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Jelco SA750 D optimal cartridge alignement

Hi,

I have just installed a Jelco SA750 D with an AT 150mlx on my technics SL-1210 using the TimeStep armboard. Spindle-Arm centre distance is 214 mm.
The mounting template supplied shows the stylus tip about 2mm behind the front of the headshell yet it is impossible to set any of the various null points if the stylus is put here. I have settled on the Jelco null points of 59 & 112.5 although vinylengine also lists different null points for Stevenson, Baerwald and Lofgren B. Is there any received wisdom that one is "better" than the other and why does the stylus point not match the OEM mounting template even when using the Jelco default null points?

Regards
Steve
worrasf
bpoletti
1,554 posts
 
According to the alignment calculator on VinylEngine, the Jelco recommended geometry puts the null points about an inch in from the outer adge and then just before the inner runout grooves. There are other geometries that will work with minimum changes.

I have a SA-750D and am looking at options. Some require a different headshell. The headshell for the Micro Seiki MA-505 (or compatible) would work well since there are no front or side lips to limit the cartridge position. I tried using that headshell and it works fine on the SA750D.
worrasf OP
8 posts
 
I have just ordered a custom MintLP tractor from Yip at mintlp.com specifically for 214 mm and am assured I can align my AT 150 MLX to Baerwald so am hopeful. FWIW this morning I installed my Astatic MF-100 in the Jelco - again to OEM null points and I am delighted with the result - tracks band 3 of HFN test disc no worries and sounding stunning.
Regards
Steve
vinyladdict
164 posts
 
I was at the center if the controversy over at AA (my username there is vynyltap).

I stand by my finding that the Jelco spec'd effective length is just flat wrong. Why they don't correct it is beyond me. For what it's worth, the AT-150mlx will align just fine as mounted via Baerwald.
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