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.
What is Dynamic Balancing? The TK-950L allows you to set vertical tracking force (VTF) by either adjusting the counterweight, or by using a spring mechanism to conveniently dial in the required VTF. Look at the pictures and you will see a horizontal knob sticking out of the side of the main bearing ‘drum’ and that is the calibrated dynamic downforce adjuster. Does that mean better sound over the simpler static balancing of te TK-850? Probably not – this is largely a matter of convenience and ease of use. Do bear in mind that the TK-950 bearing ‘drum’ is slightly taller than that of the TK-850 arms, so it may not fit under the lid of some record players – please ask and we’ll do our best to advise.
Jelco have very slightly adjusted the geometry of the new TK series arms, but importantly the spindle-pivot mounting distance for the TK-950L 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-950L will be aligned to within 0.1 degree accuracy.
The Jelco TK-950 arms all come with Jelco’s SG-1 digital Stylus Pressure Gauge – this is a neat little thing that’s a much better design than the usual cheap Chinese gauges sold under a number of banners. The balance plate of the SG-1 really does sit at normal record height, and since VTF usually changes with armtube angle, that does actually matter.
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 System||Knife Edge||Knife Edge|
|Tracking Error Angle||+1.45° – 0.85°||+1.96° -1.03°|
|Suitable Cartridge Weight (with Headshell)||17-35g||17-35g|
|Counterweight Type||2 piece adjustable||2 piece adjustable|
|Range of Height Adjustment||38-60mm||38-60mm|
|Headshell Type||Jelco HS25||Jelco HS25|