Interesting Chris....as I have also found the 420STR to act much like a LOMC on my Victor DD in its susceptibility to 'feedback' when the volume is turned up?
This despite the fact that the phono stage gain is set to the low MM value which, incidentally displays no such 'feedback' with 'normal' MMs?
Do you have any thoughts on why this should be the case with the 420STR? From the nude thread Perhaps the fact that the 420STR is like a giant antenna (according to Chris and the Professor Timeltel). Hi Henry – I gave this some more thought. I prefer to label the 420str as a “Nude” cartridge – I thought u would like this name? The 420str has very little “clothing” so why not call it nude. Its not damped and protected to the nine’s like other cartridges so it needs an arm that can pass thru or eliminate resonances really well. If you have any issues with your turntable setup, it will tell you like no other cartridge so far for me. This can be good or bad depending on your perspective. On a belt or thread drive TT where there is excellent motor isolation, this cartridge has had no issues for me whatsoever. It did however require me to lock things down better on the idler and dd tables, thus its value to me for more than just the sound, but as a test cartridge. I believe that most of the favorable impressions of the 420str here, were with belt / thread drive users ? Is this not so ? I look forward to your impressions of it Henry - on your Belt drive Raven when u get your phono stage up and running. As an update the 420str arrived safely and is with BT. Slaw – I found a Shawn Colvin - Steady On - LP. :^) |
Hi Dover – thx for the info. Please tell me there is not going to be a pop test quiz on that material.
More on resonances
My Verdier plinth – which holds the platter, armpod, spindle (no physical bearing) instead two large shielded magnets - is made of Granito.
Granito is a material composed by little pieces of marble of very different origin agglomerated inside a mold with cement. Machined and polished.
The resonance of the plinth with its suspension is about 5Hz and it is well absorbed by the air cavities.
The Granito and resonance info comes from Mr.Verdier himself to me in an email.
My SP10 unit (version 4) is bolted in by four - one inch solid stainless columns to an MDF plinth which in turn sits on a pneumatic suspension, which in turn is on a wall shelf (load bearing) The MDF base is a full TT system plinth as it holds all the goods. It supposedly resonates a little lower than slate. The armpod 19 lbs relies on its weight alone but my version 5 plans are to have it bolted in as well, and I am not sure what material the next plinth will be.
The Nantais L75 is an all wood layered plinth and I have convinced myself that if I take my boat to the middle of Lake Ontario and drop it over it will sink. It feels like cement when carried.
This has been said before – The ET2.5 spindle resonates at 2-3 Hz. The skinnier ET 2.0 spindle resonates at around 5-6 hz.
Resonances can be fun ? |
Slaw
I liked the pic you provided us of the wire Take Five Audio built for you. I loved the attention that was paid to the gradual step down coming out of the WBTs. Was this accomplished with teflon tubing? Slaw - I just got Gene's answer I am quoting. "For those WBT RCA's the buildup was done with several layers of shrinktube. The first piece is 1/16" CPX 100 Black, you have to be EXTREMELY careful when applying heat so that you do not fuse the insulation together on the wires. From there it is built up using 1/4" and 3/8" CPA type shrinktube with the last piece covering the first two for an overall clean stepped appearance." here's the pic again - I am not affiliated with Take Five - Just a customer. http://cgim.audiogon.com/i/vs/i/f/1332259084.jpg |
Slaw - the most enjoyment I have ever had out of this hobby as an pure amateur "having fun hobbyist" is when I personally do something (DIY) to my setup that improves the sound. Reading your posts it sounds like you are really enjoying yourself. Pics for everyone ? |
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Hi Slaw -
Bruce got a second 420str that was "donated" to me.
I have been enjoying my Acutex 420 all this time and want to thank Frogman and yourself for the Donald Fagen and Shawn Colvin recommendations. Those LP's are in regular rotation with me.
Bruce has been very busy and has been travelling but I was in touch with him last week. He is really glad we sent him the cartridge and he made the time to listen to it. He is in fact sending me a short review of it which I will post here.
I didn't want to say anything till I received the review.
More later.....Armpod huh ? .....
