blog describing the process I mentioned that I believed that much of the content would be suitable for a wide range of 1970's Japanese belt drive turntables from the likes of Pioneer, Sony, Sansui , Kenwood/Trio etc.
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.