Am a materials scientist and I would think that the advances in CNC controlled machine tools and analytical tools has the largest effect in today's bearings of all sorts. Both have led to the optimization of materials and machining. Jelco makes a point of stating that their knife-edge bearings are fitting by hand, which seems to fly in the face of many advances. That said, I'm giving some serious consideration to a TK-850L.
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SME M2-9R vs Jelco TK-950S
- Thread starter watchnerd
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watchnerd
Grand Contributor
- Thread Starter
- #42
I ended evaluating both the M2-9R and TK-950S (which uses knife edge plus springs).
The TK-950S had a number of things I liked better than the SME (anti-skate dial vs string, feel of the cueing lever), but I ended up getting the SME because I find it easier to align and I preferred a the way SME does azimith adjustment (at the collar/arm, as opposed to on the headshell like Jelco), in case I ever decide to pull the trigger on an SPU cart.
I can understand that. I've pretty much decided to phutz with my 3009 II (unimproved) rather than go new. That, plus SME's pricing since the company was sold is insane ($3100 for the formerly $1700 TA, for instance). As stated in the review of their newly released 301 TT 're-issue', the only thing wrong with it is the price ($20K+). Yes, an SPU may be my next cartridge purchase. Either an SPU Century or A95. But, I've got about 5-6000hr of stylus to wear out first, so will be a while.
Jaimo
Active Member
A common complaint with the Jelcos is the loose fitting base collar with a single grub screw used to fix the arm in place. Tightening the screw tilts the arm slightly, and also marks the arm pillar. There are at least two companies that have attempted to fix this Azimuth related issue with better designed bases. I just purchased a base collar from the now out of business TTW company in Toronto for my Jelco SA 750LB arm.
From the pics posted, it looks like the new generation Jelco arms use the same base collars as the SA750L arm and could possiblly have the same issue. There are also aftermarket VTA adjusters that enable finer VTA adjustment than the standard Jelco Design.
Take a look at the various discussion threads on DIY-Audio that talk about using a digital microscope to measure and adjust the Stylus Rake Angle. It seems that cartridge QC is not up to snuff and there is a great deal of SRA variability from cartridge to cartridge.
From the pics posted, it looks like the new generation Jelco arms use the same base collars as the SA750L arm and could possiblly have the same issue. There are also aftermarket VTA adjusters that enable finer VTA adjustment than the standard Jelco Design.
Take a look at the various discussion threads on DIY-Audio that talk about using a digital microscope to measure and adjust the Stylus Rake Angle. It seems that cartridge QC is not up to snuff and there is a great deal of SRA variability from cartridge to cartridge.
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I haven't looked at the discussion but will say one of the most fundamental problems of LP playback is consistency from cartridges.
They are small and bonded and use polymer suspensions/dampers.
Frankly this means variability of stylus alignment and temperature dependance are pretty well inevitable.
The more "sophisticated" a stylus shape the less tolerant it will be of misalignment.
The Ortofon Replicant I have mainly used for decades looks incredibly sensitive to the tintest misalignment if the large perspex model of it in which my 3000 mk2 was delivered is anything to go by.
Hand made cartridges probably vary the most. OTOH they are mainly very expensive so out of line units can be thrown away and absorbed in the price since cartridges contain very cheap bits assembled into very expensive products
exotic cantilevers and stylus profiles excepted.Plenty of scope for jewelled or exotic wood bodies in the price...
OP
watchnerd
Grand Contributor
- Thread Starter
- #47
I haven't looked at the discussion but will say one of the most fundamental problems of LP playback is consistency from cartridges.
They are small and bonded and use polymer suspensions/dampers.
Frankly this means variability of stylus alignment and temperature dependance are pretty well inevitable.
The more "sophisticated" a stylus shape the less tolerant it will be of misalignment.
The Ortofon Replicant I have mainly used for decades looks incredibly sensitive to the tintest misalignment if the large perspex model of it in which my 3000 mk2 was delivered is anything to go by.
Hand made cartridges probably vary the most. OTOH they are mainly very expensive so out of line units can be thrown away and absorbed in the price since cartridges contain very cheap bits assembled into very expensive products
Plenty of scope for jewelled or exotic wood bodies in the price...
Additional note on the Replicant:
Ortofon says it only has a 1000 hour life before degradation begins.
"With proper care we find that up to 1000 hours is possible without degradation of performance. The stylus does begin to exhibit changes after 1.000 hours, but the stylus life as a whole is expected to top 2.000 hours."
https://www.ortofon.com/hifi/products/hifi-cartridges/mc-anna/diamond/
This seems quite a bit lower than the 3,000-5,000 hours quoted for other carts with simpler styli.
I had never seen such a life quoted before, certainly not when I was in the business 40 odd years ago. 1000-2000 has always what I have considered normal. It will presumably depend on the actual rubbing area which will depend on the shape and vtf so it is difficult/impossible to know the actual contact area of the various shapes.
I haven't used a stylus more than 1000 hours (on purpose anyway)
D
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BTW: SME has just left the seperate tonearm business …
https://sme.co.uk/2019/12/03/sme-product-announcement/
https://sme.co.uk/2019/12/03/sme-product-announcement/
Shame, SME are one of the few arm makers with the bearings in the right place (though not on all models).