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Everytime I've put on either of my copies of "The Nightfly", I took it off before the 1st song was through! This was for the purpose of listening to (enjoy), and I still couldn't get past it. Slaw - Frogman was clear in telling us that it was a digital LP but he also used some words if you go back to the post like slick or polished sounding. I agree with this. Imo - Vinyl is a very tweakable and variable medium. How we tweak our room/gear to play vinyl is based on many factors, each us are a little different, and this influences what we do with the gear in our own room/s. Even if we had exact same gear, our rooms are all different. For me personally the first time I played a master tape copy against the LP version (same pre/amp/speakers/room) my personal vinyl preferences became very obvious to me. They were exposed so to speak. There is no hiding behind a pretty sounding cartridge with tape. It forced me to deal with the room/gear and try to bring it to an acceptable level for myself. I have also had a few members of my daughters high school jazz ensemble in my room a few times over the last 4 years to play for me – just for a few minutes. Each time this revealed flaws in my room. The room is the most important factor, and it will never be perfect. My room is ok for my reproduced sound as I have control over it to a degree. Not for live music. imo - There is no reason you should not be able to enjoy Nightfly. My recommendation is to play more LPs’ like Nightfly and adjust your gear/room to where it is tolerable enough and you can at least enjoy the music. Isn't that what this is about. Once you have done this I believe the other good analog sounding lps like the Shawn Colvin one will sound even better. The 420str doesn’t sound pretty, its been said here before. Its also doesn’t cover up. So this is playing a factor too in your room. On the ET2 I find the 420str very honest in its presentation and I find the tone good compared to my tapes. Just some thoughts ... Hoping to get Bruce’s review of it this week. |
I found his comments about his preference for the ET2 with this cart to be interesting; I wish he had elaborated on the reasons why. Frogman - when you contact Bruce maybe he can confirm this. This information is from Bruce from his testing - it was posted earlier in the thread somewhere near the beginning. The ET 2.0 smaller diameter spindle resonates at 5-6 hz. This applies to regular and high pressure 2.0 models. The ET 2.5 which only came as a higher pressure model has a larger diameter spindle resonating at 2-3 hz. If I have a choice I usually run MC on my 2.5 and MM on the 2.0 but both work well with either. The higher compliance MM's (imo - resonating higher) just seem to work better to my ears on the ET 2.0. Less tweaking involved in setup. So I agree with what Bruce said. With that I have the 420str on my 2.5 right now and it sounds great. |
Something wasn't made clear in the my last post. Once installed the damping trough function is easily engaged and dis-engaged by just turning the paddle screw knob which raises and lowers it. The tip from Bruce was the paddle just touching the fluid not slugging its way through.
Cheers |
I used to know a guy that had owned his ET2 for over 15 years. During this time he had 2 wives. During the marital turnovers he managed to keep his ET2, but did give up some other prized gear. IMO – if this ET2 tonearm had lots of shiny metals on it that looked like gold and silver, he may not have been so lucky to hang onto his ET2 this long. It’s a sleeper.
Its already been said here that the ET2 has stood up to the hardest test of all – time. Anyone can buy a 20 year old ET2 tonearm on the used market and make it work. Even if replacement parts are needed they are available at reasonable cost. |
Hi Mark Wow - thats a great price on these pumps. Here is a direct link to your site. Medo PumpI paid $60 or something like that for each of the two I had. Placing a really small fan next to the pump will alleviate any worries of overheating. Years ago I accidentally left mine on all weekend to return with no problems. Cheers Chris |
Antiskating and Frequency Modulation Distortion of Different Tonearm Geometric Hi Guys (gals?) There has been a few different threads on the Gon recently about turntables maintaining their speed - Speed Stability. The effect of stylus drag with turntable speed is always mentioned and acknowledged. I continue to go back to Bruce Thigpens ET2 tonearm manual, and find information that I had either overlooked or forgotten about. IMO - for anyone in this hobby this manual contains important data. Here is BT's information on this subject, the forces involved and some real measurements. The Et2 manual on page 51 says that an LP record contains approximately 40% vertical energy and 60% lateral energy. These are significant and different forces at play. BT did testing of these forces as they applied to different tonearms. The manual section that summarizes these findings follows. Taken from “the Eminent Technology ET2 Tonearm Manual - Pages 46 and 47”. Disclaimer - This is public information and is available online at the Eminent Technology website under support/manuals/ET2 owners manual. Antiskating and Frequency Modulation Distortion of Different Tonearm Geometric
Pivoted tonearms are designed so that the head shell holds the cartridge at an “offset angle” with respect to an imaginary line drawn through the tonearm pivot to the stylus tip. The arc traced by the stylus tip extends past the record center and is defined as “overhang”.
This design approach minimizes tracking error. There have been many articles written about the geometry of this design approach. Pivoted arms create several side effects which reduce phono cartridge performance. The first is a skating force which results from two different parts of pivoted arm design.
There is a force component (vector) that is directed toward the center of the record. It results from the stylus drag force vector not falling in line with the pivot point of the arm. This force pulls the tonearm inward and the stylus can be observed as bending outward. This force and the resulting bending can be demonstrated by connecting a rubber band to a pivoted arm around the cartridge body and pulling it straight (away) from the tonearm. Note: the motion of the tonearm is inward and results in bending of the rubber band (cantilever).
If you corrected these forces with an anti-skating mechanism such that the stylus did not bend (you can not really do this because the frictional force and resultant bending varies with groove modulation, stylus shape, tracking force, etc...) there still exists another component of skating.
This second skating force results because of overhang. There are frictional force vectors that result which are not directly ahead of the stylus. The surface of the record is not really moving straight ahead with respect to the stylus tip. As a result, there are force components directed ahead and toward the center of the record. The magnitude of the inward force depends upon the degree of overhang.
This means that any given cartridge works against lower horizontal forces in the Model Two tonearm (.1 gram or less) compared to a conventional arm (.2 grams/gram vtf). These figures apply if you use records that are not severely out of round. If you like to play severely eccentric records, ones with runout of greater than 1/8”, then we suggest you use a low mass pivoted arm.
