Jelco TK-850L 12″ Tonearm


Jelco’s brand new TK-850S tonearm, which has a ‘knife edge’ vertical bearing system.  Quite a bit more ‘grown up’ and musical compared with older Jelco SA-750 arms and a logical upgrade from those arms.  All new Jelco tonearms bought from us come complete with one of our improved mounting collars worth £51, at no additional cost.

In stock

SKU: JEL-TK850L Category:


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 the, 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.  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-850L remains 290mm, and with plenty of adjustment scope at the headshell, you will be able to align any cartridge properly without problem.  The good news about Jelco’s slight changes to geometry is that, according to our calculations, an Ortofon SPU with integrated headshell fitted to the TK-850L will be aligned to within 0.1 degree accuracy.

What about how it plays music?  We have compared the old SA-750D with the new 9″ 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-850 arm 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-850L is a direct drop-in replacement for an older SA-750L or SA-250L arm.


Bearing SystemKnife EdgeKnife Edge
Balancing ForceStatic Static
Effective Length303mm232mm
Spindle-Pivot Distance290mm214mm
Offset Angle17.7°23.75°
Tracking Error Angle+1.45° – 0.85°+1.96° -1.03°
Horizontal Sensitivity30mg30mg
Vertical Sensitivity30mg30mg
Suitable Cartridge Weight (with Headshell)17-35g17-35g
Counterweight Type2 piece adjustable2 piece  adjustable
Range of Height Adjustment38-60mm38-60mm
Headshell TypeJelco HS25Jelco HS25


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