EMF Measurements
Using an EMF Field Tester, range 0.1 - 200m Gauss I found the following measurements interesting.
Highest EMF emissions from vacuum tube preamplifier.
2" above the power supply 23m Gauss
2" above the tube circuitry 8m Gauss
15" to the side of the preamp 0.1m Gauss
15" above the preamp 3-4m Gauss.
The conclusion is that it may be better from an EMF view to place the equipment beside the TT and not underneath it.
As regards to the magnetism tests, on my Final Audio Parthenon, which uses Copper mat, Aluminium platter, gunmetal & SPZ bearing housings and base, there is no magnetism measured at all - none.
Halcro, could it be that you enjoy the Victor more because of its magnetic personality ? Magnetism in ferrous metals can be masked through the use of chrome plating. Some of the Japanese high end tube manufacturers use this technique of a chrome plated and painted steel chassis because the common alternative, aluminium, induces hysteresis distortion in the electrical signal when aluminium is placed near an electrical flow.
I have seen the Technics SP02 DD motor in a cutting lathe situation; the motor was mounted about 2 1/2 ft below the cutting head and the platter was 50kg. This is probably the way you should build a DD. The alternative would be to convert your DD to a thread drive and mount it all in a non magnetic chassis.
Final suggestion for the Victor owners who want to dispense with the flimsy cover, why not build a faraday shield but mount it to the shelf, not the TT. This will provide shielding and minimise resonance. |
I guess Syntax might say that he is not surprised that you prefer the TT101 to the Raven for deepest bass response. I've never yet owned a BD tt with a platter that would meet Dertonearm's standard for mass, so I have no opinion (and in fairness, I may be misquoting the minimum mass, but the parameter "35 lbs" sticks in my mind). I did at the time take some issue with his explanation for the finding, which was not solely based on rotational inertia. |
|
Halcro, To reiterate, copper does not shield against magnetism, electro- or other, largely because, as you noted yourself, copper is non-magnetic. Also, electrical insulators that you list are not good insulators against magnetism. Stainless steel can be magnetized because it has a (low) iron content. Alu will be as good as rubber, i.e., not good. Distance from the source and ferrous materials are two ways to reduce the magnetic field.
Chris, I think you answered your own question re the Dynavector, if I understand you correctly. It seems there was no detectable contribution from the magnet at the rear of the DV pivot when your detector was at the headshell. Thus, I would think, there is nothing to worry about (based on the fact that you read the same value of 40-ish when the tonearm is not in the picture). Moreover, the DV magnet is actually two magnets held in place in apposition over the stabilizer blade that is fixed to the moving part of the tonearm. Most of the magnetic lines of force would stay localized to that area because of the interaction between the two apposed stationary magnets and the moving blade that is already deliberately created. Yes, I think DV knew what they were doing, as they have stuck with this basic design for nearly 30 years.
Same goes for the Verdier: it uses two huge magnets of opposite polarity to elevate the platter. The magnetic lines of force are therefore concentrated in that space between the two giant magnets. Stick your detector down there, and see what that does. Also, the thick platter gives distance from any possible problem up on the platter surface. |
Which leads me to ask myself. Dynavector is a well respected company. if they thought there was a problem with magnetism would they have built their tonearm to be joined with their cartridges ? Good question Chris. One would think not? |
I tried that droid application for magnetism.
curiosity got the better of me. Some "fun" observations.
I set the magnetism scale to the highest level so the bar would not peak.
Holding my phone in my left hand I took hold of a fridge magnet with my right hand.
I have a boatload of these now leftover from my ET2 magnetic damping experiments.
Sure enough as I brought the magnet closer it would register on the proximity graph.
Sort of like in the movies where they show crew in submarines with radar. As I came in closer the levels would go up.
So it does work - but how accurate is it ?
The sp10mkII first.
While holding it about an inch above the platter away from the cartridge it showed numbers in the 40's.
Turning the power supply on caused the number to jump to the 80's. Now the interesting part.
Pushing start reduced the number to the 40's again.
Lenco. unfortunately this test was ???? as the big magnet laden Dynavector tonearm sits on this table.