For vertical forces while tracking warps, the cartridge suspension system must work against the tonearms moment of inertia about its vertical axis of rotation. For the Model Two, these forces will be similar to those of a conventional tonearm which has low to medium effective mass (10 grams). Fwiw - As an owner of both pivot and straight line tonearms I am aware that stylus drag differences differ with each. I never did take any measurements. It is now possible with software, a test disc and your Android or Iphone to measure things like turntable speeds and tonearm resonances, as discussed in this thread. See the post from Halcro |
Hi Mark – that is excellent news. Was there any difficulty connecting your cartridge leads to the 420str ? The back of the cartridge is angled up - a tight fit with the ET2 armtube if longer leads are used? ...suggestions from others certainly appreciated!. Only thing I would offer up right now is to leave things as they are for a few days to establish a reference point. Then remove as much lead weight as you can to get the weights sitting past 6 on the I Beam scale. Your bass will become ...... well why don’t we let you tell us what it does for you ....... . Some previous hints are in previous pages here on the thread. I like to think of the I Beam as a Pirate Plank. Get out as far as you can on that plank without falling into the water. My I Beam with the 420 str has the base lead weight plus only one thin lead weight on it. Its past 6 on the left side and I can just see the very edge of the I Beam on the right side. Looking forward to hearing about your progress... Cheers Chris |
Hi Dover – I have an offer for you. As the current holder of our famous “420str Celebrity”, I am willing to send it to you next, to the other side of the world - with only these conditions. 1) You are able to resurrect your unique ET2 2) Provide us with your impressions here 3) Promise to send it back to me within three months of receiving it; So that it can be prepared for the next recipient. You see Dover, the way I see it; I am not worthy to just hold onto this crackerjack box cartridge. A cartridge that looks just like it fell out of a model airplane package. Especially with talks of $10 – 15k cartridges on the MM thread, this cartridge which demands nothing more than perfect tracing, needs to be experienced by as many as possible. I figure what better way than sending it to New Zealand. Lets call it our threads version of the blue or red pill. Do you think you are ready for the Red Pill? Offer stands..... |
If you have long lead clips, forget it! Now sounds very linear, with some added emphasis in treble Exactly what I found Mark. The added emphasis with me decreased with break in. But again it was very linear meaning it was noticeable over a period of time not overnight. A general question to all. Can a cartridge with known emphasis in treble, if placed at an offset in the groove, cause this “emphasis in treble” to sound like harshness, sibilance, distortion ? |
Offset – Just to be clear in my previous post when I say offset - I mean anything that is not a perfect zenith IMO as an end user – since vinyl records are not perfect (both in their physical attributes and the way the masters were cut) – no tonearm out there is able to come to a perfect zenith. Anyone disagree with this ? Some however 1) allow you to come closer to Zenith in setup, and 2) keep it there during play. In this hobby I personally want a tonearm that can do both 1 and 2. Fwiw - I have had two 420’s on two ET2’s simultaneously. I was able to tell by listening which one IMO came closer. This forced me to fine tune one of them. |
Richard - I don’t pretend to understand the math. I will ask Bruce again when I can for clarification.
Dover - Lets face it – the manual contains great information but is in a really bad need of a re-write with some pretty fonts that audiophiles will actually like to read. A summary two pager to get up and running is also needed to hit the top 10 points. |
Hi Mark – from the specs in the manual which shows all three the 415 is closest to the 420. I have the 412 not the 415. I found it wasn't as linear as the 420 (hf, mid, lf). Frogman is using a 412 to make a new body for his 420 ? Maybe he will chime in if he sees this. I recommend a quick post on the MM thread asking for a 420 and for someone to pm you. Pretty sure somebody will respond to you. I paid around 70 euros for the 412 from what I recall. Cheers Chris |
Slaw - Mark asked for an opinion - I gave one. I am done with cartridges myself. Unfortunately I keep misplacing/losing the damn screws in the carpet. I hear tinkle tinkle sometimes when I vacuum. Hence my post about the screws. Have a nice day. I have to go shovel snow. Haven't seen anything like this in 10 years.
Cheers Chris |
Hi John47 :^) - raising fraternal twins can be entertaining too. My wife and I are into our 18th year of dealing with their demands in “stereo”. This hobby and a little sense of humor has helped me through it to this point. The twins have shaped my humor however – made it more cynical I think. My wife doesn’t care too much for it. She also doesn’t care for music above 70 db. Probably explains why I am here.
Rugyboogie - welcome to the thread. Am curious if you or other Kuzma Airline owners have ever considered any modifications to that tonearm?
Cheers |
The pump talk reminded me that Ketchup provided ET2 flow rates to us back in Nov - here is the link to his post which contains the information from his testing. Thx again Ketchup. ET2 Flow Rates |
Richard Krebs ET2 Setup (Custom) Richard Krebs ET2 setup pic 1Richard Krebs ET2 setup pic 2Hi Richard, if you are in a position to discuss many are probably wondering what I am right now from looking at these pictures. I have to ask if any of what we see can be duplicated, made again, or was it a one time effort of passion ? Not your typical counterweight setup ? If you are not in a position to discuss – understand - wonderful setup. Cheers Chris |
Hi Richard – thanks for joining the thread and Ketchup thanks for that link which shows better pictures. Richard - A lot to think about in your post thanks for sharing. I need to digest it some more. A few things that hit me immediately though. Big jumps in performance were the goose neck. This was made from the same grade of aluminum as the wand. The bracket that joins the wand to the spindle. I have always wondered about that Gooseneck – listed as the joint in the ET2 arm parts list. Before I ask Bruce if he can make a special run of aluminum ones for Et2 owners , do you have a source for making them ? If we asked ET2 owners here we could probably come up with a certain number of owners that would want to try an aluminum one? I know I would take two for the different size ET2 and ET 2.5 spindles. The manifold and arm pillar are made from acrylic. Lead is inserted and epoxy glued inside these to sink energy. VTA is adjusted by a removable screw after loosening 4x M5 cap screws. Manifold and pillar are locked solid once these are tightened.
