Hello all,
Had recent email exchange with Bruce. Told him rumor was he was considering a run of long I beams and if he was to please put me down for one. He said he was thinking about it. Maybe a little encouragement from us would help?
Re cartridge loading, I'm not at all disappointed with what I'm hearing but John kind of talked me into trying the 100 Ohm loading. Going to give it a shot to see what I hear. Cheap and easy tweak.
I think within certain limits cartridge loading is listener and recording dependent. I listen to a lot of small combo jazz. I want to be able to hear cymbals that sound like brass (not steel) shimmer and extend off into forever. But when you spin up a trumpet like Miles, you don't want it ear piercing.
An example of recording dependent:. I really like the great sax players. I think Paul Desmond was one of the greats and own many of his records. I read a story about Desmond years ago that said he had an obsession about not being able to hear the spit in his reed. He insisted the recording engineers roll off his feed. As a consequence I often raise VTA when listening to Desmond. Even though his great RCA recordings with Jim Hall were extremely well done, you almost never hear the air across the reed like you do on a Ben Webster recording.
And as I mentioned earlier I believe, from a listening perspective VTA and subwoofer tuning are interrelated. If you raise VTA for top end extension, if necessary, you can inch up the sub to fill in bass a little. Can't get carried away or bass will get tubby but just a little can help with foundation.
Again, however, I think once you get your system well set up a lot of this boils down to listener preference.
Cheers,
Harry
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Hi John the diagram in this link came from Bruce. the setup in that pic is mine. Diagram - We have two vertical plates/walls, a roller in between and four horizontal bolts holding it together. It makes sense that all four horizontal bolts should be at the same gap for even operation. I have talked to Bruce before about the .02 to .06 range and it is a personal choice. I prefer firm .02 as I do not use the VTA a lot with my cart / preamp. As we know going .06 is the gap opening extreme value - also the least firm action. So action on the lever is loosest/smooth. If the VTA is working properly and someone wants to literally VTA on the fly - as the record plays - looser is easier. The Lyra cartridges sound a bit bright and lack bass at 47K. I hear a real improvement in freq response with lower values. My ARC ph-5 has values of 47K 1K, 500, 200, and 100 ohms. I use 100.
Those load values are true of the latest ARC Ph9 as well. 47k, 1k, 500, 200, 100. My SP11 MKII uses values of 47k, 100, 30, 10, 3 It's been my personal experience that the phono circuit design into single load values, needs to be ultra low noise in design, to be able to use single digit values. I assume ARC chose higher values on their newer phono stages/ preamps designs due to the customer / cart requirements that exist today. Regarding how your Lyra cart reacts to 47k. Maybe this is cart specific I don't know, don't own a Lyra cart. fwiw I can use 47k on MC's with no loss in frequency and if it is a brighter recording, the SP11 has adjustable Gain - I can dial it down a bit. Takes out the brightness. Get it right and I can get the band sounding like they are at the Mic. On regular records 100 loading works fine, and produces a good Studio like sound. I don't have a remote but the SP11 is parked at the side of me within reach. Cheers Chris |
Hi Chris,
I checked with Bruce about the gap between the VTA mechanism and whatever.
He said "
The gap does not need to the same between the VTA shaft bearing blocks and the manifold housing. The four screws should not be torqued down to close the gap, the average should usually be about.02 to about .06 inches. If the VTA mechanism is working correctly, the torque on those four screws should adjust the stiffness of the motion of the VTA mechanism and not tightened to the point that it stops."
Just thought everyone ought to know his opinion.
-John |
Hey Harry,
I know that resistors aren't directional. I would check the type of resistors in the original CAT plugs, and buy the same quality. You probably need metal film resistors (1/2 -1 watt) 1% tolerance. Definitely 100 ohms and if you have enough plugs maybe a 500 and a 1000ohm resistor set. I usually buy 5-10 for each value, and measure each set with an ohm meter, -digital if you have one. Match up pairs with closest val;ues for each set. Buy them from Mouser electronics on line. They are very cheap, and shipping will be most of the cost. That's why you buy more than you need. If CAT uses Vishay resistors, I would buy that brand, but probably not.
