Can a stock AR-XA suspension handle a 16 oz brass weight?

[beatcomber]

Quick question -

I've recently put my 100% stock AR-XA back into my main system and am wondering if the suspension can be adjusted enough to support a 16 oz brass record weight, or are the springs just not strong enough?

Right now, it's tuned perfectly for use without a weight, and so I wanted to check in here before I go messing around with it. A quick Google image search pulled up zero images of AR-XAs with weights (excepting heavily modded tables), which makes me suspect that it's not a good idea to use one with this table.

 

[Dr Tinear]

Have you considered using a clamp instead of a heavy weight? I used the Revolver PIG clamp with my AR XA. It cleaned up the sound without bottoming the suspension or even requiring any adjustment to the spring mounts. The PIG is sadly out of production, but KAB has a 2-ounce clamp that would probably work even better due to its larger contact area with the label.

I suspect that the XA's stock springs don't have enough adjustment range to keep from bottoming with a 16-ounce weight, though I never actually tried this combination when I was running an XA in my system.

 

[beatcomber]

Have you considered using a clamp instead of a heavy weight? I used the Revolver PIG clamp with my AR XA. It cleaned up the sound without bottoming the suspension or even requiring any adjustment to the spring mounts. The PIG is sadly out of production, but KAB has a 2-ounce clamp that would probably work even better due to its larger contact area with the label.

I suspect that the XA's stock springs don't have enough adjustment range to keep from bottoming with a 16-ounce weight, though I never actually tried this combination when I was running an XA in my system.

Thanks! I had considered that I might need to get a clamp instead of a weight, but since I already have the weight, I figured I'd start there.

 

[majick47]

Beatcomber I have about a half dozen clamps/weights and I'v done a fair amount of reading on the subject. My feeling is that if the mfg included a clamp/weight in the design of the turntable it will be able to accomodate it. If you use another one of close to the same weight as the original you should be fine. Clamps that are reasonably light weight shouldn't be a problem either. It boils down to is there anything gained by useing a clamp/weight when the turntable mfg didn't recommend or provide one. Much like turntable platter mats the weights/clamps for the most part are eye candy at a marked up price like fancy cables that gave the dealer/mfg a very healthy profit margin and did little or nothing to improve the sound and in some cases was/is detremental to the performance/life span of the turntable.

 

[beatcomber]

It boils down to is there anything gained by useing a clamp/weight when the turntable mfg didn't recommend or provide one. Much like turntable platter mats the weights/clamps for the most part are eye candy at a marked up price like fancy cables that gave the dealer/mfg a very healthy profit margin and did little or nothing to improve the sound and in some cases was/is detremental to the performance/life span of the turntable.

Well, one has to consider that record weights and clamps didn't even EXIST when the AR-XA was designed!
Can anyone comment on the relative benefits or drawbacks to using a clamp with the AR-XA? Perhaps it performs better without one.

I have a center-drilled hockey puck that I used to use with my SL-1200... I think I'll try opening the hole a tiny bit more (it's too tight for the slightly larger AR-XA spindle) and see what improvement, if any, there is.

 

[Dr Tinear]

I found it worthwhile to use a clamp with my AR XA, and I still use it with my Technics belt-drive turntable. Consider that a record sitting on a mat can vibrate in response to acoustical energy from the room, much like a large microphone diaphragm. This energy then gets picked up by the stylus and amplified along with the desired signal from the grooves. Clamping the record in place makes it less able to vibrate in response to sounds in the room. The results I heard were cleaner sound and a lower noise floor. The improvement was enough to convince me that an inexpensive clamp (the Revolver PIG was less than $10, if memory serves) was a useful accessory rather than a piece of audiophile eye candy.

 

[beatcomber]

I found it worthwhile to use a clamp with my AR XA, and I still use it with my Technics belt-drive turntable. Consider that a record sitting on a mat can vibrate in response to acoustical energy from the room, much like a large microphone diaphragm. This energy then gets picked up by the stylus and amplified along with the desired signal from the grooves. Clamping the record in place makes it less able to vibrate in response to sounds in the room. The results I heard were cleaner sound and a lower noise floor. The improvement was enough to convince me that an inexpensive clamp (the Revolver PIG was less than $10, if memory serves) was a useful accessory rather than a piece of audiophile eye candy.

