The whole idea of a linear tracking arm is that there is no (zero) sideforce (skating force). Vibration should of course be avoided, but if the arm is working right it should not jump grooves. I suggest that you carefully check leveling. (And fix the vibration problem too). |
dr. it hurts when i do this. dr. don't do that.
wall mount. |
A Teres is probably a challenge to wall mount, and my suspicion is that such a mount is not recommended from a sonics perspective for an unsuspended turntable like the Teres. Hence, I'm keen to work on another solution, if one is available. Are others experiencing such an issue (especially with this MG-1 arm)? Note, I am now careful about walking around, and so the cartridge is not jumping, but if I have guests over, I'd like to spin some records and not have to warn them to tip toe around ;-) Thanks!
John. |
If it doesn't happen with your other arm, then there is something with the MG-1 which is different.
Perhaps you have the tracking force set a bit too light?
Perhaps the arm bearing is not quite level?
Air pressure not right?
Check your set up.
Air bearing arms are notorious for difficult set up and maintenance. You might just have to get used to playing around until you get it where you want it.
The more spongy crap you put under it, the worse it is going to be. |
Wall mount. Preferably on an outside wall because they tend to be stiffer than an interior partition wall. Make sure you lag bolt into the studs; if necessary, remove the drywall or plaster and put blocking inside the wall (that's wood that goes horizontally between the studs) and then re-drywall. DO NOT put up a wall shelf with toggle bolts through the drywall or plaster! If you can mount your shelf on a masonry wall, using lag bolts into anchors set in quik-crete, that's the best:~)
For a quick fix before you have time to do the wall shelf thing: Go under your house in the crawl space and determine where the floor joists are. Make sure you position the feet of your rack right over, or close to, each of two joists. (This is assuming the joists run perpendicular to the wall behind your rack.) DO NOT straddle one joist!
If the joists run parallel to the wall behind your rack, the same advise applies but you may have to pull the rack out from the wall to make it work. In both cases, you can "spot-stiffen" your floor by getting some concrete piers at Home Despot (they look like truncated pyramids about 10" high) place them on the ground in the crawl space right under the joists where the rack is located, and using short lengths of 2x4 cut 1/2" longer than the distance from the top of the pier to the bottom of the joist(s) hammer them into place vertically like little columns under each joist where the rack is. This will stiffen the floor at that location and (hopefully) keep your tonearm from bouncing -- which BTW is definitely not good for the cartridge suspension. |
Twl, as always, thanks for the words of wisdom. Yes, I do need to play with it more, and see if I can iron out any remaining kinks. I have tracking set at 2grams which is recommended for the cartridge, but I can up that a little.
Yes, I've been weary of adding anything to the base support. Even as is, I've been weary of using the Adona stand in the context of supporting the Teres, but it looks great, sounds great and has freed up a lot of real estate for me. I've had so many recent system changes on the analog side though, it's difficult for me to attribute gains and issues..I'll keep at it. This MG-1 arm really is interesting, and has been fun to work with - a bit challenging to set up, but that's part of the fun :-)
Thanks,
John. |
Outlier, hope you appreciated my dry wit. If wall mount is not your thing. try this. If your floor bounces you can laod up the mass so the floor is "locked at the bottom of its' bounce" ( a stand made of bricks worked).I mount my turntable in the corner of a room where there is minimal foot traffic. mounting it in the corner gives the floor support on two sides. the closer you are to the middle of the room the more the floor bounces. This is why I beleive in turntables with a suspension. |
Hi Outlier,
When a turntable is placed on a rack situated on a suspended floor there many times will be a tendency for significant mistracking.
When a person steps across one section of the floor that one spot will deflect up and down in response to the pressure of the person's foot. Because the entire floor is flexing in response, the section under the equipment rack is not deflecting directly up and down it will be rocking back and forth. This rocking motion is even more pronounced at the top of an equipment rack. Many tonearms have difficulty in this type of situation and linear trackers are even less tolerant of anything less than a perfectly flat and tranquil environment.
I would suggest that placing a high mass device directly under the turntable will be beneficial in your situation. This will mass load the equipment rack and make it less prone to deflection and rocking. The particular material or device that you choose will be quite critical, however. I would suggest that you avoid materials that ring (such as metal, stone, glass, etc.) as well as materials that are resonant (wood, acrylic, plastic, etc.). Any of these materials will impart its own sonic signature on whatever music the turntable is playing and this will result in increased coloration taking you further away from faithfully reproducing the sound of the instrument as it has been captured in the recording.