By the way, can you solder, and do you have any silver solder? You can get silver solder from "Michael Percy" on line. Google him.
Hey Chris,
The Lyra cartridges sound a bit bright and lack bass at 47K. I hear a real improvement in freq response with lower values. My ARC ph-5 has values of 47K 1K, 500, 200, and 100 ohms. I use 100.
-John
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Hi Harry (and John)
what happens when you guys run your Lyra carts on 47k load ?
Chris |
John,
Tried to contact Convergent Audio Technology without success. All you get is a recorded mesage telling you their business hours. They build great products but are very customer unfriendly. So I'm getting brave. Ordered some nice looking RCA plugs to build my own cartridge loading plugs. Do you know if resistors are directional, i.e. Is there a plus end and a negative end?
Thanks,
Harry
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Thanks again frogman,
I'll be interested to hear whether the double arm board performs better than the single with spacers. I'm going to try it first w/o the damping. I understand the two boards will not mate perfectly across their entire surface area but, then, there isn't any damping between the metal sub plinth and the single board either. Then still again no one ever argued the HW-19 can't benefit from tweaking.
Harry
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Good suggestions, Harry. I sent you the board via USPS yesterday. I also included a piece of the material that I mentioned previously. If and when you get around to trying the "double-board" I would try with and without the sheet between the boards. Resonance and its effects is a crazy thing and the two boards, as tightly together as they may be held together, will still resonate as thinner boards in, at least, parts of their total surface area; as flat as these boards may be cut, they won't make contact with each other over their entire surface area. The sheet between them may help them act "as one" and will introduce some dampening which may or may not be beneficial in the context of your system and your tastes. At least, that is how my twisted brain considers this kind of thing. Please report any impressions.
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Good evening,
Follow up report. While I will not claim to have become an ET expert, after about two months of tweaking and upgrading I can offer some suggestions on listening to your tweaks.
1. For those of us who use subwoofers, the tuning of your subwoofers adds a whole additional layer to what you hear. My advice here is to either get your subwoofer settings where you want them before you tweak/upgrade your ET or disconnect your subwoofer and listen for a few sessions before tweaking your ET. Then go back and readjust the sub before you pass judgement on your ET tweak. A tweak you think was one step backward may well be two steps forward when you get your sub tuned back in. VTA setting and sub integration can be interrelated.
2. When tweaking your ET pick 2 or 3 of the LP's that you rely on for testing your system and stick with them until you are happy with the result. Do not start sampling your record collection before you are satisfied with your work. Few of us have record collections comprised of only excellent recordings. If it was a lousy recording before you upgraded your ET, it will probably still be a lousy recording no matter how amazing your upgrade or tweak.
3. Be disciplined when you upgrade. Do one tweak or upgrade at a time. Perform only those tasks necessary to complete the upgrade or tweak you set out to accomplish. Do not give a bolt or screw that is not part of your upgrade one last twist before listening. I.e. Resist the urge to give that loose VTA block bolt a little twist for good luck.
These suggestions are probably second nature to you old hands but I think they can save a good deal of frustration to those new to ET upgrades and tweaks.
May you spend more time listening to your music than your system,
Harry
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Its not LIKE we can still can, its we really can !
ET-2 is a proud title for any man . |
John,
No offense taken. I don't consider any suggestions meddsome on this thread. I very much appreciate the suggestions. Think I'll noodle around the Internet to see if I can find some loading plugs.
............................................
shubert,
Love the ET second class analogy. Brings back fond memories and, yes, it's like we can srtill hear what we're not supposed to be able to hear any more.
Cheers,
Harry
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vpi, I’m a lot older than you and been around a lot of jets as well.
I know my hearing is way down but the brain compensates very well if it knows losing music would affect your overall stasis significantly .
Nuro science had advanced a thousand fold on stuff like this with ground-breaking research from Oxbridge in UK .
