly and effortlessly.
As you can see from the picture of the motor , the springs didn't have foam cores to act as shock absorbers. . However around the top edge of the wooden plinth were blocks of foam rubber which I presume served the same purpose, and as with the PL12 were perished. The top plate is held in place by 3 catches which you disengage from the top via 3 screws, similar again to the PL12. You can lift the top plate as before but there is not much slack from the white mains cable which passes out of the plinth through a metal plate with a compression collar. Removing this was the hardest part of the whole process, but it enabled me to gain full access to the deck.
I found some foam rubber and added some cores to the springs a la PL12. I replaced the grounding wire as the original had been cut and re-joined from some older wire. I fitted a length of wire and used a couple of soldered eyelets at each end.
Reassembling the deck was easy. I applied power and the motor was absolutely silent in operation. Checking the speed with a strobe disk indicated no problems, it kept good pitch at 33 and 45 and the speed selector worked well. The JVC mounts the selector arm in a nylon sleeve which is a nice refinement as the PL12 arm is inclined to rattle.
I tested the return mechnism and while it did return the arm to its holder, there was a clicking sound at the end. The gears on the top were not quite disengaging from each other . I lubricated all of the pivot poitns in the cogs aboe and , underneath again I applied small drops of oil to the pivots for the various arms. The black plastic sliding rod you can see in the lower right of the picture has a captive rolling ball bearing between it and the white nylon housing it extends into . This was a bit sticky and I applied a drop of oil here and worked the bearing in and out till it seemed effortless.
Reassembly and the whole automatic mechanism worked fine, no clicking this time.
I finally tried playing a record. The deck had come with its original headshell fitted with an Ortofon FF15 cartridge. I've another deck with one of these and it's an excellent model. I always fit a new stylus, so ordered a replacement from William Thakker in Germany, who are very good. I choose one of their OEM stylus for around €27. In the meantime I tried the Pioneer headshell with the Shure M75, and it sounded quite good. It was a little noisier, some background hum, but not too bad.
The stylus came and I decided to use a different headshell initially, as , while the JVC original looked good, it was quite flimsy and had some hardened damping material stuck inside. Interestingly using a generic and very good headshell (£6 from ebay) I got no music from the left channel. After a bit of experimenting, it appeared to be a poor connection inside the headshell collar, and removing the rubber washer from the plug half of the headshell sorted the connection. The deck was also noticeably quieter, my hum had gone. With the generic headshell and the FF15 with OEM , it does sound very good indeed. is it better than the PL12 ? hard to say, It has many of the same qualities and perhaps the motor is a little better. I think the pitch on the PL12 is not as good as the JVC, but that could be the motor is more worn. certainly the JVC Motor is more modern looking. The JVC has a tiny amount of in/out play in horizontal arm bearing, but the various arms and levers inside the deck for the auto mechanism mean that the two locking nuts are inaccessible. I think I may live with that.
Comments
I have the same turntable but I have few problems and I thought maybe you could help.
Mine is also automatic but the problem is that always when the lp ends the arm goes back but it won't stay there, only a moment and then it goes back and lands on the middle of the lp with bad noise. Why is it doing so? Is it possible to make it stop doing it?
Sometimes the arm decides to do the same thing not when the lp ends but when it is in the middle. But if I understood right the last thing may be because of the wrong anti skating and the weight? What anti skating and weight did you put on your turntable?
Really hope you could help me.
Best Wishes,
Merilyn
I would suspect that the grease in the automatic mechanism has become sticky with age and the system of gears and rodes which take the arm back at the end of the side (or by pressing the reset button) is not working as it should.
One of my pictures shows the deck from above with the platter removed. This shows the central spindle which has a geared collar. The spindle can turn freely becuase the larger gear to one side has a notch of missing teeth. I believe that this is not working quite right. The lubrication on that larger wheel is probably preventing it from presenting the missing section to the smaller gear, which should be its default state. You can sort of simulate the whole provess by manually moving the arm across and watching how the bigger wheel finally gets moved into engagement with the smaller gear. Its easy to understand when watching but harder to explain.
