LAD tonearm (Jelco 370h?) armboard choice...

[synsei]

I am wanting to fit a LAD/Jelco tonearm to my Techie and have found out via Vinyl Engine that although the LAD is based on Jelco's 370h, the LAD version shares the same geometry as a Jelco 750D. I have it fitted to one of Shuggies excellent collars. So, does that mean I need to be looking for a 750D armboard?

[mido]

Dave.

Not necessarily according to these guys.

http://www.soundsupports.com/page16.htm

If you scroll to the bottom to the Jelco plate, they say it is not suitable for the LAD.

Perhaps you could mail them, they should be able to advise.

[mido]

Been thinking about this and am rather curious about it as the Shuggie collar was to be my next purchase. One would think that if your arm fits the Shuggie collar then it would fit the Jelco armboard. However, I was advised to get the Linn armboard for my Jelco SA-250. I e-mailed Shuggie and he said that the collar fits all Jelco arms, but will it fit the Linn armboard? :scratch:

[mido]

Ok, I think I understand now.

The collar should fit both of these plates, the differences between the plates is nothing to do with the fittings, but the design and geometry of the arm.

So, I guess if your LAD is the same geometry as the 750 arm then it would be logical that you would require an armboard plate that was designed for the 750, yet they say on that site that their one is not suited to the LAD :scratch:

[synsei]

Probably because the LAD collar is far smaller than that used for the 750D and presumably other Jelco arms. The LAD fits perfectly into Shuggies collar btw ;)

[synsei]

I notice there have been 76 views of this thread, anyone else want to chip in about which armboard I should choose?

[Ammonite Audio]

Been thinking about this and am rather curious about it as the Shuggie collar was to be my next purchase. One would think that if your arm fits the Shuggie collar then it would fit the Jelco armboard. However, I was advised to get the Linn armboard for my Jelco SA-250. I e-mailed Shuggie and he said that the collar fits all Jelco arms, but will it fit the Linn armboard? :scratch:

A Jelco mounting collar will not fit a board cut for a Linn arm, since the central hole and bolt arrangements are different. Also, the correct mounting distance for Linn arms and Jelco arms are not the same, so you do need a board cut and configured correctly for the Jelco. See the tonearm database on Vinyl Engine for exact figures.

I think that the 'problem' identified by Dave with Sound Supports and what they state on their website is simply that the LAD collar is completely different to the normal Jelco collar, eg it's smaller with different mounting bolts. When you see the LAD and Jelco collars side by side, it's clear that they are quite different. But, the arms are fundamentally the same. The incompatibility refers to the LAD mounting collar, not the arm itself.

I gave Dave one of my collars, which means the LAD arm can fit a Sound Supports board, once the upper plate of that board has been opened up by 1mm all round to accept the slightly larger diameter of my collar.

I hope that makes sense.

[synsei]

Excellent Hugo, thanks for that. I hope you are well :)

I have removed the arm from the LAD which was far easier than I was expecting, it is the first time I have attempted such a thing btw ;)

[mido]

A Jelco mounting collar will not fit a board cut for a Linn arm, since the central hole and bolt arrangements are different. Also, the correct mounting distance for Linn arms and Jelco arms are not the same, so you do need a board cut and configured correctly for the Jelco. See the tonearm database on Vinyl Engine for exact figures.


Hi Hugo.

I was advised to get the Linn armboard here for for my Straight armed Jelco 250?

http://www.soundsupports.com/page16.htm

It says "For fitting all Linn arms at the correct geometry and VTA (Vertical Tracking Angle) Also suitable for the straight armtube Jelco models."

I have been using it for about a month now.

Have I bought the wrong thing then? Is the mounting distance incorrect?

And will your mounting collar not fit it? The standard Jelco collar fits fine.

Thanks in advance,

Frank

[Ammonite Audio]

Hi Frank

I have given you duff information earlier in this thread regarding the Jelco SA-250ST and the Sound Supports Linn armboard; and have replied to your PM. You have already confirmed that the Jelco collar does indeed fit the Linn bolt hole arrangement, so that's OK. My earlier duff information was based on the Linn mounting collar needing a larger diameter hole, but in this instance it does not matter with a smaller Jelco collar as the bolts still secure it.

For others, the question here is specifically for the straight arm SA-250ST, which has a shorter mounting distance to the SA-750 that most people use around here. That mounting distance is 210mm against 211mm for a Linn arm, so the Linn plate is more or less OK for the SA-250ST, but most definitely not for the S-Shaped SA-250 or the SA-750 which have a mounting distance of 214mm for the 9" versions.

Frank, your potential problem using one of my collars with this particular armboard is that a single-plate armboard like yours may set the arm too high to achieve correct VTA without having to use thicker mats or headshell spacers. In my experience, you do need an armboard with a sunken centre section for this reason. Sound HiFi used to sell a very good one, but I would use one of these - http://www.ebay.co.uk/itm/Jelco-SA-250ST-Armboard-Plate-Technics-SL-1200-1210-MK2-MK3-MK4-MK5-M5G-MK6-/151001743056?pt=Turntable_Parts_Accessories&hash=item232867bed0 - which allows the sunken section to be lowered even more if required, using washers/spacers, so you get the necessary flexibility.

The key here is to look at your SA-250ST as it's currently set up on your Technics, and measure the distance between the top of the standard Jelco collar and the bottom of the arm's lift/lower device plate. If that distance is less than 5mm, then you will have a problem because my collar is 5mm taller than the original. That problem is not insurmountable, but you do need to be aware of it.

I hope that helps and sorry for the duff/mixed information.

[mido]

Ok, now I am completely lost. :scratch:

I currently use a mat that is 3mm thick and the distance that my arm is raised from the collar is approximately 5mm at the back. If your collar adds 5mm, then wouldn't it follow that the VTA would be about right if the arm is set at its lowest point using your collar?

I know that most people say that the arm should be set horizontal to the record, but in my set up this just sounds wrong. Perhaps this is something to do with my particular cartridge, maybe most sound best with the arm horizontal, but if my arm is set like that the sound is dull, muddled, bass heavy and just does not sound right.

Or, perhaps I am doing something else wrong!? :confused:


Sorry Dave, if I have hijacked this thread somewhat. :o

[Ammonite Audio]

Hi Frank

You're fine. You already have 5mm clearance available at the arm pillar with the standard collar, so all this means is that, with my custom collar and its extra 5mm of height, your arm will simply rest on top of the collar to achieve precisely the same VTA as before.

VTA varies between cartridges because the stylus tip is not necessarily attached at a standardised angle, so the horizontal arm guide is just that - a guide and starting point. Also tracking weight has an effect because the cantilever suspension is compliant and small changes there are equivalent to much more obvious changes in arm height at the pillar. You are doing the right thing by using your ears to find the best setup.


Ok, now I am completely lost. :scratch:

I currently use a mat that is 3mm thick and the distance that my arm is raised from the collar is approximately 5mm at the back. If your collar adds 5mm, then wouldn't it follow that the VTA would be about right if the arm is set at its lowest point using your collar?

I know that most people say that the arm should be set horizontal to the record, but in my set up this just sounds wrong. Perhaps this is something to do with my particular cartridge, maybe most sound best with the arm horizontal, but if my arm is set like that the sound is dull, muddled, bass heavy and just does not sound right.

Or, perhaps I am doing something else wrong!? :confused:


Sorry Dave, if I have hijacked this thread somewhat. :o