It started in the 40's and as I brought my phone toward the mid section of the Dynavector the scale would want to shoot way off.
Which leads me to ask myself. Dynavector is a well respected company. if they thought there was a problem with magnetism would they have built their tonearm to be joined with their cartridges ?
Verdier - the most surprising since it uses two very large magnets (shielded) for levitation. With my phone just above the big platter. The lowest levels observed in the teens and 20's.
Cheers |
Thuchan,
Don't get me wrong.......
The Raven AC-2 is an excellent turntable providing very stable speed control and superb analogue performance when set up correctly.
It has audibly kept level with the TT-101 until this last 'nudie' change I have made.
And in my 35 years experience listening to all the best turntables I could access.....the TT-101 is simply the best.
The fact that I have extracted a performance level from the Raven that is so close......speaks volumes I think?
I will not be selling the Raven :-) |
To be fair to Dertonarm Lew.....he was referring to belt-drive turntables with his 35 lbs platter comment.
His logic.....and that of many other belt-drive designers.....is that greater mass creates sufficient inertia in the revolving platter to overcome stylus drag?
He also advocates non-elastic string or thread drive instead of rubber which means that the platter is not insulated from the cogging of the drive motor.
This of course requires a superb motor design.
For a direct drive turntable with a quartz-locked servo motor.....particularly a positive and negative servo control like the TT-101......the lightest possible platter will make speed changes less perceptible than a heavy one.
A common mistake that critics seem to make when discussing quartz-locked servo control....is that the servo is always 'hunting' for the correct speed?
They disregard the notion that the speed is quartz-LOCKED. The speed is generally spot on and not 'hunting' at all. The only time speed correction may be applied is under localised untoward stylus drag when....as you correctly remark.....good torque and bi-lateral speed control come into their own. |
You're right Thuchan,
There appears to be 10 times more Cu-180 platter mats available for sale.....even NOS ones.....than Micro ever made in their day?
Similar story with the Orsonic headshells....:-)
Aren't the Chinese great? |
Lawrence,
It was magnetism......not RFI/EMI that surprised me on the Cu-180 turntable mat?
The Micro Cu-180 is indeed non-magnetic.
My ignorance levels on electro-magnetism run deep.......but I'm guessing that there are materials which can act as 'conductors' whilst others are 'insulators'?
That's why the stainless steel of the 'cradle' I designed became 'magnetised' by the strong magnetic field and why the non-magnetic aluminium platter of the Victor becomes 'magnetised'.....or at least allows the magnetic field to pass through?
The same effect must be in operation with the Micro copper platter even though it is 3mm thick?
I can understand the rubber platter mat being an 'insulator'.......but a 1mm piece of pigskin being a sufficient insulator bowls me over.....
And why a 2mm thick piece of vinyl is NOT an insulator.....I don't know?
I'm sure someone will educate me?
Where's Al when you really need him?? :-) |
Halcro,
there might be only one conclusion, get rid of the Raven :-)
isn't it time for a change? I don't know about the value of these modern machines right now. I always went for technology, musicality and a rare design when going for tables. My tables kept the value, they instead increased. I really don't get it why some audio friends pay horrendous amounts for everyday tables which basically copy an originial, to the better? |
I just went to the URL provided by Aigenga. The photos show exactly what I did, as well, to create an EMI shield for my L07D. However, I never heard any "wum-wum" when the brake activated, either before or after shielding was installed. That site is the one hosted by Howard Stearn, who is an orthopedist by day and an L07D Lover by night. |
Halcro, I would not expect copper per se to do much to absorb or block a magnetic field, except by virtue of its thickness which would just physically space the LP and the cartridge that much further away from the source. I am glad to hear your report on the comparison between the TT101 and the Raven. There are many in the audio community who say otherwise, and I never could figure out a scientific basis for their claim, that you need a very massy platter to have good bass reproduction. It seems to me that a combination of torque and well done speed control would be as good. If you will recall, Dertonearm once wrote here that at minimum, a platter MUST weigh 35 lbs for good bass.
