Nsgarch and Doug, thanks for both your replies above. Doug, actually it was Nsgarch who suggested the damping trough. He must have forgot too. It was in a previous post I instigated regarding possible upgrades for my SME lV, sometime in December of last year, if my short term memory still works after having just looked it up? "The one upgrade I would recommend, would be the addition of the optional damping trough, if it doesn't already have it." I don't know who mentioned the VTA adjustment that comes with the damper, but it was someone on a prior post, so maybe that was you Doug? Also, thanks to both for clearing up the anti-skate concept. It makes sense now that I have the explanation and look at my headshell. Clear as frozen mud, which would be fun to skate on. :-) As I said, I'll let you know how easily the VTA adjustment works once I install the damper device, and I'll take a look at the SRA link. I may get the damping trough installed this weekend, but I'm working on constructing and installing an antenna tower to mount my Fanfare meter antenna on the roof of the house first. Reception should improve tremendously... I hope. Dave |
Also, call me stupid, but I always figured that anti skating worked in the opposite direction. It seemed, that if I were a stylus, riding in a groove, centrifugal force would tend to spin me towards the outer edge of the record, so I figured anti-skating would counteract this, by exerting some inward counterbalancing force. What you're saying is that the opposite is true. Yes? Since you're smart and brave enough to ask questions you aren't stupid. Ignorance is okay. We're all born with that! ;-) Skating has nothing to do with centrifugal force. In fact, with a properly aligned cartridge there is no centrifugal force. If the stylus is properly tangent to the groove then friction from the groove acts directly along the line of the cantilever. In an ideal setup there is no outward (or inward) force (on the cantilever). Skating force exists only on pivoting tonearms with offset (angled) headshells. Groove/stylus friction pulls directly along the line of the cantilever, but since the cantilever isn't pointed directly at the tonearm pivot a force vector is created. This force pulls the arm inwards and we call it "skating". Anti-skating devices are intended to counteract this inward force by pulling the arm outward, hopefully with an equal amount of pressure. Doug P.S. I doubt I ever recommended the SME IV damping option. I don't own an SME and I've used the V but never the IV. OTOH, if you like it it was *definitely* my idea! |
Dave, excuuuuse me! I completely forgot about the height adjustment screw that's incorporated into the damping trough piece (more likely I "repressed" rather than "forgot" it because it's such a pain in the ass to use!) If you haven't read the long thread I started on determining proper stylus rake angle (SRA, a term more descriptive of reality IMO than VTA) go here: http://forum.audiogon.com/cgi-bin/fr.pl?eanlg&1140840022&openmine&Nsgarch&4&5&st0As for your question about antiskating forces, it is somewhat counterintuitive isn't it!? The INWARD directed force is the result of the tonearm being either "S" shaped, or having the headshell cocked at an angle -- both designs are ways of keeping the the tonearm physically short (9 inches) while minimizing the tangential error of the cartridge alignment to the grooves. (Early tonearms were 12", 16", or even 18" long, straight, with no headshell offset.) However this "offset" design creates a virtual "lever arm" which when pulled on by the friction of the stylus in the groove, tends to twist the arm inward. The easiest way to visualize it is to imagine tying a string to the front of the cartridge and pulling on it. The motion of the tonearm will be in toward the center of the record. If the tonearm post, the armwand, and the headshell were all lined up straight and you pulled on the string, nothing would happen. But with modern tonearms, if you draw an imaginary centerline thru the cartridge front to back extending it backwards, you'll see that the line misses the tonearm post by a couple of inches (to the right). The friction in the record grove multiplied by that two inch virtual lever arm creates an inward twisting force (torque,) which must be counteracted by an equivalent outward twisting force (antiskating force) in the opposite direction. Now, isn't that just as clear as mud !? ;--) . |
Doug,
Thanks for your reply. I have been very carefully placing the stylus onto the lead in spiral. I'll try your suggestion of placing the stylus in one of the first grooves instead.