That has been my experience as well with the brass weight. On some tables the improvement is more pronounced than on others though.

 

[Dadbar]

I use a clamp with mine and it works fine. If you have the stock springs you will bottom out the outer platter with a heavy weight unless you buy stiffer springs for it- there is only a few mm of play between the outer ring and the deck. I have a set of the Scilla stiffer springs that I've not used on mine yet because they require a deeper plinth than the one I have and I just haven't gotten around to doing that.

 

[beatcomber]

I use a clamp with mine and it works fine. If you have the stock springs you will bottom out the outer platter with a heavy weight unless you buy stiffer springs for it- there is only a few mm of play between the outer ring and the deck. I have a set of the Scilla stiffer springs that I've not used on mine yet because they require a deeper plinth than the one I have and I just haven't gotten around to doing that.

What a classy-looking set you have there! Vintage yet still modern. :tresbon:
Which arm is that?

 

[marcmorin]

I use a clamp with mine and it works fine. If you have the stock springs you will bottom out the outer platter with a heavy weight unless you buy stiffer springs for it- there is only a few mm of play between the outer ring and the deck. I have a set of the Scilla stiffer springs that I've not used on mine yet because they require a deeper plinth than the one I have and I just haven't gotten around to doing that.

If the springs are preloaded to 70%-80% of static height, the plinth height is fine. The problem with going to heavier springs on the AR tables is there is not enough mass in the platter/T-bar to get the springs to proper load thus they appear too long. A set of Linn Black springs requires an additional 3-3.5 pounds of mass added to the T-bar to get all three spring loaded equally and to proper compression. Anything less than 80% compression height (vs stock un-loaded height) and the spring will not filter down to its 2.5hz it is supposed to. 80% compression will have fuller bass (loose suspension) 70% compression will tone down the bass in favor of midrange (tight suspension)

Back to the original question posted. No, your suspension will not support a center weight. Even if you can still adjust your suspension to it, you will overload two of the springs and blow the tuning of the table out the window.
If you believe the album is somehow vibrating and needs clamped, try going with a deer hide mat first.

Marc

 

[beatcomber]

Thanks, Marc! I was hoping you'd chime in.

 

[marcmorin]

Thanks, Marc! I was hoping you'd chime in.

Hi, if you need photos of suspension tuning, and what i'm refering to...here's my email

BaMorin@AOL.com

Marc

 

[beatcomber]

Much appreciated, thank you!

Right now I have it set at about 1/8" off the surface of the plinth, per the owner's manual.

 

[bhundu]

FWIW I use a 205g aluminium weight on my Thorens tables. Tuned for the extra weight, they work fine. 16oz seems to be about 445g which could be a bit too heavy in my thinking.

 

[beatcomber]

Makes logical sense, bhundu. Thanks, I may look for something like that.

I gotta say, I am VERY impressed with the stock AR-XA. I hadn't given it a good listen in a long time, but I think it's gonna stay in the 'good' system. I put a Shure V15 Type 4 with JICO SAS stylus on it, and it sounds fantastic. Previously I had used it with an M91ED and that was terrific too. Imaging is excellent, and music sounds very alive. Excellent PRAT, very 'bouncy' (and I don't mean the suspension!), detailed and musical.

Bass is a slight bit softer than I like, but I think that can be remedied by a better choice of mat. Right now I'm using a felt DJ slipmat from an Audio Technica AT-PL120, but will try out a DIY cork mat shortly and see how I like it.

I tried out the hocky puck clamp last night and didn't notice any real improvement, plus it was a PITA to get on and off the spindle.

 

[marcmorin]

Makes logical sense, bhundu. Thanks, I may look for something like that.

I gotta say, I am VERY impressed with the stock AR-XA. I hadn't given it a good listen in a long time, but I think it's gonna stay in the 'good' system. I put a Shure V15 Type 4 with JICO SAS stylus on it, and it sounds fantastic. Previously I had used it with an M91ED and that was terrific too. Imaging is excellent, and music sounds very alive. Excellent PRAT, very 'bouncy' (and I don't mean the suspension!), detailed and musical.

Bass is a slight bit softer than I like, but I think that can be remedied by a better choice of mat. Right now I'm using a felt DJ slipmat from an Audio Technica AT-PL120, but will try out a DIY cork mat shortly and see how I like it.