Lharasim. Are you certain that copper is not an effective EMI shield? TI Shield, which is a documented effective EMI shield, is composed of three layers: copper/permalloy/copper. True, it does not work unless the copper surface is grounded. Perhaps it is the permalloy layer that does the work. I don't actually know. |
Halcro copper will do nothing with EMI on for RFI
Lawrence |
Halcro,
there came out so many Micro Seiki CU180 metal plates out of China in the last years MS couldn't have produced in the golden (!) times of Japanese turntable building... |
I can't vouch for the app but the phone has a compass in it which has to be a magnetism detector. So if the app tells me that there is a concentration of magnetic field in certain places and if it is consistent in that reading across multiple tests under varying circumstances then I must believe that it is so. Likely the absolute measurements are not to engineering standards but I am not using the numbers only the relative magnitude of the readings at various spots around the TT.
I don't know if the strength of the field rises to a problematic level - might be cartridge dependent. I also don't know how a problem would present: noise?, loss of detail or dynamics due to magnetic interference? Maybe I'll be able to fix the situation and maybe I will hear a change. I'm skeptical that I will. Gary |
FWIW, "Gauss" are a unit of magnetism. EMI is measured either in Volts per meter or Watts per meter-squared. |
Does a tt need a massive heavy platter to reproduce extreme low bass? This seems to be an interim conclusion by respected reviewers like Michael Fremer and Jonathan Valin but they obviously havent heard the TT-101? The Victor can go deeper than the Raven AC-2 (depending on cartridge in use)
but more importantly
the bass can sound more natural, better controlled with less overhang and more definition. Perhaps the physics is different with belt-drive decks
.but the short answer to Lewms question is
.not in my experience. :-) |
Well
I read the interesting article on RFI/EMI linked by Banquo. Whilst it deals specifically with the Kenwood L-07D turntable
.I dont doubt that its observations would also apply to most unshielded DD turntables? Whilst the writer begins criticising the L-07D
The tonal range is also reduced. The sound stage is compressed. Stereo separation is reduced
.and there is a roll-off of the upper registers
I hear none of these artifacts with the TT-101 compared to the Raven AC-2 and the Continuum Caliburn. In fact
these are some of the areas in which the TT-101 playback excels
compared to other turntables? I also hear no wum wum wum sounds through the speakers when the brake function is activated. My experiences with RFI/EMI problems are that if they are present
..they are audible. Simply place the stylus on the vinyl and turn up the volume way past that at which you normally listen. A hum or drone emanates from the speakers which increases as the volume increases. With my TT-101
.I can turn up the volume to maximum without any extraneous noise whatsoever. I am more concerned at the possible unknown effects of the wayward magnetism inherent in those DD turntables? So I decided to do some tests on the actual strength of this magnetism. Using my trusty vertical magnet tester
I placed it on the bare aluminium Victor platter and felt its pull. Was it enough to hold the magnet whilst the platter spun? Yes it was! I then decided to try it with the Micro Seiki Cu-180 solid copper platter mat in place. I was surprised to find the magnetic field was not deterred one iota by the copper platter and the little magnet stayed upright. Methinks the Cu-180 is a fake gunmetal copy painted gold? :-( Could this magnetic field extend through the copper/gunmetal AND a vinyl record?
..is the Pope catholic? Next I tried to emulate these tests with the original Victor rubber platter mat and then the Victor 1mm pigskin mat directly on the aluminium platter and could not get the little yellow magnet to even stay on the surface
.let alone stand at attention :-) |
Aigenga, looks be just a iphone app. I have a droid OS, was thinking if others do try it would be best to use same software. Have to say I would be skeptical of accuracy of an app for this application. The one I tried was finicky. |
Sounds like I was wrong in assuming the app measure EMI and not magnetic field strength, as "Gauss" is a unit of magnetism (but it might also be a unit of measure for EMI; I need to check). I have no evidence that magnetics is any problem with L07D or SP10 Mk3, the latter of which has a humongous magnet and a very powerful motor. Anything ferrous will block or absorb magnetic forces. When you did your measurements, was the TT101 fully assembled and running? Did you compare with and without the "pants"? Possibly blocking magnetic field from the transformer or motor is the primary or a secondary function of the pants, since we do know they are ferrous. ("Old Ironpants.")