We have sold a large number of our Big Rock platforms to people that are in your situation and they have reported very good results. The Big Rock is not only very high mass it is also highly absorptive and has the ability to dissipate unwanted excess energy that is trapped in the turntable's chassis due to air-borne vibration and internally generated vibration from the motor. In addition, it provides a barrier to floor-borne vibration coming up through the equipment rack but it is not a highly compliant device.
Using a highly compliant mounting will not be beneficial in your situation because it may accentuate the rocking motion.
Using a rigid mounting under the turntable will increase the amount unwanted energy that is traveling up through the rack and into the turntable.
Best Regards,
Barry Kohan
Disclaimer: I am a manufacturer of vibration control products. |
Tracking at 2 grams should be plenty heavy for most any cartridge. Given that your pivoted arm seems to not have this problem, i would assume that it has something to do with the way that the air-bearing arm is installed. Then again, the pivoted arm may be experiencing enough side-wall thrust & drag that the friction "holds" the cartridge in place. Otherwise, if the arm / table truly are level in all three planes ( front to back, side to side and diagonally ) and the arm is installed properly, the table simply lacks proper isolation characteristics and / or the rack itself doesn't isn't nearly as good at isolating floor-borne vibrations as advertised.
Given that some of the most fondly loved and reviewed turntables suffer from such a problem, that part of the equation would not surprise me one bit. The fact that the Adona's support the shelves directly under the component also leads me to believe that it would transfer more energy than a rack that supported the shelves from near the edges.
The idea about mass loading the floor in the area near the rack may help somewhat, but you can expect it to change the sonics of the system for the worse too. That is, i think that you'll find that the sound will "dry up" quite noticeably and the bass will become far heavier and less distinct.
Personally, i would suggest going over the arm installation again. Please keep us apprised of what you end up doing to correct the problem as there are many others that are interested in this arm. Sean
>
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a few solutions:
a) don't walk or dance or run during an analogue playback.
b) place an extra pannel under the rack stand. |
Gregadd, suspensions often do not fix the "bouncing" issue, but often make it worse.
My Linn LP12 that I had for years, always had a very noticeable "bouncing" when I walked around the room.(Yes, it was set-up correctly).
My unsuspended table never had any problems like that. |
If you put the table on a Machina Dynamica Promethean Base, not only will you get zero footfalls, the sound will improve dramatically. I can't recommend this device heartily enough for people with unsprung turntables.
http://www.machinadynamica.com/
Oz |
For Gregadd
Mounting turntables in corners opens up a whole 'nother can of worms. Not a very good suggestion IMHO.
Oz |
Hang it from the ceiling on steel wire. It worked when in college, and we had some serious parties!!! No skipping, takes no rack space and it's easy to vacuum under. :) |
My Rega is perched about as high as your TT on a lightweight steel rack with Neuance shelf (suspended hardwood floor). Neuance is rigid and lightweight. I was very surprised how much it helped with heavy footfall/dancing issues. I wasn't expecting that. Might be worth a look. |
I second the "hang from the ceiling" solution. It is equivalent to a light rigid stand for suspended turntable, but is completely impervious to foot falls etc. Also makes it simple to level the platter by adjusting the length of the turnbuckles used on the wires! Loontoon has mentioned the other advantages. |
Guys, thanks for all the input so far. Well, thing is, I'm renting this house right now, so am weary of following any serious DIY type solutions (ceiling mount, or wall mount). I'm also weary of checking out other stands, as I've alreay invested heavily in this one and it really is a beauty (will need to post photos soon - camera is not on hand just now). I guess I could revert to the concrete blocks I once used, and place them in/under the rack (just move one of the rack platforms to the other side of this double rack, and realign) - that might work - could keep all the equipment together (not take up fresh real estate, and maybe eliminate the jumping issue, and the tt would be lower, which is a good thing). Still, I may lose some of the stand benefits I'm getting - if there are such benefits (still not sure just how effective the Adona rack is - but I'm bad at judging such things). Also, the tt looks great perched up there next to my Supratek preamp - both of them showcasing all their wood :-)
Just to metnion, the whole rack is placed upon a brick floor/patio, but I'm not sure where the joists are under all that. Also, I've really no wiggle room to place the rack elsewhere - it really needs to sit just where it is, because I've a projector screen which comes down right next to it - if the rack is an inch away from the side wall, it begins to encroach upon the projector screen
Well, I'll try a few things and keep you posted. Thanks again guys for all the good advice.
|
TWL - yes my sota suspension bounced but the arm and platter all moves as one allowing the record to play without interruption.