I think you probably need to lubricate the central axle of the large wheel with a few drops of oil, best is sewing machine oil which is thin. Then work the mechanism to get the oil into the coupling. This might be enough. However there are a few rods and wheels inside which can only be accessed from beneath. Only try this with the power unplugged at the mains BTW.
Basically a few drops of oil in a relatively few places should sort this out.
the other approach is to remove the whole auto mechanism and turn the deck into a manual. This is poossible but quite fiddly and you will have the issue how to turn the deck on and off, which currently a rod beneath does when the arm moves across.
I think a bit of oil and TLC on a deck , which, after all is best part of 35 years old, should get you working again
I dont think your problem is connected with anti skate or the balance weight. On mine these are both set to 1.5grams which is correct for the Shure M75 cartridge I use. be aware that the balance weight i.e the larger weight has to be balanced and then set the smaller black ring to zero, then rotate both till you get the right weight.
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 ?
Have a looke here http://4.bp.blogspot.com/-dJ3CmjgV45k/UuTdY_2KnmI/AAAAAAAACIo/ZoTLbobX49U/s1600/IMG_1036.JPG
You can just see the silver bearing inside the white box shaped holder that has the black rod running through it
I gave the JVC to a good friend as a special 50th birthday present , so i cant tale a look at mine.
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
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 beneath
Sorry I can't tell you exactly as I gave the deck to a good friend as a 50th birthday present.
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.
Accidentally I lost the ball bearing while cleaning it and I would like to buy a new one, can you tell me diameter please?
Thank you very much!
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 enough
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.
As you say a 1/8" (3.175 mm) diameter ball bearing should be ok, I will buy this diameter.
For who asked about the weight, if still usefull:
https://ibb.co/n2HzDH
https://ibb.co/izJH0x
https://ibb.co/mPxS0x
https://ibb.co/nzS5nc
https://ibb.co/f9vfLx
https://ibb.co/ju8Zfx
https://ibb.co/jkND7c
https://ibb.co/fB1ZDH
(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)
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.
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.
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.
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.
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.
A little bit of "Sellys plastic glue" and a cable tie, and I'm back in business!
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.
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!
Now I'm wondering why the platter keeps revolving on mine when the arm returns as you suggest it should stop... Any idea?
Len
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.
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 too
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.
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.
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.
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?
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?
Regards,
Stuart Longland
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.
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.
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
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.
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.
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).
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 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.)
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.
Many thanks for the advice.
Regards,
Stuart Longland
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.
I trust William Thakker in Germany to supply correctly specified belts .
Good luck, and keep us posted
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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?
https://www.bunnings.com.au/kincrome-450g-moly-high-performance-grease_p0028282
Regards,
Stuart Longland
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.
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 up
Removing the platter: 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.
In the end, I just had to be a bit more firm with it and eventually the press-fit platter popped off.
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.
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.
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.
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.
Comparing against a CD (1967-1970) it doesn't line up perfectly, but it's also possible they're two different recordings. The pitch matched though, and that I thought was the important bit.
Some asked about the size of bearing: 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.
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.
Regards,
Stuart Longland
However the wiring is very simple , especially on the signal side. The 4 pins on the cartride correspond to the 4 wires that pass through the arm. These are soldered to a junction board clse to the base of the arm (see internal photors, which joins them in pairs to the two shieled signal wires which exist the table. The Left and Right signal wires from the cartridge (white and red normally) should trace through each to one of the two RCA plug centre pins (left and right), while the Left Ground and Right ground (Blue and Green) should trace through to the two RCA outer barrel of the connector.
Sometimes a dead channel is caused because the headshell socket is not functioning correctly. If you remove the headshell, inside the socket in the arm are 4 brass pads which are spring loaded to contact the set of 4 brass contacts on the headshell side. The pads inside sometimes stick in. a squirt of contact cleaner in the socket end of the arm and exercise each pad a dozen times with a wooden cocktail stick or the wooden end of a match. You might find that removing the rubber washer from the headshell side also helps.
Cartridges sometimes fail on one channel and swapping the wires in the headshell will help diagnose if the faul remains on one side moves to the other channel