Jelco SA-750D - mounting confusion!

[prsjnb]

Whilst researching the possibility of using a recently acquired 750D as a 'drop-in' replacement for an SA-250st on my Heybrook TT2, I came across a number of threads in which the majority view seemed to be that the mounting information supplied with the arm and listed in the VE database was incorrect. As there seem to be a number of satisfied users of the 750D on the AOS forum, I am seeking input on the the correct mounting distance to use.

On a related note, any thoughts as to which of the two arms mentioned would be a better match for a Technics SL-150, when paired with a Denon DL-110, Nagaoka JT-322 (NOS with original stylus) or AT-115E?

Many thanks in anticipation,

Jon

[Ammonite Audio]

The spindle-pivot distance for the SA-250ST is different to the SA-750D, by around 4mm, so they are not strictly interchangeable. The correct mounting distance for the SA-750D is 214mm; for the SA-250ST it's Linn-standard 210/211mm. See http://www.jelco-ichikawa.co.jp/products/tonearm.html#spec01 .

As to which Jelco is better, that rather depends on whether you need a removable headshell, and which cartridge you'd like to use. The SA-750D is a heavier arm that would definitely be the better bet for use with low-compliance MC cartridges, eg a Denon DL103 which really likes to see a bit of mass to come on song. For most MM cartridges, the cheaper and lighter SA-250ST may actually be better sounding - Sound HiFi always used to say that it was a better arm, being rather more rigid, but that really does depend on what it's being used with and preference for a fixed or removable headshell.

Both tonearms suffer from the same poorly designed mounting collar, which makes consistent setup and azimuth alignment rather tricky.

[prsjnb]

In the absence of any claims to the contrary, and as 214 mm is what I had always understood the correct mounting distance to be, I'm mightily reassured by your post, Hugo.

Thanks to the AOS forum, I am aware of the mounting collar issue and already possess one of your excellent replacements which is currently deployed with the SA-250ST. Moreover, I fully intend to purchase an improved, Mk. II version for use with the SA-750D :D

Your comments regarding cartridge matching are much appreciated and duly noted.

The removeable headshell of the SA-750D was the deciding factor in my deciding to buy one as I have 'collected' a number of different cartridges in recent months and I'm keen to take them for a spin.

Jon ;)

[worrasf]

As an aside and having been a very happy user of a 750D on an SL1210 you will have problems setting up some cartridges to Baerwald of Lofgren.
However, the OEM Jelco null points of 59.1 & 112.5 work with all the cartridges I have tried.

http://www.vinylengine.com/library/jelco/sa-750d.shtml

[Andrei]

As an aside and having been a very happy user of a 750D on an SL1210 you will have problems setting up some cartridges to Baerwald of Lofgren.
However, the OEM Jelco null points of 59.1 & 112.5 work with all the cartridges I have tried.


Ahhhhh. I did find it tricky in setting up my 750D. I am definitely going to give it a go with the supplied Jelco mounting template.