The discussion of the awesome Final Audio tts and their relatives brings to mind another audio conundrum. Does a tt need a massive heavy platter to reproduce extreme low bass? Halcro may have an opinion on this, since he is running his TT101, which has one of the lightest platters I have seen on a TOTL DD tt, vs the Raven tt, which has a typical massive platter associated with the high end belt-drive tts. Henry, do you perceive a difference in bass reproduction between the Raven and the TT101? If so, in favor of which tt? Thanks. |
I am using "Teslameter 11th" from skypaw on an iPhone.
Gary |
|
Aigenga, what's the exact name of the app you are using? |
The app measures micro tesla or mili gauss - both seem to be measures of magnetic fields. If I said that I know much more than that I would be lying.
I don't yet know if I will cover the motor area - leaving ventilation space or make the mu metal sheets part of my mat, one way or the other.
Gary |
What does the app actually detect, EMI or "magnetic fields"? Those are two different phenomena. I would expect it detects EMI. I don't think this is endemic to every single DD turntable ever made; I would expect it is something to think about on a case by case basis with any particular DD. However, as Banquo mentioned, the L07D cognoscenti recommend implementing a shield between its motor and the platter. It seems to me that Kenwood already did that: the platter "mat" is actually a 5-lb piece of quarter-inch-thick stainless steel, which while not being a perfectly efficient shield, does act as a shield. Nevertheless, I did buy a piece of TI Shield from M Percy. I cut it in the shape of an LP and tucked it in under the stainless steel platter mat, so it does not show. I then was able to imagine that it made an improvement; I don't trust such uncontrolled observations when made by the guy who did the work and spent the money (me), but there you have it. One could do the same or similar for the TT101 or any other DD. A copper platter mat would do some good as an alternative. The SP10 Mk3 has a massive piece of bronze or brass in its surface, which probably affords some shielding. Unfortunately, last time I looked on M Percy's website, there is a notation to the effect that TI Shield is No Longer Available. I don't know whether that means it is out of production or only no longer sold by Percy. He does also sell ERS cloth, which could be made to do the job.
Note that any shield must be grounded to be fully effective. I am assuming that, since the TI Shield on my L07D is fully in contact with both the base platter and the SS mat, and since they are in continuity with the bearing, my shield is grounded. (TI Shield has layers of copper on both sides; it is quite conductive. Be careful.) |
according to this, it is a problem, Aigenga. I believe Lewm investigated these issues with his Kenwood. Sorry I don't have a smart phone but next time friends come over I'll have them do it. The symptoms of rfi and emi contamination that site articulates are certainly troubling. I don't detect them in my set up, but I suppose along each of the dimensions things could be better--so who knows. As I noted above, I stuck some pieces of TI Shield underneath my subplatter right above the motor cover. Perhaps that is doing me some good? And if I used a heavy platter mat I would use the shield directly beneath it--but the boston audio mat 2 wasn't heavy enough to flatten the piece I cut. I think the mu metal is thinner. |
Is no one interested in the magnetic fields concentrated at the normal arc of the cartridge? It would be helpful and interesting if someone with a smartphone would install the Tesla app and repeat my experiment.
Is this a problem? Does it effect all DD turntables?
I have ordered mu-metal sheets to try and redirect the magnetism away from this area. More on that in a week or so.
Gary |
Dover,
Thanks for the info. I tried Googling but there is sparse detail available.
