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Need a AR-XA measurement please...

It's coming together very nicely tho' I'm still a bit concerned with the offset not being compensated off the other side with a damped counterbalance mass. Theoreticals and all that, it's the little things that add up to a given result.
 
I took your suggestion to heart and have a 1.5 pound brass weight to add near the center of mass of the t-bar once the springs arrive. In the first photo I posted today you'll see a routered area where I can overhang the weight.
 
Be sure to use a broad area lossy coupling like my mod for the T-60, it should do good all around to neutralize the substructure resonances and possibly some of those of the arm. You do want to comp the torquing the offset mounting puts on the long axis of the substructure.
 
Thanks fellas! I'd call it a work in progress, not so sure about the work of art except for the fine piece of burl. Remains to be seen (or heard) whether it sounds as good as it's looking.

Marc, I polished the spindle as best as I can with 400 and 1000, please let me know how I can order the 3 and 1 micron papers from you. I emailed but didn't get a reply.
 
jimreeves said:
Thanks fellas! I'd call it a work in progress, not so sure about the work of art except for the fine piece of burl. Remains to be seen (or heard) whether it sounds as good as it's looking.

Marc, I polished the spindle as best as I can with 400 and 1000, please let me know how I can order the 3 and 1 micron papers from you. I emailed but didn't get a reply.
Click to expand...

give me an address via email, and i'll send it to you.........just as soon as you give me the stud size so I can get the perches done. :yes:
 
jimreeves said:
Oh yeah, I still have to make a arm rest too. Here's a closeup of the arm...

Burl17.jpg
Click to expand...

Truly exceptional idea and design. A lot of hard work though.

Simply great :thmbsp:
 
Finishing up!

With the gracious help of AK member Marcmorin I've reached the end of this project build. The Linn springs I ordered from England showed up finally, so I could set the balance with Marc's jig and the brass balance weight I'd ordered. This was needed to offset the tonearm platform which is offset to the AR t-bar as you can see.

jiglevel2.jpg


The 1.5 pound brass weight is positioned to give equal compression of all 3 springs with t-bar, platter and tonearm platform level. Per Pio's suggestion the weight is only attached with adhesive rather than screwed to the t-bar.

brassweight.jpg


I removed the innards from the jig and put everything back into the plinth with Marc's handy perches for the Linn springs and adjusted for approx. 70% compression per his instructions.

Burlbottomassy.jpg


Here you can see the rough cut HDPE 'base' I attached to house the switch and the terminal block. There's enough clearance to slide fingers under it to flip the switch and it remains hidden. I stripped a length of cable shielding to offer some RF protection for the tonearm leads and made the terminal block from a strip of black laminate with RCAs sourced online and ground from Lowes.

terminalblock.jpg


It's all set up again and singing as I type. The black background and depth of image is incredible! The SAE 900LT has never sounded as tight, focused, wide and DEEP as it does now!

ARBurl2.jpg


Again, thanks to Marcmorin for his patient guidance with this unusual project. He made all the difference in getting this one-off sounding so great! :banana:
 
jimreeves said:
With the gracious help of AK member Marcmorin I've reached the end of this project build. The Linn springs I ordered from England showed up finally, so I could set the balance with Marc's jig and the brass balance weight I'd ordered. This was needed to offset the tonearm platform which is offset to the AR t-bar as you can see.

jiglevel2.jpg


The 1.5 pound brass weight is positioned to give equal compression of all 3 springs with t-bar, platter and tonearm platform level. Per Pio's suggestion the weight is only attached with adhesive rather than screwed to the t-bar.

brassweight.jpg


I removed the innards from the jig and put everything back into the plinth with Marc's handy perches for the Linn springs and adjusted for approx. 70% compression per his instructions.

Burlbottomassy.jpg


Here you can see the rough cut HDPE 'base' I attached to house the switch and the terminal block. There's enough clearance to slide fingers under it to flip the switch and it remains hidden. I stripped a length of cable shielding to offer some RF protection for the tonearm leads and made the terminal block from a strip of black laminate with RCAs sourced online and ground from Lowes.

terminalblock.jpg


It's all set up again and singing as I type. The black background and depth of image is incredible! The SAE 900LT has never sounded as tight, focused, wide and DEEP as it does now!

ARBurl2.jpg


Again, thanks to Marcmorin for his patient guidance with this unusual project. He made all the difference in getting this one-off sounding so great! :banana:
Click to expand...

Beautiful table my friend. When tuned properly, it's hard to beat an AR for imaging and blackness of background.
Glad you allowed me to be part of this project.
 
What would anyone here suggest that I use to polish the platter? If I do, will it remove a coating that would need to be reapplied?
 
If it doesn't actually need it I wouldn't do it. Cleaning with a mild detergent and water (definitely not alcohol or phosphated liquid super-cleaners!) followed by a rinse is as far as I'd go with one that is otherwise cosmetically presentable.
 
jimreeves said:
It's tolerable for sure, just has a few spots that have 'tarnished"?
Click to expand...

The outer rim, or the top surface where the original AR mat embedded itself into the aluminum?. On the rims I start with one of those sponge filled plastic pot scrubbers with an equal amount of dish soap and comet. Makes a nice polishing paste. Too bad pearl drops tooth polish is no longer on the market. If you go with car polishing compound as a second step, go back to the plastic sponge again with just dish soap.
 
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