Arm pillar is fused to the plinth effectively making it one assembly. I really like your custom arm as it is sleek and clean looking but that the adjustments have been eliminated that could cause movement. Very solid but you can still make VTA adjustments. Chris you have a regulator, water separator. It looks like it uses brass fittings and appears to be close to the arm. Try soldering a wire to the exit fitting and earthing this. I don't know why this works but it is possibly something to do with static electricity build up in the air stream.
On the topic of static electricity try rubbing the wand with AFC anti static foam cleanser. The stuff they use on photocopier glass. I am definitely going to try both of these ideas - thanks Have removed the Teflon in the head shell and replaced with a square of 1/2 mm thick lead and superglued in place. Others have tried different materials here also with good results. I have not got around to doing this. I remember Dover discussed doing this on his ET2 as well. Its a bit of a pain to remove that Teflon piece ? I have a new arm on the drawing board based on what I have learnt from this one. Richard - Will this custom arm be designed for a specific type of armboard / plinth, or will it be designed to be used with different armboards/surfaces ? Your counterweight is now fixed. I assume you are are not using the leaf spring? We have discussed the advantages of the single, double triple spring here. This would be a very interesting discussion plus the lead slug you mention. Cheers Chris |
Ketchup
Anyway, can you believe that I can not find one photo of a Garrard 301 with an ET-2 or ET-2.5 arm? Ketchup - Does a JN Lenco with an ET 2.5 count ? |
Richardkrebs
With a pivoted arm the horizontal effective mass in multiplied by the head shell offset. Only a percentage of the cantilevers lateral movement is resisted by the arms horizontal mass in trying to rotate the arm the rest of this movement is resisted by the cantilevers efforts trying to bend the arm tube itself. Linear arms do not impose the second characteristic on the cantilever. This I believe is one reason that the pivoted arm guys complain about a lack of gestalt from linear arms. We largely fix that with oil troughs or magnets. Pure mass is another option Hi Richard – Have you actually measured these forces? I find it very interesting that what you say is supported by information I have from BT on actual testing that he has done with pivot and linear arms. His measurements found that this phenomena (horizontal effective mass, multiplied by the head shell offset and the resulting bending of the cantilever) produced a +6 to 12dB bump between 10-15 Hz versus flat response down to 5Hz (the ET-2). He also went on to say that “over the years these parameters have been mathematically analyzed and are well understood. There is an easy measurement to prove all of the above, it is called is wow and flutter. If you take the same turntable, put a straight line tonearm arm on it and a pivoted tonearm, both with the same cartridge, the straight line arm will exhibit about half the measured wow and flutter.” I have his summary findings on this if anyone is interested. Alot of his findings again are in his ET2 manual available publicly. Some of it was posted here already here already. Richard, Dover others ...... any comments on this very basic wow and flutter test ? |
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Hi Richard – email sent.
Where are my manners ? Do you want to try the 420str cartridge?
Your table and arm would need to be set up for the higher compliance.
I was all ready to send it to NZ anyway.
When you are done you can maybe pass it to Dover? I think Dover misplaced his ET2 - and I think it may have something to do with a drink called Slivovitz from Serbia. Maybe Nandric (Nikola) can provide more details on this.
Hopefully Dover gets it back soon
Glad you guys on the other end of the world have a sense of humor.
Cheers Chris |
Dgarretson
Dover, can you clarify a few points concerning the effective horizontal mass of ET? The manual states that it is 25-35gms. Is this the mass of the wand plus manifold tube, which is then increased by addition of up to 40gms in counterweights? Hi Dave Page 5 of manual – spindle weight (14 grams) tonearm tube weight (11 gms) plus the counterweights. To give you a reference point I am using one large and one small counterweight with the 420 str. That should be 20 gms. Page 9 ‘By decoupling the counterweights horizontally but not vertically, the mass of the counterweight is not seen by the cartridge above a certain frequency and is lowered. This allows use of heavier (more rigid) components in tonearm design with increasing effective mass. Decoupling mechanism is damped at a 2 – 5hz.” Maybe Dover, Richard or others can add more regarding the horizontal inertia. "lots of variables" YUP :^) Cheers |
Dover - if I may say - you come across as a real hard ass sometimes in your posts; but you have a very direct sense of humor. lmfao.
btw - what I just said my kids say to me alot. they unfortunately both being only 18 have not yet seen alot of my humor. I try to save it for you guys as I my wife just doesn't appreciate it either. This thread is 11 pages long now. She will never be able to trace back to what i am saying here.