That Final motor looks serious........ |
Halcro, 09-12-13: Halcro
And here is the equally famous Takai Lab Final VTT-1 belt-drive turntable similar to Dover's.....although he has the Parthenon model I seem to recall which is quite different to this one? The Final in the picture is missing most of the TT. It is a VTT1 Platter & bearing with non standard Lead Console plinth, and a Pioneer DC motor drive. It is missing the original SPZ plinth and it is also missing the original sine & cosine wave regenerated power supply and original motor. Here's an early Final VTT1 with the SPZ plinth. http://www.hifido.co.jp/KWfinal/G0301/E/0-10/C09-43580-46106-00/In my VTT1 the wine/cosine generator is separate from the motor and uses a separate power amplifier for providing motor drive. The Takai/Final Labs preceded both the Melcos and the big micro's by 7-8 years. The Melco's are interesting - they use embedded titanium in the bearing assembly, and the thrust pad is mounted on a spring designed specifically to the platter mass. The platter uses the Okubo mass formula to obtain equilibrium and minimise bearing "friction". The Takai/Final Labs have an inverted bearing, placing the platter centre of gravity well below the bearing point, whereas the Melcos/Micro use the conventional bearing. The Takai/Final Labs also use sine/cosine wave generated power supplies for the AC motors. The Melco's & Micro's are less sophisticated in this area. |
Banquo363, you beat me to it. BTW thanks for the report of trying your table without the tin can. |
Very informative. Thanks again. |
The problem I see with the post connection is if anyone has fooled with them in the past the leverage from the post will have a tendency to move the eyelet on the other side if done without caution. I would unwrap then rewrap with less turns and resolder eyelet on backside and solder the wire.
If you translate that link you would see the ones with solder are suppose to be the repair.
|
There were no bad parts, just bad connections. I ended up resoldering all the feed thru eyelets, then flipping the board and removing the solder with a sucker, then resoldering them with much less solder. They all look pretty clean now. I know other companies that used the eyelet method had reliability problems. For some reason the solder cracks around the eyelets, probably related to different coefficients of thermal expansion. That's from an email my tech Dave Brown sent me. In a different email, he distinguishes between what he calls 'feed thru eyelet' boards and 'plated thru' ones. The Victor evidently uses the former. I am completely ignorant of the meanings of the 2 terms--am just passing on others' wisdom as I received it. |
Yes those post are soldered on the other side and are used in that fashions so as not to have to remove the pcb to service other conecting components.
To me this is a prime example of a reason to service the bearing of the motor, nothing last forever as much as the manufacture would have you believe.
|
Ecir and Banquo, Before reading Ecir's post, I was about to say that I looked up the definition of "feed through eyelet" via Google, and to my amazement I found the definition. I had never heard that term before. Ecir, in one of those URLs I do see a number of short posts with wires wound or obviously soldered to them, on the various PCBs. There sure are several of those in the TT101. I will check them. But the formal definition of a "feed through eyelet" is a connector that goes through a PCB, connecting a circuit on one side to a circuit on the back side of the same PCB. Guess I will look for those too. (Or perhaps those posts do connect to tracings on the other side of those PCBs, which would not be visible in the photos.) Thanks to you both. |
Lew, I think what Banquo is talking about is that wires that go from one board to the other are fastened by wire that is just wrapped around a stud that is soldered to pcb. This is a known problem and should be addressed if it hasn't been already.
See pic here for description notably at tranny's a/c connections. If you look closely the same procedure is used throughout. Now these pics are from a TT71 and not sure if the 81 and 101 are similiar.
http://amp8.web.fc2.com/amp-etc/record/victor/tt-71-2.htm
http://www.amp8.com/amp-etc/record/victor/tt-71.htm
|
Banquo, Your idea of the cause of the glitches in my TT101 operation is a good one. When we first got it to run at all, it exhibited all sorts of crazy forms of malfunction, even though every single electrolytic capacitor had been replaced, and Bill eventually tracked it down to bad solder joints or solder tracings, just as you say. He told me he spent a lot of time re-soldering various tracings (for which he did not charge), and his work resulted in what appeared to be complete success, based on how the table worked in his shop. It is quite possible that the mechanical trauma associated with travel from his place to mine (about 20 miles on the DC Beltway, which is not exactly cushion-y) put some stresses on other tracings that are now faulty. Can you be more explicit about what you mean when you say "feed through" tracings? I was thinking that soldering of the wires in one or more of the many multi-prong plugs that interconnect the various PCBs could be the source of the current problem.