Glad I never saw an ET-2 ,I’d really be nuts . Of course ET-2 really means Electronic Technician Second Class ,USN . |
Lyra recommends between 90ohms and 47Kohms for your cart. I really think you would benefit from somewhere in between, especially if you're trying to improve your bass. The bass will improve while the treble gets less strident as you decrease the load. (going from 47K on down) You would appreciate it since you've got the arm dialed in. Can you sling solder? I would ask Ken where to solder in some loads. He has no doubt helped other owners of his fine preamp with the same issue. It's a very common problem for vinyl fanatics.
Sorry for meddling, but just trying to help, since you're trying to get the max out of your setup.
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Well, my CAT preamp has RCA inputs into which I can plug loads to change the loading but the only loads I have are 40 and 80 ohms. I've tried them both and found them to roll of the highs a bit much for me. But, then, there is my hearing loss in the high frequencies. Most of the bloggers I have read relating to the CAT seem to prefer it straight in at 47k. I do wish I had the luxury of remote to compare loading from my sweet spot. Alas, I think I'll be buried with my CAT.
Convergent Audio is a rather unique company. They have no web site and no published email or phone number. I don't believe they even advertise. Ken Stevens is rabidly protective of his dealers and forces all contact through them. Makes it difficult for the tweakers among us. Unlike, ET you can't just pick up the phone and say, "Hey Ken, send me down some loading plugs."
The company was not that way in its earlier days. In fact, I actually spoke with Ken a few times shortly after purchasing my preamp. I'm not denigrating the company. Ken builds a super product. At the risk of alienating others on this thread, the only preamps I've heard that I thought were in the same league are the ARC SP-10 and SP-11. I do confess to have an interest in the ARC SP-20. I need to get down to Atlanta to see if I can listen to one. Purchase would have to wait another year or two for prices on the used market to come down some.
Harry
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Hey Harry,
I asked what load you were using on the Delos because my Kleos is very similar.
I found 100 ohms worked best for me. Very much higher made the highs get a touch strident. What have you found? It was easy to switch loads with the ARC ph-5 on the fly with the remote, and I could tell instantly which was best.
John |
Hi John,
I'm using 1 ft long pure silver unshielded, cotton insulated interconnect from junction box to my CAT SL-1 which is supposed to be 47k ohm. The IC is made by a fellow in Texas and is sold only on eBay. I don't know it's capacitance. It should be pretty low.
Cheers,
Harry |
Hi Frogman,
Guess I didn't know the platter height was adjustable. I'm about 1/4 inch + above the plinth. It would have been interesting to try. Not possible now unless I lower the arm board because my platter extends just a hair over the arm board and the clearance there is very small. I must confess while I've read about bearings and thrust plates for years related to TT maintenance, I'm not sure I know what the thrust plate is or how to adjust it. Good lord, not something else to adjust?!
I too am rather surprised at what I can hear. I'm 73 and spent 5 years as a Naval Flight Officer so I do have some hearing loss. I doubt I have anything left above 8-9k hz. That said, I can hear room, air and low level detail on well done recordings. Guess it is the harmonics. I suspect my hearing loss contributes to the difficulty I have with VTA adjustment. I think sometimes in search of the higher frequencies I tend to push the cartridge nose down too much. But I'm learning.
Cheers,
Harry
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Hey Harry,
I'm happy as well that you're enjoying the arm. By the way what loading are you using on the Lyra Delos cartridge? I'm at 100 ohms with the Lyra Kleos, but using some pretty low capacitance pure silver interconnect (old AQ diamond X2) from the junction box to my phono preamp ( total capacitance 60 pf using Bruce's standard harness). -Lyra states their cartridges don't do well with high capacitance cable. So. I'm trying to keep it as low as possible. At 100 ohms, the base is incredible and vibes come thru perfectly.
