Jelco TK-850M 10″ Tonearm. We are pleased to stock Jelco’s new range of tonearms. The TK-850 and TK-950 series sit above Jelco’s previous top-line SA-750 models and employ a ‘knife edge’ vertical bearing system, with conventional ball race horizontal bearings. Over the years, knife-edge bearings have tended to be sneered at by audiophiles, but actually there’s nothing wrong with them, when properly designed and implemented. These arms are properly implemented and feel a definite step up in terms of finish and handling. Jelco have built their reputation for fine finish and quality at reasonable prices, and these new arms build on that very nicely.
So, what’s the benefit of a knife edge bearing? The arm tube does feel loose when first handling it, but be assured that this is part of the design – the bearing design is captive so it won’t all fall apart and the arm tube sits very firmly on the knife edges under its own weight and there is no slack in the bearing and no risk of chatter when it’s actually playing. There’s nothing to go out of adjustment either. The TK series arms come with a two piece counterweight which has a sliding mass ring, meaning that the one weight can cater for a broad range of cartridge mass.
Jelco have very slightly adjusted the geometry of the new TK series arms, but importantly the spindle-pivot mounting distance for the TK-850S remains 214mm, and with plenty of adjustment scope at the headshell, you will be able to align a cartridge properly without problem. The good news about Jelco’s slight changes to geometry is that an Ortofon SPU with integrated headshell fitted to the TK-850S will be aligned correctly to Baerwald/Loefgren A.
What about how it plays music? We have compared the old SA-750D with the new TK-850S, using a new Technics SL-1200GR turntable, fitted with our own Ammonite Audio machined modular Technics armboard. the SA-750D is a fine arm and always will be, but immediately the new TK-850S sounds more graceful, more colourful, more dynamic and more musically engaging. It’s a definite step up, and for existing 9″ Jelco owners wanting to look at sonic upgrades, the TK-850S is a logical choice at a reasonable price. The new TK-850S is a direct drop-in replacement for an older SA-750D or SA-250 arm (not the straight tubes SA-250ST, though). Also good news is that the TK-850S fits neatly and without any problem under a Technics SL-1200 turntable’s dust cover.
|Bearing System||Knife Edge|
|Effective length||256 mm|
|Mounting Distance (Pivot-Spindle)||240 mm|
|Tracking error angle||＋1.44° －0.58°|
|Horizontal sensitivity||30 mg|
|Vertical sensitivity||30 mg|
|Suitable cartridge weight with head shell||17~35 gr|
|Effective mass||13.0 gr|
|Range of height adjustment||38~60 mm|