My aim here is to provide some basic guidance for anyone considering the purchase of a JBE turntable. My thanks to all those who have helped with advice relevant to this section.
The easiest way to identify an approximate age on your deck is to look at the motor casing on the underside of the plinth. There may be two stickers. The first is the Matsishita motor sticker which usually has a manufacturing date on it. The second is a JBE sticker giving the serial number. I do not yet have any understanding of how serial numbers may relate to the actual number of turntables produced. The Matsushita sticker certainly tells you when the motor was made... obviously the date at which it was installed in the JBE will be later.
I don't get the impression these were ever terribly high quality. They have squared off edges and the glue holding the sections together often deteriorates, with visible bubbles.I spent a long time trying to get a new clear lid to replace the original smoked lid on my JBE 3001. Eventually I ended up at The Fraser Company - The lid was made to measure and was not cheap, but far better than anything else I found and the company's service comes highly recommended (see the right hand picture). You can find the company here - CLICK HERE
While the acrylic plinths tend to resist damage, with the exception of minor surface abrasions, the slate plinths are very prone to marks, discolouration and chips. The slate plinths of the Series 3 have a chamfered edge and corners are particularly prone to getting chips and even on the long edges damage is not uncommon. Small scratches and tiny nicks in the edges can be removed using wet and dry paper, used wet. Use a very fine grade of paper to avoid adding swirl marks into the slate, but good results can be achieved. Once sanded you'll want to refinish the slate, and I've found a light oil works best, but will need repeated buffing to get rid of any surface tackiness.
Like many turntables (and presumably other components) from the time, the JBE uses fixings that are neither metric, nor familiar imperial sizes. All fixings on JBEs (for items such as the hinges, feet and SME tonearm mountings are a BA (British Association) thread. For the SME mounting screws on a slate deck, the size is 6BA and if you need a new threaded insert on the plinth itself, these can also be bought and then glued in place. While it is possible to buy these fasteners in mild steel, I've found them easier to source in brass. A great company is GWR Fasteners, which typically also sells packs on eBay.
CONTROL BOX REPLACEMENT
It is becoming increasingly common for JBE decks to be advertised without their control box, which has either been lost in storage or catastrophically damaged. It is possible to build a new unit from scratch, as I've had done. Others have built them with the power supply being part of the box, as per the original units, but the person who built mine used a mass produced power supply more usually found with computers etc, which was then plugged into the replacement box which had controls for speed selection and adjustment etc. Here are some images of the unit I had built (using a case bought from CPC Farnell I think). Here is also the circuit diagram I found online... this includes the onboard power supply, which was stripped out of the unit built for me. Please do NOT attempt to build your own unless you have suitable experience and using this diagram as a basic guide is done so completely at your own risk! The control knobs are simply bought online and the speed rating was engraved in by our local Timpson shoe repair shop!
MOTOR SPEED VARIATIONS
Several owners have now told me that their Series 3 turntables suffer from speed variations, sometimes mild and sometimes catastrophic. There does not currently appear to be any definitve answer to this problem, although it increasingly looks likely that the problem may come from the JBE's separate control unit, rather than the motor itself.
My own JBE 3001 suffered from this and the issue was indeed in the control box. The 18v regulator transistor was faulty, causing the speed issues. This was replaced while, at the same time, bringing the earthing up to modern standards for safety.
Series 3 owner Michael Trei points to the capacitors in the control box being the likely culprits for this issue, and these can be replaced with modern equivelents. If you are considering buying a Series 3, at least ask about any speed issues the existing owner may have experienced. If possible, test the turntable before you buy.
MICRO SEIKI FEET
Earlier JBE turntables have Micro Seiki feet which are very prone to deteriorating and falling apart. You will also come across a different type of foot which appears to have a metal construction and certainly looks more sturdy (see pic below right). I suspect this was a later development.
MICRO SEIKI FEET REPLACEMENT
The existing Micro Seiki feet are easy to remove if they have become damaged and it is possible to find various substitutes on eBay. However, there are a couple of very smart and effective replacements.
The first is offered by Track Audio (see the left gallery below) and the second by Kridon Panetelli (see the right gallery below). I've used Kridon's feet on my own deck and they not only look superb, but immediately offered a significant sonic improvement.
Quite a few people question the wisdom of the JBE 6-disc platter. Brian Voce contacted me with the following experiment...
"I'm currently experimenting with a 15mm acrylic platter and arm board (I had these custom turned by a local engineer). First impressions are promising... the sound is more detailed and 'dimensional', cleaner (if leaner), more even and neutral, and bass clearer. You can better hear the 'stringy' quality to bass guitars for example. Speed stability is much better too, piano sounds more 'secure'. On the downside there seems to be less snap to the bass which is a drawback but I think an aluminium arm board and directly clamping the arm to the slate chassis could cure this. I.e. The arm is securely clamped underneath directly to the slate. (There were certainly improvements in this area when I clamped the Rega this way rather than using an arm board). The extra thick arm board precludes this at the moment but I'm getting a custom made 'arm nut' made to allow this."
These suggestions are kindly made by Allister Hardwick, and could possibly provide a cure for the JBE motor stability issues several owners have suffered...
1. Replace all the smoothing capacitor(s) in the black box with brand new audiophile grade one(s). But only use like for like values in terms of dc-voltage and farad values.
2. Un-solder each solder point, one-by-one and re-solder with modern 21thC silver-solder (eg Mundorf).
3. Change the ac/dc bridge rectifier unit for modern audiophile grade unit.
4. Un-screw the transformer and insert small anti-vibration 3mm thick pad underneath and re-screw up tight.
5. By pass the (utterly redundant) voltage selector switch with a wire bridge.
6. Change the variable - potentiometers (but check values) for new ones.
7. Change mains fuse for a MCB unit or remove fuse all together (but risky!!!).
8 Swop industrial fuse for audiophile grade one, but check amp value.
9. Drill holes in base for screws+cone feet... eg Russ Andrews mini/small ones (3 or 4).
10. Anti-vibration 3mm pad underneath large smoothing capacitor.
11. Other things eg completely replace all industrial grade copper wiring with silver wire plus teflon tubing as the insulation.
13. Replace old pvc/copper mains cable with modern teflon/silver plated copper mains cable plus Rh/AU plated IEC socket on back of PSU box unit.
14 Or... you could try to split the AC to DC section into a new (box from Maplins) separate box ie Transformer+rectifier+smoothing cap(s) into one new box with a female XLR socket(front) + IEC male socket(back). Then from the JBE3 acryllic-black box feed out the two DC wires to a male XLR type plug. Thus you now have 2 boxes for the PSU and the 5-way power out lead still exists from the 1st PSU box to the JBE turntable.
Plenty of scope for improvement to get speed stability to near perfect.