Regards,
John |
A lot of passion, indeed; and, I am impressed at the fine level of nuance that you are able to hear and able to describe. Harry, no shame due for wondering if raising the arm board might be a step backwards in transparency; it's always a possibility that would be hopefully offset by the gains from proper VTA adjustability. Sometimes we have to give up a little somewhere to gain something more important elsewhere. Glad to hear you don't think you've had to give anything up and the magic is back. I did have a thought about something that I am surprised we all overlooked (I think) when discussing your VTA issues. The HW19 MkIV platter itself can be raised or lowered by turning the bearing's thrust plate. When I had the MKIV I had the platter just barely clearing the table's top plate. How much clearance do you have? Lowering the platter may get you some more (or easier) VTA adjustability. Btw, the extra armboard will go out this morning; had to get through a very busy weekend. Let us know how it all works out. |
John,
I'll probably end up getting the aluminum base sooner or later. Right now I've been tweaking and upgrading for over two months and have it where I'm very pleased with the result. So for a while I'm going to subscribe to "if it ain't broke don't fix it."
Chris,
Nice down here in the lower colonies too. Gonna have to plow the garden soon. Audio passion? How polite......Actually, I'm just retired and OC. The best description I can give to where the system is now is while I'm trying to listen to the system to make sure the setup is correct I find myself listening to the music instead.
May you all have spot on VTA,
Harry
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Beautiful day been working on the Boat . Check out this picture showing the internals of a destroyed ET2 VTA block. See Bruce’ patented design. Destroyed VTA BlockFor a full picture of damage inflicted by this audiophile, see Pic 33 on my virtual system. The problem with the one in this pic. The VTA bolts were closed, jamming the aluminum roller to the track. You can see how the aluminum roller caused a bald spot in the track. This VTA block will slip on that section and is no longer any good. The VTA blocks are all made on an individual basis with their specific manifold. For this reason Bruce can’t just send you another VTA Block if it has been destroyed. So, when buying a used ET2 - this is the part, the VTA block, that you need to verify is in good shape because you can’t see it. Ask the seller to measure the gaps for you. If they are factory settings as discussed here, it’s a good sign it was not messed with like Harry said Bolts uneven in gap, along with causing the VTA to not be accurate, will also put uneven pressure on the track and WILL wear the teeth out unevenly that the aluminum roller tracks. I keep all the 4 bolts the same in gap. open the gap more for less firmness but keep the gap the same on the 4 bolts. Harry - glad your magic is back. You have a lot of audio passion sir ! |
Thanks Harry,
I still think you should get an aluminum base. It's much more rigid and Bruce will cut you a good deal. After I got mine, it took me six mos to change it out, because you almost have to start from scratch, setting the arm back up. I didn't want to do the work at the time.
Cheers,
John |
Hey John.
Actually, there are two numbers on Chris' feeler gauge, .020 followed by .508 mm which is the metric equivalent of .020 in. It is very hard to read from the picture but it is the same as the feeler gauge I have. I don't know if you bought your ET II new but if you are sure nobody has played with the top two bolts on the VTA block, you probably still have the factory setting and are good to go.
Harry
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Hey Harry,
Your explanation is very helpful. I'm not sure I have an issue with this as I've never messed with the top two bolts out of fear. The manual just says to adjust the bottom two. However, as I see that pic from Chris, the gap gauge he is using says .02 mm, and not inches. Am I reading it wrong with my bad eyes, or did you make a mistake on that info? That's a considerable difference! -smiles.
John |
The Magic is back! As mentioned, after playing with VTA everything was sounding very nice last night. This morning I followed Chris' diagram and reset the space between the VTA block and manifold housing with the .020 in. feeler gauge, reset VTA, leveling and checked tangential tracking. As soon as the I dropped the needle back in the groove the improvement just jumped out at me. Transparency was back in spades. All of the subtle inner detail that makes analog so enticing had returned; like Clapton's finger plucks on "Unplugged", Carol Kidd's breath and the air across Ben Webster's sax reed. I'm still trying to visualize how the small amount of tinkering I had done to those two top VTA block bolts could have thrown the arm so far out of whack. But it certainly did. Thank you, Chris.
And shame on me Frogman for suggesting that raising the armboard on the washers could possibly have contributed to my problems. Not the case at all. This fix just gave me back VTA adjustment range with no negative side effects I can detect.