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Richard, My ET 2.0 versus the ET 2.5 – both have high pressure manifolds. First an observation as I read what Ketchup and yourself said about the compliance in the air bearing spindle. Ketchup do you notice any difference in force required to move the spindle in your ET 2.0 and ET 2.5 with no air on? My ET 2.0 spindle can be forced through the manifold with no air. There is quite a bit of resistance but it can be done. This is normal according to Bruce. And its anodized coating prevents any damage. My ET 2.5 spindle will not move – it is really tight. There is not much movement at all without air. It has to be really forced. Bruce built it a few years ago for me. It was designed to run at 19 psi. Unlike my ET 2.0 which will run at 19psi and a low 3 psi as well, my ET 2.5 will start binding up if I drop the pressure – not sure what the actual PSI number is. The spindle starts resonating above a certain psi. We have discussed this here before. The consensus seems to be this PSI number varies just like our individual setups. For me its 19 psi and the reason I had the arm made for that psi. Richard as far as sonic differences with me. Let me use an analogy. We have all seen those graphs that show motor oil and the difference between lets say 5w30 and 10w30 motor oil at different temperatures. http://i36.photobucket.com/albums/e29/2002neonrt/35graph.jpgLets assume lower temperature represents lower compliance / heavier cartridges – that is the ET 2.5 5w30 and the ET 2.0 is 10w30. Both overlap and work well within a large range for both MM and MC. But when the setup is tweaked/improved I think the ET 2.0 works a tad better with MM and ET 2.5 with MC. Does that analogy make any sense? People assume the ET 2.5 is better because it is (.5) the next newer version. It depends. It came after so the obviously the parts themselves are newer but as far as sonics go ? well we know the smaller diameter 2.0 spindle according to Bruce resonates at 5-6 hz. The 2.5 resonates at 2-3 hz. The armtubes are the same as far as I know for both versions. Aluminum original one better with higher compliance, CF – middle ground – Magnesium – for really low compliance. This is the advice from Bruce with the testing he has done. The ET 2.5 sucks more air – has more volume. When they were in the same room I remember how the pressure gauge when I unplugged one for other would move by a few PSI. Ketchup’s graph shows this too. The ET 2.0 was around when vinyl was in its heyday along with MM cartridges. Then came MC cartridges and BT adjusted (I guess) to the time and introduced the 2.5 with its lower resonance. Just an opinion. If all things were the same – apples to apples - We know that will never happen. The ET 2.0 seems to handle a little better with lighter higher compliance MM’s. Like a lighter sportscar with great handling. But add a bigger motor to the sportscar (heavier MC/stiffer/lower compliance ) and I feel the ET 2.5 handles a little better. Bigger diameter spindle along with the lower resonance. A very rigid spindle to manifold coupling in my 2.5. The differences are not day and night. The MM 420str sounds great on the 2.5. Its just seems to be a little more ease on the 2.0. Bruce’s review of the 420str kind of confirmed this to me too. So I use MC on my 2.5 and MM on the 2.0. The rooms are adjacent to one another in the basement. Hope that helps. Richard you mentioned that you studied the Dynavector arm. Did you take any measurements of it - Impressions ? Cheers |
Richardkrebs
Chris
I initially used one fridge magnet then went to multiple fridge mags. Finally using Neodymium before abandoning the idea.
I tried first at the counterweight end then transferred to the wand end. There are differences. Now the reasons for that could be a whole new controversial discussion.
Richard - We are all big boys here and we all know this hobby has a lot of controversy as it is based on preferences. Please do share the differences you found. |
A real interesting read for me the last couple of days. Ketchup please keep us updated on those shims and I hope you get "one" of your arms up and running soon. Yes I was referring to the compliance between the “spindle and manifold” only. Sarcher30, John47 welcome to the thread. Excellent video link Ketchup. The ET2 tonearm no magnetic parts to be found anywhere on the tonearm itself. Put a magnet to it and find out for yourself. The cartridge itself, well don’t put a magnet there.....how close is ok or is it ? It got me curious. I hate unknowns. I have been reading both Richard and Dover’s positions on it. Have learned alot. I have something to share regarding these magnets, magnetism and it has to do with my Dynavector tonearm. I took one of the small circle magnets from the ET2.5 setup over to my Dynavector tonearm. What followed kind of reminded me of one of those horror movies –you know the one where the guy wakes up and finds himself magnetized in a kitchen; pots and pans, knives start flying towards him getting stuck on him as he ducks. ok - no pots and pans or knives here. But I did LOSE the magnet as it flew out of my hand. I had to search to find where it had lodged itself. Under one of the magnetic dampers near the DV505 base is where I found it. There is a little bolt (magnetic) on the left side of the main arm (as it has two arms). This is not shown on the tonearm diagram. Its helps with antiskating. As you get a few inches away from the post where the arm rests, the current draw is noticeable. The cartridge itself is about 6 inches away from this position which seems to be the last spot where a magnet field exists. On my ET2 arm the actual cartridge position because of it design is much further away. This got me curious so I sent an email to Masaaki at Dynavector asking about these magnetic levels. I’d like to say that Masaaki has to be one of the friendliest and knowledgeable audio people I have come across over the years in this hobby. Always responsive to my questions. I asked him for information about the “magnet force” levels on the Dynavector tonearm. His response. Hello Chris,
Unfortunately we cannot publish data of measured magnet current levels used the flux damper magnet in the DV505 tonearm. Only information is that the Magnetic flux density was multi-thousand gauss.