Sean- that was not my experience. In fact the sound improved. |
Gregadd: You solved the problem by avoiding the problem. That is, you purchased a real turntable with real engineering behind it. This is not to say that it is a perfect machine, but that it had taken far more steps in the right direction than many of the alternative designs on the market. Both back then and now.
As to weighting down the floor, the results would vary with how much weight was added. I guess that there would be some type of reasonable trade-off between reducing floor-borne vibrations and muddying up the presentation. I ran into this when changing racks and the only weight added was the rack itself. Given that i went from a rack that weighed less than 40 lbs to a rack that weighed in at appr 170 lbs, there was no way for me to experiment or fine tune exactly how much "mass loading" i should use. The end result was that once i got rid of the massive weight of the rack, the sound of the system came back to normal. Sean
> |
Dear John: I'm wonder why you are walking when listening to your audio system.
Anyway, the MG-1 is not an Air Tangent and maybe your problem is a MG-1 problem. I can't be sure.
My advise: meet to a friend of you and test the MG-1 on his system and " see " what happen or try to get ( borrow ) another TT and test on your system.
Now, you have to take all those trouble only if the Mg-1 give you a better quality sound reproduction than your OL Silver.
Regards and enjoy the music.
Raul. |
OZ"curiosity killed the cat" what problems come from mounting a turntable in the corner? IYHO of course.
(from the Wizard of Oz not the cable prison show, right? |
Low frequencies tend to collect in corners. A turntable mounted directly in a corner is subjected to mucho airborne vibrations. Not, as you already know, a good thing for analog playback.
Oz |
You could try putting something designed to "absorb" mechanical energy (convert motion into heat) under the table, such as a Nuance or Symposium shelf. If the floor vibration from walking is a very sharp impulse, but not a very large up and down vertical movement, a shelf might attenuate the impulse enough to prevent the skipping.
Good luck. |
Oz that is true if the turntable is is put in a corner in the direct line of the loudspeakers. I guess it was not clear, I suggested a different room. Mine is located around the corner behind the speakers.I guess that causes problems too. Like long cable runs and makes adjusting vta even more of bitch. I guess that's why this hobby is so much fun. |
Sorry, Gregadd. I didn't catch the part about placing the table in another room. My bad.
Oz |
You would not have the problem were you on a concrete floor. The walls and the ceiling also vibrate. Putting the tt in another room might help as well, if it is more free of vibrations. Putting great mass under it might help as well. A 700 pound curb stone would be unlikely to move easily. I don't like air or magnetic suspensions because of their slow sound, but they might help you. |
Raul: "Anyway, the MG-1 is not an Air Tangent"
What in the world are you talking about here??? Sean
> |
Dear Sean: That's exactly what I'm saying: that the MG-1 has not the quality of an Air Tangent and that the problem maybe is a MG-1 problem. That's all.
Regards and enjoy the music.
Raul. |
sit down when you are listening..ie, don't walk, don't jump up and down...cheapest solution. n'est ce pas? |
Raul: Sorry about that. I misunderstood what you were saying. I thought that you were saying that this is NOT a tangential tracking air bearing arm, not that it wasn't a Air Tangent ( specific make / model of arm ). My bad... Sean
> |
Guys - just so you know - I'm not jumping around the room or walking close to the turntable as I'm listening ;-) However, it is necessary to walk towards the turntable to change records, and walk back to listening position. Also, I do have friends, roommates and guests about now and again, so the issue is not completely in my hands. Hence, that's why I'm still keen to eliminate the issue. I think I can put together a concrete block solution - and will try that. Pity though - as the turntabe is so easily accessable on top of the rack, and looks great. Mmm, still the sound and concerns about cartridge outweigh the aesthetics and convenience factor, for me anyway. I'll keep you posted and will get photos up soon (camera still out of action just now - another story ;-) Thanks for advice on this one.. |
Yikes, mon, you're so keen on your nice TT on top of your sharp-looking rack, and you're going to try a concrete block solution? Whoa, keep your head! ;-> I don't want to push Neuance too hard, but given what you'd like to preserve, you might ask Ken Lyons if he thinks his Neuance would help your situation; he is not hype-ful. Save the concrete for if you really have to get serious. |
Outlier- concrete blocks? Not sure they are heavy enough. You can try it. You can usually scavenge some bricks from leftovers at construction sites. They look better too. If you have space you can add mass to the rack. This is what most people do without even realizng it. You can use bags of lead shot. Cast iron weight plates are also useful. You know the ones weight lifters use on the end of a barbell. Smaller ones can be placed over the tansformers of your equipment to suck up stray magnetic fields. |
I had the footfall problem with a non-suspended table in a livingroom system. Placing the table on a Symposium Ultra Platform which in turn was placed on Navcom pucks on the rack completely eliminated the problem without coloring the sound. |
Your Symposium and Navcom solution should be a quite effective, albeit expensive, solution. Both have different compliances and would be attenuating different frequencies of vibration quite effectively.