Now that I'm done with taking steps backward I can report my observations on the magnesium arm wand. If I were to reduce my impressions to a single word it would be "control". It is as if the arm grabs hold of the LP and says "gotcha". Things firm up, leading edges become more defined, and the space occupied by individual instruments become more defined. This was an improvement well worth the cost.
John,
My understanding of the bolts in the VTA block is that the top two attach the block to the manifold housing and the bottom two and only the bottom two should be used to adjust stiffness. The top two should be set to where there is a .020 in. gap between the block and the manifold housing and never touched again (see photo and diagram on Chris' virtual system page). You should not try to tweak the top two bolts as I did. After setting the top gap to .020 in. you can play with the bottom two screws to adjust stiffness if needed. Listen to me talking like the expert after I screwed this up on my arm and needed Chris to get me straightened out. :) I'm sure Chris will correct me if this explanation is not correct.
Happy listening to all,
Harry
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Thanks a lot Chris,
Now I have something else to worry about with this arm. Could you kindly elaborate on the gap between the manifold housing and VTA adjuster? Should the gap be the same at all 4 bolt positions or what? I thought that they simply adjusted the stiffness of the VTA mechanism, and had nothing to do with the arm's geometry. -Simplistic thinking on my part, huh?
Thanks, and g-day
John |
^^^^^^^ Ah - the VTA Block Harry et al. So special the worm gear system in the VTA block has its own patent. Is the reason this tonearm is the only one that doesn’t change VTF, and other settings like all other tonearms, with VTA adjustment do. Still remember the look on the face of an audio acquaintance from years ago, when I told him his $10,000 tonearm changed the VTF every time he used it. He was quite detailed, anal and used to use a digital usb microscope to set VTA/SRA. He was not happy. He had that look like someone had swindled funds from him. Tonearm manufacturers will never bring this up. Its the dirty little secret. The only one (Professional) that has mentioned it on this AudioGon forum is Johnathan Carr. He also discussed in that post how the ET 2 is the only tonearm that does VTA right. But to get it right is not so easy. Factory settings need to be left alone sometime; and as we know Audiophiles like to tinker and mess with design, and sometimes...not realize what they have done. We have all done it? ********************** The ET2 VTA design is probably also responsible for the biggest ET2 setup issue. And I blame Bruce. His documentation should say don’t mess with those bolts that are set at the factory, (unless you know what you are doing) but in nicer words. Lets face it - A Come to Jesus time moment..... as we used to say in my line of work. Everyone that has bought this tonearm used, and not already setup on a turntable, in the last 5-10 years, and did not read the manual (too intimidating). IMO most of them, have turned those horizontal bolts to help in setting up the tonearm on the straight line. THEREBY - throwing their ET2 out and creating a mini version of the Leaning Tower of PISA. Too dramatic ? So IMO the manual is at fault to start. Such a special process that is open to tinkering should have its owned section with warnings. If they told you, your computer needs a change made to the registry files to fix a problem; would you make those changes yourself ? Depends on your knowledge of course. Yet, adjusting those VTA bolts has a similar effect on your tonearm performance if not done right. It won’t work as designed. Is it any wonder that past owners who reach this point, with no instructions in the owners manual - have shut the VTA down - closed it - and said the hell with it. Never knowing what they did ? Just one of this audio hobby’s mysteries. ********************** The proper way to check your VTA torquing. (Setup on the table or not) "Pic 34 on my virtual system" ********************** Turntable "Factory" Drilled ET 2 mounting holes. The holes drilled into armboards at turntable factories are not all that great. If you have a factory drilled armboard mounting hole. Re-check and re-torque if necessary your ET 2 VTA bolts. Now tell me, ......does the tonearm still track the straight line ? Imagine If your ET2 is mounted on a 20 lb isolated armpod. All you have to do is move it to the table wiggle the base around for the straight line alignment and you are done. |
Thanks John. No I don't have the aluminum base but I have a pretty hard acrylic armboard and the balancing pointed screws are nice and tight. But good thought.