Halcro, Of course you have every right to post on the subject of this thread (heh-heh). I personally have no desire to argue further about plinth, no-plinth, or arm pods. This is not because I don't care but rather because I can see now that your rig is very nicely done so as to mitigate any criticism I might have of the concepts. I still think that the basic structure of the L07D, with the rock solid connection between the bearing housing and the tonearm mount, is ideal, whether or not the L07D is top dog in all other ways. And as I've said several times, I do also think that getting rid of the "deck" structure surrounding the platter is beneficial. The more the tt chassis resembles a cylinder with the diameter only slightly greater than that of the platter, the better. This is one way toward good sound, not the only way. Fortunately for us, it is easy to achieve the latter goal with the Victor and Denon DD turntables. |
OK, now I am confused and a bit concerned. I used the Tesla meter to measure stray magnetic fields (as the device tells me) and lo and behold the only area that had high readings was at the top of the platter mostly on the right side of the table. Right where the cartridge tracks the record!
I repeated the measurements with the table grounded and not grounded, with my lead mat on and off, with the platter spinning and stopped, with the power on and off.
I even tried it on a TT-81 that hasn't spun in a year and got similar results! Is this a problem for DD turntables?
There is something in the TT itself that emits a notable magnetic field - I would guess it is the motor. I don't know how to address this but I certainly think that the magnetic operation of the cartridge is affected by this and not in a good way.
I would really like to hear that someone else has repeated this experiment and what they found.
Time to investigate Mu metal and how I can fashion a shield.
Gary |
Lewm: My table basically went through all the symptoms you describe and then some. My tech reasoned through and tried testing many of the complex explanations. But in the end, we discovered that it was all attributable to bad solder joints on the 'feed thru eyelets'. He resoldered ALL of them. He said he knew of companies that used such type of boards and that they had reliability problems. Since you're handy with a solder gun, I'd try this brute method first before potentially wasting time investigating the subtler possibilities.
Aigenga: No worries. The thing is, I did note the number of turns and even marked the spot but when I put it back together the platter was completely locked up. Obviously, I screwed up somewhere--but I believe I know how to count, so it's still unclear to me what happened. I have zero plans on doing that again for the next 30 years.
Halcro: I don't have a general problem reproducing bass, but the double basses on that Mahler record, while better after the pantsing, sound far from adequate. I blame my speakers or the lack of subwoofers. Or, for all I know, it's the record itself. I just purchased another better copy of that record so I can test the last possibility soon.
fwiw, I don't have anything invested in the new set up except 15 minutes of time (2 to take the cover off and the rest to realign the tonearm and cartridge). The improvement is remarkable. It's along the same trajectory as the improvements I noted when I moved from my sp10 to the victor. |
Perhaps a thong. But then one's other turntables would be attracted.
I hope Halcro does not mind this diverting of his thread topic from nude to TT101 nude, but I have a TT101 question for other users: Even after Bill Thalmann blessed mine, I still have the following occasional problem. The TT will start up and go to 33.32. Then after 5-10 seconds, it goes to 33.33. After about a minute or two more, it will go to 33.34. Very shortly thereafter it will shut itself down. The tachometer reading disappears, and the brake effect does not occur. The platter spins freely until it loses momentum. If I manually press the STOP button BEFORE the unpremeditated shutdown, there IS a correct brake effect. I had been thinking that there is a problem with the reverse servo mechanism to explain this, but you guys have me thinking that there may be some inordinate drag on the platter, meaning my bearing may need service. On the other hand, if that were so, I would expect to hear a frictional sound (the table is dead silent) and I would not expect the platter to spin so freely and silently after shutdown. Comments?
