vishalk
Active Member
Hahaha rubbing alcohol if its stuck with dirt and grime!
Yet another AR XA rebuild thread
- Thread starter Efvergren
- Start date
Hahaha rubbing alcohol if its stuck with dirt and grime!
vishalk
Active Member
Very tricky to do the mass balancing and requires patience! In fact I may just do mine again I'd like to hear how others have done it or the best approach.
Efver
New Member
On my table I got the XB-style tonearm, my brother got the XA-style. I noticed that my XB-tonearm have a longer pivot shaft/ spindle(right word?). The sub-platter spindles are the same lenght on both.
I've read that later XA used the XB tonearm, but shouldn't the sub—platter spindle need to be equally longer for the vta to work correctly on mine? The wells/spindle sleeves on the t-bar have the same outer measurements on both our t-bars.
I've read that later XA used the XB tonearm, but shouldn't the sub—platter spindle need to be equally longer for the vta to work correctly on mine? The wells/spindle sleeves on the t-bar have the same outer measurements on both our t-bars.
Efvergren
New Member
I did a paint job on my top plate with some car sprayvans. Primer, matte black and some protective lacquer. Turned out pretty nice I think. Now I really want to get started with the new plinth!
It was pretty hard to get an even coat, but a lot of wet sanding with 400 and 800 grit between the coats did a big difference.
It was pretty hard to get an even coat, but a lot of wet sanding with 400 and 800 grit between the coats did a big difference.
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This is one of the hundred times that we will miss Marc. He would have answered quickly and definitively.
I made an unscientific comparison of an old XA and XB arm shaft and pivot block and they seemed like the same height to me. The key is the distance from the bottom of the arm spindle to the pivot point, and to my eyes they seemed to be the same. I may be way off, and hopefully someone else more knowledgeable will chime in. But that is how it looked to me when you compared the pivot points and not just the length of the pivot shaft alone.
Efver
New Member
Yes, there is a difference from pivot to bottom of spindle:
Found this quote from Marc, aswell:
Seems weird that my table got this arm to begin with, don't really know what to believe!
My XB tonearm:
Shaft length: 8,75cm
Pivot to end of shaft: about 9,23cm
Sub-platter:
Steel shaft including ball end ca 5,4cm
Someone with an XA table and XB style tonearm might be able to check there measurements for reference. Would appreaciate it!
Found this quote from Marc, aswell:
Seems weird that my table got this arm to begin with, don't really know what to believe!
My XB tonearm:
Shaft length: 8,75cm
Pivot to end of shaft: about 9,23cm
Sub-platter:
Steel shaft including ball end ca 5,4cm
Someone with an XA table and XB style tonearm might be able to check there measurements for reference. Would appreaciate it!
Efver
New Member
About the plinth, will probably go with oak aswell. I have a luthier friend who will help/ advise on french polishing. About the measurements my initial thoughts were to copy the original plinths outer measurements. I have a pristine looking dust cover that might be practical to be able to use.
I want the top plate to sit flush, yes. Looked really nice on yours @vishalk
Would you like to share your thoughts on measurements?
Did you copy the original plinth and just added some height?
I want the top plate to sit flush, yes. Looked really nice on yours @vishalk
Would you like to share your thoughts on measurements?
Did you copy the original plinth and just added some height?
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So taking a good look at your parts table I find it very confusing, the top plate has holes as it was from a early two motor table but it has a hole for the suspension lock down screw which was from the XB tables, but guessing that’s from the 110-220v board. The subchassis has the lock down threaded hole and the thread hole for the XB cuing device. Has the XA arm rest and tonearm including the steel counterweight. As far as the plinth, hard to tell from the pic if it’s solid Walnut or walnut veneer or vinyl veneer. Dust cover is probably from an XA, AR logo on the XB cover was black so someone added the brass logo to the top of the cover, XA covers didn’t have the logo on top, only on the front of the plinth. The XB cover is slightly taller than the XA cover, about 6mm.
As far as designing your plinth, up to you on how you want it to look, height can be added since there’s barely room for mass loading the suspension.
As far as designing your plinth, up to you on how you want it to look, height can be added since there’s barely room for mass loading the suspension.
Efver
New Member
Interesting notes @sfrost
It sure has the plastic veneer. Serial XA284655, with inscriptions by it's original owner(?): 10/9-75, price 895 SEK(about 98USD in todays value).
Perhaps the AR's for export got assembled with spare parts? When did the XB arrive? Maybe my example was built in the transition period between the two.
It sure has the plastic veneer. Serial XA284655, with inscriptions by it's original owner(?): 10/9-75, price 895 SEK(about 98USD in todays value).
Perhaps the AR's for export got assembled with spare parts? When did the XB arrive? Maybe my example was built in the transition period between the two.
vishalk
Active Member
So i decided its time to recheck and readjust my mass loading with ideas i put past Marc, I bought some accurate mini weighing scales capable of 2000grams in 0.1 increments, did a quick setup on the dining table (so excuse the mess)
I wanted to see and check if i had equal loads and weight on the springs using them, i always felt that it wasnt balanced and that the tonearm had more bounce to it.
As you can see i was correct there is much more pressure near the tonearm spring, now my thoughts are that there should be equal loading across all three springs, if i set this up properly using the scales like this will allow me to do this.
I am actually going to do the whole mass balancing again using a different system and weights, this will also help Efver who will do this soon himself!
So guys i would love input into how you all have done or do your mass balancing and what i need to look out for.
I wanted to see and check if i had equal loads and weight on the springs using them, i always felt that it wasnt balanced and that the tonearm had more bounce to it.
As you can see i was correct there is much more pressure near the tonearm spring, now my thoughts are that there should be equal loading across all three springs, if i set this up properly using the scales like this will allow me to do this.
I am actually going to do the whole mass balancing again using a different system and weights, this will also help Efver who will do this soon himself!
So guys i would love input into how you all have done or do your mass balancing and what i need to look out for.
Efvergren
New Member
@vishalk Im curious to hear about your progress with the mass loading 2.0. Since last post I did a repaint of my top plate since I was not satisfied with my first attempt. Im still not hundred percent happy since the surface is a little bit uneven, but only in that area that will be covered by the top plate, so I think I will stick with this.
A customer just sent his AR table for some upgrades, very newer model XA, one I have not seen in the 40 years I have been working on these tables. Seems to be like yours, top plate is an XA but is painted like the XB. Has the XB subchassis with the Hole for the cuing device. Plinth is built like the XB with the same corner bracing. Has a XB arm rest. XA inner platter and power switch but on logo on the front of the plinth. Serial # XA 287248, box indicates it is an XA-91.
So I guess they mixed parts as they transitioned from XA to XB tables.
This table was shipped to Canada as an export on 4/07/76 from Norwood Massachusetts
So I guess they mixed parts as they transitioned from XA to XB tables.
This table was shipped to Canada as an export on 4/07/76 from Norwood Massachusetts
I just saw your thread. It looks like you are on the right track and it will be fun to see your progress. Consider making your plinth a bit taller to allow room the added mass and a piece of foam or other dampening material.
This is how I did it:
https://audiokarma.org/forums/index...ild-with-3009-arm.912313/page-2#post-13801018