Chris, I was mistaken there are not two pieces to the VTA block there is a line across the top on both sides of the block that I thought was a seam. On closer inspection, those lines appear to be marks from a mold or part of the manufacturing process. So....it is now clear from your picture and diagram that the .02 gap is between the block and the manifold housing. I suppose if this gap were not the same on both sides of the block adjustments to VTA could be different from one side of the block to the other and this would change the leveling of the manifold housing. I'll check the gap on both sides tomorrow.
Harry |
Harry, I can't remember if you have the aluminum base and whether the three points of the base are on wood or metal. The points can dig into a nonmetal armboard throwing it out of level when you change the VTA. -Just a hint.
John |
OK, I think I've got VTA set right now. Cymbals are clean, soundstage back and I can hear the breath with vocalists and in Ben Webster's sax. In playing with VTA, however, I seem to have run into another issue. It appears that when I adjust VTA it throws the arm out of level. Yes, I know the HW 19 is notorious for shifting balance but I don't think that is the problem. I have a bubble level on the arm board and it stays level. Just whenever I adjust VTA the arm seems to go out of level. I've checked and tightened the two screws (pivot and lock) that hold the manifold to the post but that doesn't solve the problem and the VTA lever moves smoothly so I don't think I have chewed up the VTA block. Any suggestions?
Chris, I saw your picture about spacing (.02) but I am not sure which joints needs this spacing. There are 4 screws in the VTA block (2 up and 2 below) and there appears to be two pieces of the block that fasten to the manifold housing. I can't determine from your picture whether the .02 gap is supposed to be between the two pieces comprising the VTA block or between the VTA block and the manifold housing. Could this spacing be the source of my issue?
Thanks,
Harry
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Hi Frogman,
No, I wasn't yet ready to blame the raised arm board. My dascription of positive response was probably the wrong word. After a very brief listen it just wasn't bad. Probably a psychoacoustic response. You know, when you've done a tweak designed to improve your system, you believe (at least initially) that it is good. Longer listening revealed loss of transparency and focus, shallower soundstage, sandpaper cymbals and loss of impact. Precisely the symptoms you would expect when VTA is way off.
i started playing with VTA resulting in substantial improvement. My problem (other than being a klutz) is the only straight lateral line on the Delos is the top where it meets the tonearm. On top of that my gear is all in a shallow closet so I can't get my head back far enough to sight for level.
By bed time I was pretty pleased with what I was hearing but won't render final verdict without more listening.
Thanks,
Harry
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Hi guys, just wanted to warn everyone about a negative interaction I had with some clown who has an ad posted saying he wants an ET two tonearm. I answered his ad as I have two of them and right now I am using neither. The one I offered him is in perfect condition and I paid a tech $400 to put a straight shot of top-of-the-line cardas wiring going to their termination block. The VTA block works perfectly and it is in excellent condition. There is also two pumps with it that I have seen go for good bucks on eBay. Well he offers me way less than my asking and starts calling me an idiot and other names when I tell him never mind, good luck with the search. He tells me my pump is worth 40 bucks and as proof posts a pic of one on eBay that is not even remotely the same thing. Then he tells me the wiring is $53. Heck if he has a technician that will put a metre of top-of-the-line card ass wiring on for that money I want to know! He says that's the trouble with us audio files we think her stuff is all worth way more than it is. Just wanted to put a heads up on this forum as there could be a good chance somebody from here would offer to sell him one. I would suggest not to bother as he's obviously looking for champagne on a beer budget. And nobody needs the verbal abuse from some clown on the Internet. |
Before you attribute any perceived changes to the raised board make sure that you first make the comparison with the VTA EXACTLY the same as it was before you raised it. What made your initial impression positive? |
That would be non-thick records. You know, the ones we used to pay a few bucks for.
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Hi Chris,
I've not been dead in the water. The existing setup with mag arm was fine on non-think records. I just didn't have any room to raise VTA any further. While waiting for Bruce's screws and Frogman's extra armboad I tried Frogman's suggestion of placing washers between the arm board and the metal sub plinth. In my case I used 1/4 in. tall nylon spacers. Had to get longer screws to screw the armboad back to the sub plinth but it was an easy fix. The 1/4 inch was just the right amount of extra height to gain back VTA range. I've only been listening a short time but my initial impression is positive, however, I think I've lost a little transparency and focus. Perhaps with the arm board sitting up on the spacers rather than secured tightly to the metal plinth I'm getting a little resonance in the arm board. Or perhaps it's the nylon and I should have used steel washers as Frogman suggested. The jury is still out. Want to do some more listening.