Also, call me stupid, but I always figured that anti skating worked in the opposite direction. It seemed, that if I were a stylus, riding in a groove, centrifugal force would tend to spin me towards the outer edge of the record, so I figured anti-skating would counteract this, by exerting some inward counterbalancing force. What you're saying is that the opposite is true. Yes?
Nsgarch,
Yes, I purchased the curved horizontal damping trough. It comes with an adjuster for easily raising or lowering the VTA. That's the main reason I spent the money to get it to add to my arm. I find it does make a difference when switching between 200 gm vinyl, and the thinner discs, if I adjust. I haven't bothered much in the past, but the damping trough comes with a little adjuster wand that lets you dial in those minute changes. I haven't installed it yet, but someone (Doug?) mentioned it in another post, and, looking on the SME site confirmed that it provides that function. I'll let you know how easily it works once I install it. It just arrived yesterday.
The Thorens Q-up is an automatic lifting device for convenience, it lifts at the end of the record. I used to have one on my old Thorens table. I actually gave it away when I sold that table, figuring there'd be something more modern and stylish by now to go with my Oracle. Hated the Stylift, and that was all I could find, so I bought a Q-up at hugely inflated prices on Ebay. The Q-up fits between the arm and the platter. Then I bought the Audio Technica Safety Raiser on Ebay too, but I'll use that on my Lenco project table as the Thorens fits so well on the Oracle. I love not having to jump up, or even listen to the stylus at the end of the record riding in the lead out spiral.
Thanks agin,
Dave |
ALWAYS drop the stylus into the first groove and not into the lead-in spiral -- for all the reasons Doug says. Yes it requires eyesight (glasses?) and a little practice -- but any decent engineer has cut a few seconds of silence into the first track, so you won't miss anything once you get the hang of it.
Rolloff, maybe I misunderstood. Did you add the curved horizontal damping trough? -- the one that comes standard on the SME V, or are you talking about something else? (I don't understand how it helps with VTA for instance.)
Also the SME IV comes with a damped cueing lever, so why would you need the Thorens Q up -- or is it an automatic device for convenience? |
Good info here from Neal and Doug. I have found that some of my lp's just defy cuing without falling into the groove with a bit of a jolt.
Just me or do you guys have a few of these records as well? |
I have had problems with the stylus skating in from the lean in spiral, even though, I seem to have all my adjustments properly set up... Dave, This is normal for any properly set up arm with high quality bearings, which your IV certainly has. Four factors combine to cause this behavior: 1. the stylus is more likely to touch down onto bare vinyl than hit the groove, so there are no sidewalls to resist lateral movement; 2. the instant the stylus contacts spinning vinyl, skating forces try to pull the arm inward 3. most LP's have an inward sloping lead-in ramp, so gravity is reinforcing the inward tendency; 4. high quality bearings present little resistance to arm movement (arms with rough, tight or sticky bearings have enough friction to mask this situation, which is why people moving to a top level arm from cheaper ones are often surprised or think they've misadjusted something). There is no adjustment you can reasonably make to counteract this. Increasing antiskate to very high levels would prevent it, but that would be far too much antiskate for proper performance once the stylus finds the groove. The "cure" is to cue slowly, carefully and purposefully. Don't just flip the cueing lever and walk away. Maintain control of the arm during cueing and listen for the stylus to find the groove. Once it does it's safe to release or push the cueing lever all the way down. This is especially tricky on edge-warped records BTW. Practice on flat ones first. Doug |
Nsgarch,,
As always, thank you for sharing your valuable knowledge. I got the damper, mainly as it give me the ability to more easily adjust the VTA. I'll look at the article you posted. Interestingly, I use a Thorens Q up for lifting the arm at the end of the lead out spiral, and have never noticed a problem there. I have had problems with the stylus skating in from the lean in spiral, even though, I seem to have all my adjustments properly set up...