I tried out the hocky puck clamp last night and didn't notice any real improvement, plus it was a PITA to get on and off the spindle.

Hi, the cork mat should work better than the slipmat. Soft kid leather, or deer hide would work even better yet.......as has been my experience. To tighten the bass up, a little more slam and more definition of the bass note, a more massive pulley, a change in the lower spring grommets, and work on the arm pivots/pivot boss, change the arm post thrust bearing. To really blacken the background and gain even more speed stability, polish the spindle and ball end, change the thrust bearing. That takes about 20 minutes of time.

 

[beatcomber]

Thanks, Marc.

Everything's working properly, ie: the unit runs smoothly and quietly, so I'm off to a good start. But before I start down the long scary road of upgrades and mods, I first want to do the basic servicing (ie: cleaning, polishing and re-oiling the spindle and tonearm bearing and wells, cleaning/polishing the pulley, etc.).

work on the arm pivots/pivot boss, change the arm post thrust bearing. To really blacken the background and gain even more speed stability, polish the spindle and ball end, change the thrust bearing.

I'm not sure what the above means exactly. (I'm not very mechanically savvy, but I'm willing to learn something new.) Where would I get a replacement arm post thrust bearing? Is it a standard size available from a hardware store?

Do you recommend damping the metal T-bar with, say, rope caulk?

 

[marcmorin]

Thanks, Marc.

Everything's working properly, ie: the unit runs smoothly and quietly, so I'm off to a good start. But before I start down the long scary road of upgrades and mods, I first want to do the basic servicing (ie: cleaning, polishing and re-oiling the spindle and tonearm bearing and wells, cleaning/polishing the pulley, etc.).



I'm not sure what the above means exactly. (I'm not very mechanically savvy, but I'm willing to learn something new.) Where would I get a replacement arm post thrust bearing? Is it a standard size available from a hardware store?

Do you recommend damping the metal T-bar with, say, rope caulk?

Adding goo to the T-bar only upsets the balance that AR designed into the system. Any noise in the T-bar, being metal, travels in a longitudinal manner.
the goo doesn't do anything. The "noise" in the T-bar comes from sub-platter spindle rumble. Polishing that, and adding a thrust plate at the bottom of the well greatly reduces rumble.......as well as reducing friction (friction turns into heat and noise)

The same goes for the tonearm bearing well. The ball at the bottom of the arm spindle is riding on a delrin thrust plate that has a wear dent in it. You don't have a single rotation point, that is now a "ball and socket". Adding a steel thrust plate over the existing thrust plate will reduce lateral arm drag to 50mg or less friction. The thrust plates are simply "drop in"

regarding the arm vertical pivot assembly..........the steel collar that the brass barrel sits in has to be fused into a single piece. Right now yours has play between the brass and steel collar. I'm sure you disabled the pin in the brass barrel so there is no reason that the barrel should need to move independant of the steel collar. Removing that extra area of arm wabble really cleans the music up.

shoot me an e-mail and I'll send pics on how to polish the spindle properly and what the thrust bearings look like.

Marc

 

[beatcomber]

Adding goo to the T-bar only upsets the balance that AR designed into the system. Any noise in the T-bar, being metal, travels in a longitudinal manner.

Makes sense. The AR-XA is so well-engineered (except for the plastic headshell ) that I suppose that everything is done for a very good reason.

The same goes for the tonearm bearing well. The ball at the bottom of the arm spindle is riding on a delrin thrust plate that has a wear dent in it. You don't have a single rotation point, that is now a "ball and socket". Adding a steel thrust plate over the existing thrust plate will reduce lateral arm drag to 50mg or less friction. The thrust plates are simply "drop in"

Where does one get a replacement thrust plate, or can I just make a round steel plate and drop it in? (My wife is a metalsmith, so she can probably fabricate one for me.)

regarding the arm vertical pivot assembly..........the steel collar that the brass barrel sits in has to be fused into a single piece. Right now yours has play between the brass and steel collar. I'm sure you disabled the pin in the brass barrel so there is no reason that the barrel should need to move independant of the steel collar. Removing that extra area of arm wabble really cleans the music up.

????

I need to study the arm assembly to understand this.

shoot me an e-mail and I'll send pics on how to polish the spindle properly and what the thrust bearings look like.

Marc

Excellent, will do! Many thanks for your assistance!