Magna Audio's custom-made counterweight balance and armboard service!

[Magna Audio]

Hi all,
Many thanks for the kind words and great to hear the ebony boards are doing the trick. Thanks to Marco for re-instating the thread.
If you need a counterweight, armbase or tonearm board for SL-1200/10 let me know.
Re the polishing: You could always carefully polish the bits that are exposed A tiny over polish in the arm base would not hurt would polish off I would have thought.

Regards,
Steve

P.S. Must update the avatar pic with more recent exponential mid bass horns.

[Magna Audio]

Rob's. Note the extra post arm rest - This was a complete deck conversion - remove original arm and adapt to fit the new custom armboard.

[DonGraft]

Hello Steve!
I just bought a SL1210Mk2 with stock tonearm, a DL103 and a AT-LH18/OCC.
What counterweight do you recommend? Any spacer for the headshell?

Thanks in advance!

[Magna Audio]

Hello Steve!
I just bought a SL1210Mk2 with stock tonearm, a DL103 and a AT-LH18/OCC.
What counterweight do you recommend? Any spacer for the headshell?

Thanks in advance!

Hi,
That sounds like a headshell that could suit well. I don't know the exact weight of the AT-LH18. One info source is quoting shipping and item weight as the same - 18g which sounds quite a lot. The Sumiko is a bit lighter. The 103 is 8.5 grams. So combined ~ 26.5g. I guess that is too much for the standard weight?
A SPU is 30g.

If it won't balance with the standard weight (and form a physics / sound point of view, it's best with the counterweight as close to the pivot as possible) then a heavier weight is needed.

Best thing is to add some 2 pence pieces or Pound coins if you need lots of weight, and stick them on with Blutak to get it to what you need. Then weigh the lot - can be done on digital kitchen scales like the ones in my photos or even more accurately at the post office on their letter scales

I could then make you a brass one or for a fair bit more a Tungsten one to suit. The Tungsten is much more dense so can be fair bit smaller but costs a lot for the raw material.

I wouldn't think that you'd need more weight with a spacer in the headshell and the VTA adjuster on the arm should take care of most cart / headshell combos.

Regards,
Steve

[DonGraft]

Great.
I'll make some tests (as soon as the items arrive) and I'll let you know more details

Thanks!

[Magna Audio]

Great.
I'll make some tests (as soon as the items arrive) and I'll let you know more details

Thanks!

Good stuff.

[Magna Audio]

Here's an interesting little project and something a bit different.
Compression driver to horn throat adapters.
These are tapered at the correct angle to reduce from 1.5" to 1" for a 1" BMS compression driver.

In progress



They are basically a steel plate, welded to a short section of 2" steel pipe and then another steel plate welded on. The plates make the mounting flanges for the horns and compression driver.
The plates are turned to be circular and white resin fills the 2" pipe. This then turned out on the lathe to provide the throat adapter, a smooth progression from 1" to 1.5".

Here is the finished article painted up and bolted up to horn and driver.





These horns now form the upper mid channels in a 5 way system for domestic use but one that will also see high quality PA use.

Here is a pic of them strapped in place





One side of the full outfit

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[Magna Audio]

Back on to turntables. Here is a plinth and arm spacer project.

Birch ply cutout to fit Garrard 401 deck



Deck trial fit



Countersunk mounting to suit AN arm



Birch ply spacer to give correct VTA and nice range of adjustment


Test mounted



The mounting board and spacer are sanding / rubbed down to smooth / sealed and will now be painted in a textured finish matt black as requested. Further photos to follow.

[Tarzan]

That work looks stunning Steve!

[Magna Audio]

Here it is all done. Finish is as requested by the decks owner.
It's Dulux matt black vinyl, rollered on for a textured finish. That way it does not just look black but a bit charcoal - works really well with the deck and plinth.