Thanks,
Dave |
Rolloff, the internal wiring of the SME IV is a metallized ribbon, not wire. Supposedly, this presents less resistance to the bearings, and is also supposedly more compatible with MC cartridges -- for which this arm was specifically designed. So you wouldn't want to change it IMO. The arm itself is not that old , maybe 5-8 years? You can find out but it is much newer than an SME V, and unless "you don't know where it's been" it shouldn't need routine service. As for the damping tray, I can't tell you if you really need it or not because I can't find any info on the compliance of the Shelter 90X. (You probably don't.) Most MC cartridges have low(ish) compliance and are appropriately used in med to high mass arms (like the SME IV.) So the arm doesn't need to be damped as far as resonances are concerned, though it can help to keep the arm from overshooting the lead-out spiral, but that shouldn't happen if the table is level and the arm limit properly set. Now if you were to use a high compliance cartridge (like a van den Hul, or many of the MM or MI cartridges) in a med/high mass arm, you might find the damping helps. Here is a quick overview of the issue: http://www.gcaudio.com/resources/howtos/tonearmcartridge.html. |
Nsgarch,
I've got an SME series lV arm (on an Oracle MK V table) that I just purchased a fluid damper for. I don't really know how old the arm is? How should I go about determining if I should send it back to SME for service and new wiring? Any suggestions are appreciated.
Thanks
Rolloff |
Thanks for the responses. I was planning on mating it with one of the Denon MC cartridges for now, possibly a 301. I will be jumping from a SME 3009 +linn Adikt. I guess you might say it is a big jump, but I don't see an reason to make lots of little jumps in between.
Regarding the vdh wiring, is there a big difference between the 150s 150m and 300 M? Which do they use? I read somewhere that the rewire with non standard wire made a significant difference.
It appears somewhat popular to knock the V, but given that it was designed with suspension in mind, it is probably the best choice. Could someone please explain what in particular makes it a better match, other than it is not a uni-pivot. Is there anything else I should look at?
Lastly, if I buy used, do the Vs bearings suffer with age? I presume the tightness of the bearings are critical to the success of the tonearm.
Thanks again |
I'd agree with the Raul and Nsgarch. The SME would be the better choice. I don't think the unipivot on a suspended table is necessarily bad, Basis has been doing it well for years. If you want a uni, I'd suggest saving up some more and getting the Phantom or a Basis Vector. MY .02.
Best,
Dan |
Raul is correct about the internal wire being better on the new SME V. HOWEVER, if you buy an older one, and send it back to the factory for service (which you should do anyway) SME can install an even BETTER van den Hul wire than what they put in their current production arms.
That's what I did with my 16 y.o. arm.
I don't like suspended tables, mostly because I think they're a pain in the ass to use, but a unipivot on a suspended table -- I don't think so ;--)
. |
Dear Quadtriumph: The only change over the years on the V was the internal wire. The V is the " natural " couple for your Oracle.
The RB1000 is a very good tonearm but the V is more versatile.
Which your cartridge?
Regards and enjoy the music.
Raul. |
Sorry, there are a bunch of unrelated questions here. I am on the verge of pulling the trigger on a new tonearm for an Oracle tt, which is a suspension tt. I have heard both a Graham 2.2 and a SME V,( but not back to back), on the same rig, and both times I was impressed. What I am trying to figure out, is what is a good match for a suspension tt. From what I understand, traditionally, it has been the SME style.
As I am probably buying second hand, I was trying to figure out a few things:
1. Whether there is any difference between an upgraded 1.5 (to a 2.2) or one that was bought as a 2.2).
2. The SME V has been around for approx. twenty years, and I was wondering if there have been subtle changes over the time. Is a 1985 SME V the same as a 2006 SME V?
3. Lastly, there does not seem to be much discussion about the Rega RB 1000. Is this arm just not in the same category?
Thanks |
Yes, the difference between Graham 1.5 and a full 2.2 is HUGE but it will depend on the quality of your Phono Stage. |
