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.
MICRO ABSORBER FEET
Earlier JBE Series 3 turntables have Microabsorber feet which I'm told can sometimes deteriorate and fall apart. Those on my own JBE 3001 are fine (see pic below left), but 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.
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, leaving the cover looking a bit scruffy.
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 occasionally suffers an initial variation in speed, usually after a longer period of no use.
Seies 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.
If I can get a definitive answer to this problem I will obviously post something here.
MICRO ABSORBER FEET UPGRADE
The existing Microabsorber feet are easy to remove if they have become damaged and it is possible to find various substitutes on eBay. However, by far the most bespoke and high quality upgrade I've come across is made by Track Audio run by Mike Butler. By complete coincidence he has developed some new isolation feet which he demonstrates... on a JBE Series 3! These are high end components made in stainless steel and with proven methods of isolation, but they do come with a price to match... £395. You'll find them reviewed on the Adventures In High Fidelity Audio website, where main man Neil has allowed me to use the images you see here. Cheers Neil.
GENERAL UPGRADE OPTIONS
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.
CONTROL BOX REPLACEMENT
Another option to try and cure the speed issues (or if you find a JBE without its control box) is to build your own. This was successfully done by Kevin Minns using the original wiring diagrams for a Technics SL2000 turntable (see pages 6 and 7 in the pdf manual below), which used the same motor as the JBE. He used a Maplins PSU for the 18 volt power supply (part no. L49BL).