Thank you and best regards,
Masaaki
Dynavector
Multi – thousand gauss ? what does that mean ? Gauss Unit/Levels • 10−9–10−8 gauss – the magnetic field of the human brain • 0.31–0.58 gauss – the Earth's magnetic field at its surface • 25 gauss – the Earth's magnetic field in its core[3] • 50 gauss – a typical refrigerator magnet • 100 gauss – a small iron magnet • 2000 gauss – a small neodymium-iron-boron (NIB) magnet • 600-70,000 gauss – a medical magnetic resonance imaging machine • 1012–1013 gauss – the surface of a neutron star[4] • 4×1013 gauss – the quantum electrodynamic threshold • 1015 gauss – the magnetic field of some newly created magnetars[5] • 1017 gauss – the upper limit to neutron star magnetism; no known object in the universe can generate a stronger magnetic field[5] I am trying to figure out why Dynavector would use Gauss levels in the multi thousand range? Would they not have measured its affect on the phono signal ? From the DV505 manual - similar info to the previous posts. electro magnetic damper
This damper applies effect of eddy current, which is generated when conductor moves in magnetic field, and which obstructs conductor in motion. It has almost no damping effect on motion of non-vibrating tone arm, but is highly effective to vibration of arm, such as arm resonance. DV505 Manual Richard – can you tell us what type of magnetic damping you experimented with that led to your opinion of it? Position of the magnets relative to the arm, Gauss levels ? Dover - I believe you were using a fridge magnet ? which is about a gauss level of 50? Cheers |
Hi Thekong
Thanks for posting that pic and allowing us to be part of this !
What a cool setup with those armboards and counterweight. It appears that the rod is “welded” to the square which attaches to the spindle end ? These are grounds I have not stepped on. Richards comments about flexing are very interesting.
Can you tell us what cartridge you are using and the psi you are running ?
We have been discussing the advantages of the single, double, triple leaf spring counterweights here a lot. I am assuming you have a stock single leaf spring that came with the ET 2.5? Most of us I would think use the leaf spring counterweight. It would be valuable for me and others, if later on at some point; after tweaking and listening with your custom fixed counterweight; you could put on the leaf spring counterweight and tell us the differences you hear.
Anticipation builds. :^) Thanks again for including us in this.
Cheers Chris |
Frogman - I have been thinking about that too. Since that pic I have them on top of one another in one pillar. Will try that out. My TT setup does not allow for magnets on both sides as the arm is on a pillar. Look forward to your observations with them on both sides.
Richard, Dover, others - based on your experience if only using the magnets on the counterweight side of the manifold - can u tell me what the most effective arrangement was. I will try various arrangement as well as one larger magnet instead of few smaller ones. |
I think the home depot link blew the last post up like that.:^( Just want to clarify when I said. Richard – did you have the lead slug in your spindle when you were using the magnets and was it at 12 PSI? I want to recognize that you are running a custom setup spindle/manifold. My experiences have been with stock spindles 2.5 and 2.0. Still - I assume you tried magnetic damping with the lead slug and without ? Cheers |
Frogman
The less compliant double spring usually yielding a more controlled, defined sound with tauter and faster bass. More compliant springs have produced sound that is generally fuller, but less-well defined; fuller mids and lows, but less-well integrated highs. Frogman your observations mirror mine. Here are some personal impressions in my specific 2 rooms. BTW - Bruce has confirmed to me that adding a double spring raises the resonant frequency of the I Beam Counterweight. Two rooms set up with an ET2 and ET 2.5. First room The ET 2.5 is in a room with gear that I am able to pressurize easily and hear the bass nodes by walking around all on fours. I can locate where the bass is fullest and over powering. I can also find the spot where the nulls are. By experimenting over 19 years with multiple speakers I have found for this room only; the spots that give me minimal resonances at my listening chair, based on where I position the speakers. A key to my own audio madness 1) a dedicated room and 2) a listening chair that can be moved forward and backward multiple feet to adjust for soundstage/sweetspot differences between differently engineered music sources (whether they be on lp, cd, or tape) and different cartridges. Anyone that has ever heard a 420 str for the first time is aware of the stark differences in soundstage presentation it provides. I had to move my nearfield listening chair back a few feet from the first listen to the 420 str. What if your chair is up against wall..... I prefer the double spring in general in this first room. The bass is tighter as you say – mids and highs are clear, the bass nodes don’t last as long with the double spring. The triple spring was even more extreme in this regard. It became too lean however as I posted a couple of posts back. Second Room – much larger (adjacent to room one) An ET 2.0 setup with gear that provides for full sound through the mids and highs, but needs help with two subs for the lowest octave with certain music. They are Quad 57 speakers. I cannot pressurize this room no matter what I do – reason is - firstly the space is too big and open and 2) my wifes TV room is close to it above and adjacent to it a ways. :^( I prefer the single leaf spring in this second room. The bass is fuller as Frogman said, but in my case as the space is larger it allows IMO for bass waves to dissipate, not bounce around causing problems. This also means harder surfaces can be used in the room to allow for clearer highs. For me the room/space dictate our preferences above everything else. TORQUING OF THE ET2 LEAF SPRING USING DOVERS METHOD I untorqued the single leaf spring in room 2 last night per Dovers recent post and the sound seemed to get even more fuller. The change was noticeable. I will experiment more with this. Dover thanks for this detail it is really appreciated. Heath Robinson Belt Drive I really like Grantn's sense of humor :^) Welcome to the thread Grantn. I have learned alot from Richard and Dover in the last few weeks. Cheers Chris |