I find the use of Symposium platforms, shelves, roller bearings, etc. extremely effective at dissipating unwanted vibrations. Great stuff. |
Outlier, I almost forgot to add one experience I had. I have Mana stands, level 2, under my tt. I was having footfall problems. Lloyd Walker suggested a brace to the wall from well up on the rack. His argument was that the rack does not go up and down as the floor is anchored at the wall; rather it flexs up and down only in the middle but sways the rack fore and aft near the walls. At any rate, the brace worked. This is an effective solution only if it passes WAF, of course. |
John, Make sure the the following steps.
1.Stepping with 3 tip toe under the TT And make sure it will not easy to fall down.
2.Level the TT.
3.Level the tonearm. Adjust the counter weight to balance the cartridge with zero VTF. Then look which direction the arm slide to.Adjust the level cone screw till you get the perfect level.(please keep the cartridge with stylus protect on when you are doing this adjustment).
4.Adjust the tangential (overhang) And give it a approximate VTA now.
5.Adjust the Azimuth.
6.Give the 75% VTF of cartridge's recommend(around 1.5gw).
7.Play some records and make sure everything were well setup already.
There is no fricition between the air bean and slide arm wand when air bearing working. The moving force was gave from the groove of vinyl when turn. Let us think about this. If you do not put the stylus on its right position. what will you get??? Three result.Jump to inside. nothing happan.Jump to outside....
Or If the arm slide without parallel with TT. Yes, 3 result.
Raul, Have you ever been experienced with MG-1?
You are absolutely right. This is not an air tangent.
1.The proto type had been complete on July 2001. The ari tangent announced their 2002 model on Oct 2001. I started to build this arm on Feb 2000 .Did you ever been seen the lathe machine. Yes you are right. The mechnical of MG-1 were base on lathe machine's tool post.
2.Please check the angle of the air beam blow design and level adjust mount design and DRO design between MG-1 and AT's design ( www.airtangent.net http://www.airtangent.net/images/45b.gi ) You will know what I am talking about.
3. I am sorry that I don't even seen the "real" air tangent.
4. I gave the best I have. And share the "real" I have.
If Priced this arm $300.00 USD is a mistake. I think the people will enjoy this mistake as well as I am.
One more thing. I am going to design a TT which will operate by air bearing(experiment complete)with vacuum suck down system. And direct drive mortor....
May I know how much should I ask for to avoid The MG-3 to become to another one well konwn TT's clone...
Thanks for clarify this fact.
Enjoy the music...
Ada |
Loyd is only part right. the tt is moving in two planes both horizontal and vertical. Consider two vectors forming a 90 dgree angle. the resulting vector is 45 dgrees causing the rack to lean. In the case of foot falls as your weight is applied to the floor it sags toward the middle because it is anchored in both the vertcial and horizontal plane. anchoring it to the wall would only eliminate horizontal motion. Unless of course you have created what is essetially a wall mount by making a wall anchor strong enough to restrict the motion in both planes.
No engineers were killed in making this explanation. |
Hi John,
the first thing to bear in mind with any TT/tonearm is that the rig has to be perfectly stable - if it is subject to footfalls then it will be very sensitive to feedback which may not be immediatly obvious, however it will adversly affect your sound. So it's clearly critical to have the TT on a stable platform. If you check out http://www.theanalogdept.com/ you'll see pictures of Teres TT's on wall mounts so if you mount the wall mount properly that will overcome the footfall problem.
Now I dont understand why you should have any difference between the MG-1 and the rega in terms of skipping. DO you have the same down force on each arm? You need a gauge to measure down force - a small digital balance is the easiest to use - it would appear that with the rega you have enough down force to compensate for the instability in the stand, - the downfoce needs to be set for the cartidge - first by the manufacturers specs, and then fine tuned by listening. Dont be twmpted to add downforce to stop it skipping - this will wear out your records and your cartidge and it will not sound at it's best.
