JVC-Q7 Resurrection
I told you all in my introductory post that I was about to attempt the resurrection of my JVC QL-7 turntable after it had been stored for 20 years. Well, the first strains of Beethoven’s 5th seemed to indicate that I had achieved some modicum of success. It has not been an easy exercise for me, as I no longer have easy access to all of the bits and bobs that keep appearing on my “need” list. Nevertheless, it has been fun and the journey to vinyl is not over yet!
The first thing I did was to disassemble the turntable feet. The rubber balloons surrounding the suspension coil springs had disintegrated. I removed all of the old rubber and used silicon sealer to hold the springs in position between the top convex metal cup, which is attached to the mounting bolt and the lower acoustic foot pad. There is some microphonic transmission from the cabinet that it stands on so I have a set of M6 threaded chrome plated spikes which I will install in place of the feet when time allows. I do fear that the threads in the turntable plinth are SAE and not metric, which may defeat this exercise.
I removed the turntable motor assembly from the plinth and opened up the shielding around the power supply and replaced the power cord by soldering a new cord onto the transformer connector board. Back in the plinth, the turntable motor achieved speed lock instantly and rotation was silent and without any hint of problems with the bearing. Likewise the tone-arm bearings were just fine as was the anti-skate mechanism. The only problem was the tone-arm lift device had lost it’s silicone oil, which I ordered on the evil bay. It came in a little 10ml syringe. Considering that the turntable had been dormant for 20 years, I was a very happy bunny.
The only pick-up cartridges that I had packed with the turntable were my “less expensive” ones - an Ortophon SL-15 elliptical MC in an Ortophon head-shell, a Pickering D-350 MM spherical in a SME head-shell and a JVC Z1 spherical MM in the original JVC head-shell. I also have a B&O SP 6 and a Pickering V15-AM1.
The Pickering D-350 has lost it’s stylus’ diamond tip. Just the very tip, the base is still there. I must assume that the adhesive used between the diamond tip and the base deteriorated over time. The JVC Z1 was wrapped in light foam during it’s long sleep and the stylus shaft must have been pushed very slightly to one side. The shaft has taken a set to the side (it’s definitely not bent) so that it is very slightly off-centre, but it still works fine and output is identical on both channels. The Ortophon SL-15, being MC, didn’t factor into my plans when I discovered that my NAD amp does not have a proper phono input. It has input sockets marked “Disc” and it has an input selector button on the front marked “Disc” but it turns out that this input is line level! Really! Would it have made the thing that much more expensive if the manufacturer had included a couple more components to give it a proper RIAA phono input stage? Maybe £3.00 which would translate as £15 on the RRP? How mean can you be? So, I had to find a phono pre-amp. Cheap but decent. I decided that I may as well find one that was switchable between MM and MC cartridges. I found a Pro-Ject Record Box-e which seemed to tick all the boxes, especially the one for small size as I have limited space. Because I didn’t seem to have a pickup cartridge that I could totally trust, I decided to order a Shure M97xE.
Then the question of mounting the cartridge arose. I ordered a head-shell from evil-bay for £8.95 that is a total disaster. It has been manufactured by taking a cast from a genuine head shell and making a mould, casting an aluminium copy and coating it with a thick, shiny powder coating that changed the dimensions and makes the screw-head slots in the top too narrow. I eventually went here:
Then I needed mounting bolts and nuts. £11.95 for a set? Really? I found these people on evil-bay: Beware, I ordered three different lengths of M2.5 machine screws and 50 nuts, but it took two weeks to finally receive the 6mm screws. Remember also that the ideal mounting nuts and screws should be made of aluminium. I also would not use these steel screws and nuts with a MC cartridge.
Finally, I had to disconnect and move the CD player out due to space limitations, and place the turntable in it’s space. Now I was ready to rock ’n roll!
My vinyl collection had been residing in my garage, which is not attached to the house and is very damp. The roof leaks. The records were packed tightly in cardboard boxes and the boxes were positioned such that some had the discs flat and others had the discs vertical. I expected total disaster - warping and mildew and polythelene leach from the inner sleeves. Amazingly, the discs were in perfect condition! A very few, from one box, had a slight mildew dusting which came off readily with a velvet brush damped in distilled water and a dash of vinegar. My record cleaning kit has disappeared so I am using one of those velvet brushes for taking lint off your coat and a soft micro-fibre cloth which is one of a pack of four different kinds from ASDA kitchen supplies. They work a treat once you get the hang of holding the disc and rotating it without getting finger prints on it.
After setting up the Shure cartridge correctly, I set the tracking at 1.75g (as specified for use with the brush down) and played track 1 side 1 of my proof pressing of MCA 1001, Neil Diamond’s Hot August Night. As I had overseen the mastering process of this release I know it intimately. At first the sound quality was very thin but after I had let the cartridge “bed in” a while (three days) I had the sound that I was expecting. Rich, warm, detailed with well controlled bass and silver highs. The high-level percussion mids were well controlled and the bass was not over-cooked.
Once I have replaced the turntable plinth feet with spikes, I will report back on the result. I have also been given a Cambridge Audio Azur 540R AV amp to try, but I doubt that I will hear any improvement over my NAD. I now have the task of sorting my vinyl discs and deciding what I want to keep and what I should relinquish. I don’t have space for them all.
Conclusion: I much prefer the sound of vinyl to that of digital CD. Can’t say exactly why, but it just seems more “listenable.”
Reply With Quote
Originally Posted by RobHolt