Playing with magnets. From yesterday the pic shows two magnet setups The top setup is superior. Three on top of one another not alongside each other closer to the spindle. Dover will try the Eddy magnetic clamp later today. It is just 9am here Sunday right now. If you look at the bottom pic you can see I do not have alot of space to work with for two magnets either side of spindle. I will clamp a small platform there with some blue tac today to allow me to put two magnets up closer to the spindle and on either side of it. Will pick up some square magnets today to give the S-N Beam N-S ------O---------- Beam/Spindle S || N--N || S---- Magnets Being an IT guy I hope you are impressed with my illustration. I took a cue from you. Cheers |
Dover
would be good if you could test the eddy current clamp I describe in the above post, using 2 magnets clamping the tube at one point in "S-N Beam N-S" configuration. Ok wanted to get this out so excuse any errors. here is the temporary setup pic (lower one) showing the same pole magnetsproviding eddy currents from both sides of the spindle. The Blue tac marks the north poles of the magnets. Will be making the magnet platform out of something else. Here is what I did today instead of house chores. Went and picked up a package of the magnets you see in the pic. There are 8 in a pack for $3.00. Thin rectangular pieces. I took two – put a string between them – let the opposite poles hold the string. I then let it hang very gently so one of the sides pointed north. Either it remains as north or it started turning to get to north. I marked the north poles with the blue tack you can see. I guess you can see I like this blue tack stuff. I cut a temporary piece of wood high enough to just clear the spindle and placed the two magnetic pieces on wood. The magnets could fit just below the spindle right now if I slid them across. With this setup then could be raised and placed on either side of the spindle too. Dover
When positioning magnets for eddy current dampening, closer is not always better, the magnetism has nodes that vary up and down with distance. The distance that can be seen between them in the pic; is the minimal amount allowed in this setup. Any closer and the magnet pieces with the same pole magnetic repulsion start pushing each other off the wood. Sort of like my twins - sorry had to throw that in. They are just resting on the wood. This is how my TT works – magnetic repulsion - that produces levitation. So all of this feels like I am playing on home turf. Impressions - To describe what I hear would be just another opinion and I am no good at describing sound. Plus all our setups are different. So lets use a car analogy again. You can buy cars that have buttons that give you sport – normal – and cushy suspensions. You push the button to select the ride type based on road conditions. The different LP/Records being the different roads here. What if a car was made that did the switching for you automatically. If the road got worse or changed to gravel, the suspension changes on its own and cushions it. The resulting ride would be quieter and smoother and you can hear yourself talking with the other passengers better. Thats more of the sense I am getting with this setup. Records are quieter, highs more refined similar to past magnet damping, but now it seems more consistent/stable. This is only based on 6 or 7 familiar lps. All ET2 tonearms owners should try this. If you have some records that are more off center, sound more splashy to you then others - try them first. Once I have settled into the sound I will make a pillar for the other side to hold two similar magnets at the start of the manifold and listen again. Frogman looking forward to your impressions as well as others that try it. Richard – I know you tried many variations of magnetic damping. Did you try this same pole magnet clamping style ? Early on but am not able to detect any eccentricity or excitement in the spindle yet. Music seems to be very controlled, stable. ET 2.5 spindle 19 psi. Thanks for the suggestion Dover. Cheers |
I reached out to Bruce to get his opinion about the shims idea for the manifold. Look forward to his response and will post back what he says.
Cheers |
For me the room/space dictate our preferences above everything else. Just to be clear - my statement is very "biased" and it is based on my personal audio hobby experiences over the years. cheers |
Dover - I always thought shagging around with the system was housework Dover – What is your definition of shagging. If you mean ‘experimenting’, its a release for me along with a couple other hobbies from staring at a screen for 30+ years in IT. The problem is when I get on to something I disappear. I promised my wife yesterday if she let me play with some magnets I would watch the Oscars with her. Re: The Oscars - She thinks I am like the guy in Silver Linings. I saw it a month ago – some parts hit home. I tell her my meds are the music, running ...and a little red wine. Out of interest do you run your Verdier with or without the ball inserted? My opinion on the setup ball was expressed here. setup ball |
Ketchup
When you had your three magnets in a row, did you notice any difference in sound as a record side progressed? Ketchup – the way I used the three magnets in a row the effect was very subtle, so too hard to answer the question sorry. In a tower three on top of one another the effect is more noticeable in system. My spindle is sitting high compared to where the magnets are when in a row. I will say lack of knowledge about the magnets prevented me from experimenting further. The discussion here and the experience with the Dynavector arm made me want to experiment. |
Dover/Richard/Frogman and others trying the magnets.
Another short listening session today then I had to head out for the evening. My impressions are mixed now. Not sure what to think. I really feel with myself, when tweaking like this what I can hear can depend alot on my mood going in, and how the day went. This is why multiple sessions are required for me over time. I have added more magnet slivers (4) to each side. Will have a few more listening sessions this week.
Richard/Dover
I used to enjoy “shagging” fly balls during practice playing baseball when I was younger.