Hope this helps
Andy (happy MG-1/Teres 255 user) |
Hi Guys:
Thanks for the extra input. All good thoughts. I'll do a little more experimenting over the weekend and see can I dial in settings, levelling and support a bit more. Also, because this is a double stand (supported on six cones), I may try supporting it on just four cones (eliminating the center ones). I called Adona and received this tip - which sounds like a good one. That should make the effective weight at each of the four supports 50% heavier on average, if my reasoning is correct.
Also, Ada, thanks for the good instructions on optimizing the setup. I believe I have the leveling jsut right, althoguh I haven't applied the methodology you suggest above, which should provide me with better accuracy.
Also, for folks who've suggested adding more mass to the stand, the stand itself weights 230lb, which is pretty beefy in my books as is ;-) The platforms of the rack are granite with some type of substane underneath - looks like some concoction of MDF and tar or something? Anyway, supposed to proved close to flat frequency response.
Anyway, will keep you posted. So many of the above commets are invaluable. Thanks guys. |
http://forum.audiogon.com/cgi-bin/fr.pl?vevol&1007012846
for a corner mount look at this installation by fellow audiogoner BWHITE |
Ever since I broke my leg, I find a wheelchair solves the problem and is cheaper. |
Just updating with a photo of my setup (the subject of all the above advice - thanks again!):
http://cgim.audiogon.com/i/vs/i/f/1112383700.jpg
You can also review my virtual system for more photos.
Thanks,
John. |
Hi Folks:
Just to update, I resolved the skipping issue by moving the turntable to the floor. I think the key problem is/was that the room is one floor up (there's a basement underneath). Hence, the floor is likely not as stable as a typical floor, providing vibration level most folks would not encounter for their setup - a vibration level that no stand can effectively deal with. Also, this tonearm I'm using really must be more sensitive than a typical bearing-based arm, because my OL Silver simply showed no skipping behavior whatsoever. I think the stand would perform admirably in typical circumstances, but my setup is a bit of an 'outlier' ;-) Generally, this stand works perfectly for my other equipment, and if/when I move house I'm confident that the turntable will be back on top of the stand, sounding great and with no skipping behavior. |
I use a Minus K BM-1 isolation platform. This is an industrial product - isolates about 10x better than a Vibraplane (or any other air-based solution), and even outperforms 5-figure industrial active isolation solutions. In fact, the Minus K BM-1 can be used to isolate a SEM (Scanning Electron Microscope) to be used on the second floor of a building. The Minus K BM-1 is also very popular with AFM makers (Atomic Force Microscope). Bottom line: you can go with audiophile/consumer audio solutions which will be inferior while paying a 50% dealer premium, or you can go with an industrial solution which will outperform anything in the consumer audio world and really get your money's worth. Minus K has just released
a new isolator called the BM-6 which has almost the same performance as my BM-1, but at about half the price (under $2k). The new BM-8 to be released mid-Summer goes toe-to-toe with the BM-1 in a much more WAF-friendly form factor. Finally, the Minus K isolators are completely passive, so there are no facilities required for power or air - just plug and play. I'm a mechanical engineer and an audio restoration professional - I know of what I speak. I currently use the Minus K BM-1 with 75 lb granite surface plate under my Simon Yorke S7. Not only will Minus K produce audio nirvana with your turntable, but absolutely no external vibration will reach it. As proof of this, one Minus K user put their AFM on a suspended floor, and had 8 scientists jump on the floor at the same time - there was NO vibration transmitted to the AFM. |
Userid, of course the Vibraplane is made by an industrial isolation company. So is the Halcyonics platform recently shown at the Stereophile show. I guess what is needed is a shootout although I never trust others ears.
I did go to the Minus K BM-1 page. THe BM-6's specifications are not the equal of the BM-1's. I don't know why these companies don't make a rack with this platform at the bottom. If it can be done, it would be more economical. |
I gather that the Minus K BM-1 isolation platform is an electronic device. Long ago I recounted, for audiophiles, my experience with vibration isolation in context of using a large dish of Mercury as a reflector for optical work. Ripples on the surface of the Mercury were a big problem until we bought an electronic vibration isolator. The cost of a SOTA electronic isolator is well within the budget of high end vinyl fans. |
Eldartford, the Minus K is a controlled spring device using no air pressure nor electricity. |
Tbg..OK I found the website which has a good technical description. A very clever device. The picture I found earlier looked very similar to the electronic table that I used. And the price is about the same. The performance is also similar. |
Eldartford, do you have a Halcyonics? |