I am embarrassed to tell Bill about this glitch, because it worked perfectly in his shop when I picked it up. But of course I will tell him eventually. He is a kind and patient man, moreso than I. |
Your TT may have to be confiscated siting indecent enclosure Heh heh.... OK you twisted my arm.... An even more indecent shot......and another |
And here is the equally famous Takai Lab Final VTT-1 belt-drive turntable similar to Dover's.....although he has the Parthenon model I seem to recall which is quite different to this one? I particularly love the 'Copernican' ideal of the separation of platter and arm-pods.....and this execution appears to be particularly elegant. Again Dover and Lewm should be well pleased with the 'plinth' arrangement selected here? :-) |
Your TT may have to be confiscated siting indecent enclosure :) |
Now here's a Belt-Drive from the famous Melco brand. The legendary Melco was a High-End Japanese turntable manufacturer equal to Micro Seiki with cost-no-object products in the 1970s. This model I particularly like because of the strong skeletal steel backbone 'plinth' which should satisfy Lewm and Dover completely :-) |
Lewm, Why re-open the argument? Errr.....because that is the subject of this Thread? :-) Incidentally......have you managed to listen to your TT-101 yet? |
Dover,
I have a stethoscope and have done all the listening you suggest...and more, and hear nothing "revelatory" in regard to 'noise' within my turntable structures.
However this is by no means a scientific or 'white paper approved' form of documentary evidence which laboratory testing could easily provide?
Your use of terms like "noise", "friction" and "vibration" are inexact, undocumented and unquantified.
Hardly a convincing argument regardless of how often you continue to repeat it? |
I am delighted to hear Banquo confirm my listening impressions. I am well aware of the audiophiles need to hear improvements with any change. Especially a change invested with a personal attachment? :-) One other difference to note is that everything seems quieter. I don't mean the noise floor has dropped, but rather that I seem to want to turn the volume up nowadays. This is what I meant by the term purer
and turn the volume up is exactly what I do also
Incidentally
.I spoke too early about the fix to the speed read-out. Yesterday it went to 33.32 rpm on start-up before hitting 33.33 rpm
Im intrigued Banquo about your bass problems? Are these a function of your speakers, room or amplification? Surely not a source issue? |
Lewm, I think the belts are a good idea but insufficient. You need the suspenders as well on those pants. By that I mean the sound dampening sheets.
On my iPhone I have an app called a Tesla meter which measures stray electrical currents (RFI). I got this to measure what was coming through my TT's can. The results told me that the transformer puts out a notable amount. I don't recall what the situation was with the ground wire at the time as I have used it in multiple configs. As I recall, the tranny faced the tonearm - food for thought. Clearly I should do some clean experiments and have good data to report - in a day or two I should be able to get to it.
Banquo, I feel guilty enticing you down the path of changing the oil and subsequently getting bearing-level problems. I experienced the same and that is why I emphasized returning the screw to the exact position in my last write-up. But of course that was too late a warning. Sorry.
Gary |
08-27-12: Dover
Victor 101 -
Could you get rid of the flimsy bottom cover completely and mount the nude deck via an inverted tripod ? It doesn't look particularly rigid from the photos.
Potentially could you remove the internal transformer and some of the electronic boards from the main chassis and mount them separately to eliminate as much vibration as possible. Make sure all internal joints are as rigid as possible. It is pleasing to see my suggestion in August last year to remove the flimsy bottom cover being successfully trialled at last. Thanks to all who have tried it. 09-10-13: Halcro
Despite the availability of accelerometers and other devices designed to measure and quantify vibrational energy and its transfer within materials
..I have seen no scientific evidence to support the many statements made by audiophiles on the nature of vibration draining in regards to turntables
.and any quantification of such? You appear to be saying that the "improvements" you claim your new TT support structure are merely a figment of your imagination since you state "I have seen no scientific evidence to support the many statements made by audiophiles on the nature of vibration draining in regards to turntables" My view is that there are several sources of unwamted noise and vibration in TT's. That is one of the reasons that TT manufacturers publish noise floor specifications in the form of xxdB. When playing a vinyl record, the stylus generates noise and vibration as well as the music you hear, resulting in vinyl record wear and stylus wear. Most turntables have a platter that uses a spindle and thrust bearing to provide the ability to rotate. When the platter bearing rotates, this generates noise. Worn bearings are a direct consequence of this friction. Both of these phenomena are a source of vibration and noise. In order to "see" it, I would suggest you purchase a stethoscope and have a listen to your turntable, whilst it is working. Then have another listen when it is not working. This simple experiment may be revelatory for you. |
