Custom Arm Mounting Collar for Jelco SA-750 - essential for setting correct azimuth

[DSJR]

I believe that Hugo looked at the simpler Linn way of having a bit scooped out of one side of the hole, leaving two vertical "edges" to act as stable mounts, the piller held in place with one bolt as near as near midway up as possible. Linn called it an "engineers' clamp." This would give a three-point mount as near as possible and at least the pillar wouldn't be able to move.

[Ammonite Audio]

I believe that Hugo looked at the simpler Linn way of having a bit scooped out of one side of the hole, leaving two vertical "edges" to act as stable mounts, the piller held in place with one bolt as near as near midway up as possible. Linn called it an "engineers' clamp." This would give a three-point mount as near as possible and at least the pillar wouldn't be able to move.

I did look at that, since the original Jelco collar has a similar arrangement that does not work because the collar otherwise does not hold the arm pillar correctly (unlike the Linn collar for my Ittok LVII which is an object lesson in how to do things properly). In the end, a precisely machined hole was so snug a fit that anything more elaborate was unnecessary.

[ninja]

If anyone decides to sell or build one please PM me.

[Mike_New]

Hi Ninja,
I machined up my version of a mounting collar for the Jelco in mid august. it was commisioned by a guy in Fort Collins CO. But now that I am reminded, I never did get a reply from him as to how it performed.
I will email him now.
If there are many people out there who still require one of these then I will set about machining some. I use a precision hole and two 4mm securing screws at 90degrees. The collar can be made in Brass or Alluminium. The screws are actually Hex socket heads which protrude from the collar and permit tightening with the fingers first to ascertain the requred height.
The hex screws can then be clamped up using a Hex Wrench.

[ninja]

Thanks Mike,

I am interested if the price is about the same "level" as before.

[Mike_New]

ninja,
I have just had a reply from the guy in the US, he says that the collar works fine and that the two screws allow for secure adjustment and clamping. He did give me a couple of thing to improve.
However I got an email from Hugo yesterday saying that he was intending to restart the making of collars. There is no future in two of us doing it, so I have left it to Hugo to do what has to be done.

[Ammonite Audio]

I do not wish to tread on Mike's toes here - his collar design is different to mine and I like to think that there's room in the market for both. That said, I have had a preliminary conversation with a potential retail partner for my collars. If that proves feasible, then it will be much easier for anyone wanting a collar to buy one whenever they wish, as opposed to waiting for me to produce a batch. My collar design is exactly the same as the last lot that I did, eg in CNC-machined aircraft grade aluminium, vapour blasted and brightened/anodised for a durable finish. This time, I can look at doing some of the collars in black anodised finish, since I know that some customers did want this before.

[ninja]

Thanks Mike and Shuggie, I'm still interested and I am not in a hurry, so, I can wait.

[DSJR]

Silly question to most of you Jelco owners, but is one of the 750's a drop fit into a Rega hole (suitably modified)? I only ask as it would appear that the standard 750 as used on the Techie is similar to the Linn-length arms, although I'm not sure if the 10" version wouldn't be too long?

[Ammonite Audio]

Silly question to most of you Jelco owners, but is one of the 750's a drop fit into a Rega hole (suitably modified)? I only ask as it would appear that the standard 750 as used on the Techie is similar to the Linn-length arms, although I'm not sure if the 10" version wouldn't be too long?

No, it would not just drop in - the mounting distance is totally different from either Rega or Linn arms, whether you are looking at the 9" or 10" Jelco (see the Tonearm Database over at Vinyl Engine). Also, the mounting hole is a different size compared to any Rega based arm.