Cheers |
RichardKrebs
To everyone..I'm sure that you have experienced this. Last night's listening was great. All the planets seemed to align. So what causes this? Clean power? Just the right room temp, humidity? My own state of mind? Off topic, I know, but I am curious to read your views on this. Richard your NZ last night is my yesterday still.... I believe in the one and almighty, and in the things that are out of my control. He giveth and taketh away. Yes I am talking about the local hydro company. This is an audio gear site. I was very aware of the power limitations I had, and their effect on my systems in the big dense city. I feel kind of blessed now that I live in a rural area with an abundance of clean, raw power. Sometimes on a few occasions there is not enough (hot humid july/aug nights). Other nights, more often, there is too much above 120v. When the number on the gauge reads between a certain range I have come to know that good things can happen. It then depends on my own mood. Humidity helps. There is more grain in the music for me when the power reads above 120v. Looking forward to converting my table to battery soon. All Power Conditioners I have tried made the bears sound pleasant but like they were on meds. No thank you for the amps. The OTL's coming have their own line conditioners designed for them. |
The base of the ET2 is mounted with one bolt and has 3 grub screw spikes for proper leveling on any surface or armboard.
We have discussed removing the aluminium shim. If your worried about marring your surface, Dover had mentioned filing down the grub screw points.
Can the bracket be improved or .......removed...? Another material? It is the part that holds all of the goods.
Cheers |
correction last post - I am in my 10th year now with the ET2's. When this thread started it was 9 years. lol. |
very interesting discussion guys. I am personally going on over 9 years with the ET2’s – never had a problem with a cartridge. I think I represent a typical music lover – meaning - I own xxxx records. At any one time there are xxx in 4 or 5 rows on the floor against the wall in my room that get cycled. Now none of them are eccentric enough to cause the spindle to move around like crazy. Most of the time I can barely see any movement in the spindle at all. I’d have to look really hard. Very interesting discussion on the various air bearings. It should be noted that of the ones mentioned so far , the Kuzma and ET2 I believe are the only two that can be mounted on any TT. There is the Terminator too (it seems from pictures/videos to occupy alot of space on the TT?) Maybe DG can elaborate? Its a BIG DEAL in my book to not be TT dependent. And fwiw - Any tonearm comparisons should be made imo mounted on the same table as this is a hobby about resonances and vibrations. So I have to ask here - Richard, Dover, Kong, others ..... what kind of records are you guys actually playing that you are so worried about eccentricity of the record ? I refer back to this post with data from the ET2 manual. http://forum.audiogon.com/cgi-bin/fr.pl?eanlg&1325551242&openflup&372&4#372Specifically the wording. This means that any given cartridge works against lower horizontal forces in the Model Two tonearm (.1 gram or less) compared to a conventional arm (.2 grams/gram vtf). These figures apply if you use records that are not severely out of round. If you like to play severely eccentric records, ones with runout of greater than 1/8”, then we suggest you use a low mass pivoted arm. --------------------------------------------------------------- Richardkrebs - We went on to talk about potential problems with cantiliver flex. His response was the resonant frequency due to the combination of a typical low compliance cartridge and horizontal effective mass was in the region of 2.5 -3.5 hz.(this has been published by them elsewhere), this is well above the 0.55 or 0.75 hz for 33 or 45 rpm eccentric records. Therefore the cartridge does not "see" this movement. Richard , so as shown above, Bruce has measured the lower horizontal forces in the Model Two tonearm (.1 gram or less) compared to a conventional arm (.2 grams/gram vtf). Are you able to get us the actual “lower horizontal force number” in the Kuzma Airline from Mr. Kuzma. I am very interested in this number – this is where the tire hits the road to me, no ? --------------------------------------------------------------- I have to admit something here to everyone as well, since I have been giving the discussions we have had thought. I really like the fact that the ET2 does not put any constraints on me as far as the type of cartridge I can play, anytime and anywhere. I can put on a Sonus Blue Gold with a single leaf spring, • Dynamic Compliance: 50 x 10-6cm/Dyne. • Tracking Force Range: 1.0 to 1.5 grams. than switch it over to a triple leaf spring beam with my XV1. Is this flexibility not worth something ? sorry for the following asterisks but this "IBM dos like" based forum does not allow for bolding and colors. *********************************************************** Is there another tonearm in existence that allows for the above to occur regardless of cost ? *********************************************************** btw - If I do find a record I like alot - that is so off centered (runout of greater than 1/8” as Bruce says) and cannot be replaced. Why not just drill out the center hole and use a heavy weight on it ? Richard/Dover/Slaw - is this not possible ? You guys have discussed drilling out of holes before.... Cheers |
The ET2 gooseneck – the part that connects the armtube to the spindle is made from Carbon Fibre. I asked Bruce about making one in aluminum. It can be done in a special run if there is enough interest.
I told him I would find out how many are interested. If you have an interest you can contact me at
bcpguy(at)bell(dot)net
Cheers |
Ct0517 - We know the heavier ET2 armtube affects the horizontal mass as well. this was worded badly. This thread is too old to allow for corrections. I wanted to say the arm wand weight lighter or heavier, affects both the vertical and horizontal inertia at the same time. This is really important. |
DG - thanks for that info. Curious if Frank K happened to mention to you what his favourite tonearm was - of the ones he makes. |