Im beginning to believe there is no life outside of the ET arm 🙄 |
Besides: How does it sound? Hi Pegasus Do you want the description compared to the other turntables ? or do you want to know how certain albums, songs, sound, when I am in a certain mood, with a little drink, and with the full moon in play ? :^) But - looking at physics - how could these holes provide isolation from either acoustically transferred noise (which, if they’d change at all, would rather increase) or structure borne noise. Let’s forget the massive cavities under the motor and armboards for a moment and concentrate on the build itself - Review the pic I posted. Look at the alternating layering. The design is meant to dampen/absorb resonances. The armboard is connected to the plinth in four spots where the bolts go in. Armboards can be any material - interchangeable- mine came as a hardwood. Note: Some, build a plinth for an idler one time, and then modify it, or leave it alone. JN has gone through XX maybe XXX ? plinth builds to get to where he is today with his tables. Just saying. He does have passion. An owner of such a table does "not" think about changing any part of it because of the road it took. You would be messing with it. It is, the table, based on his vision. ************************* Hi Harry - do you think you will be up and running soon ? Chris |
those nasty motor wheel - rumblings. I was actually amazed about how they disappeared behind the not inconsiderable LP pressing and cutting lathe rumble (the latter sometimes audible too), and behind the superb musical information & drive. I expected problems, but... armboard holes are helping to provide tonearm isolation
I assume Jean Nantais has pretty good reasons and convictions why he does things the way he does. But - looking at physics - how could these holes provide isolation from either acoustically transferred noise (which, if they'd change at all, would rather increase) or structure borne noise. Besides: How does it sound? |
The Lencos plinths empty rooms are not for controlling resonances - they are for ventilation, as the motor, a shaded pole motor, has very low efficiency and consumes *35W*...! Pegasus, that picture I linked in the previous link is not the motor hole, it is the armboard HOLE :^) And there are two of these massive armboard holes going through this plinth. They are separate from the large cavity below the motor assembly that you reference. These armboard holes are helping to provide tonearm isolation from those nasty motor wheel - rumblings. See pic 29 on the virtual system for the whole table pic. |
Hi Chris! I accidentally grew up with a Lenco B55 (practically same technology as L70/75/78) and a Thorens TD 124. These were the first victims of my brothers and my audiophile interests - we dismounted and reassembled them. I was more impressed by the ingenuity and elegance of the Lenco - *and* I still remember the sound as very upbeat and vivid, memories reaching almost 55 years back! Much more so than my slightly lukewarm memories the TD124, I'm sorry to say...
The Lencos plinths empty rooms are not for controlling resonances - they are for ventilation, as the motor, a shaded pole motor, has very low efficiency and consumes *35W*...! I rather think that in the end this is more of a weak point than the idler wheel. My impression is that the vertical low mass idler wheel is (within the context of idler wheels) a very good idea. The weak point there is a) the steering of the wheel with kind of a rod with limited stiffness and b) the exact positioning relative to the conical axe of the motor. But...
Rehearing the L75 in a friend's (superb) system with modded Avantgarde Trio etc. etc., after years of listening to a Well Tempered Signature, then a Funk tt with Funk arm was a revelation - already with a simple plinth. Of all "real existing" turntable platforms it is in musical, timbral, dynamical and coherence terms almost in another league - and it is a "stone age" concept. It really was a jaw-dropping experience. ca. 1980 I *never* considered re-using a Lenco or a SL1210). I was a *real* audiophile, who had to use a belt-drive... I bought a Thorens TD 126 - one boring lifeless turnatble. Then came the Rega 2, then a Walker CJ55. Both really much better in musical & colour-terms, then the WTT Signature in my system too.
Funny how I moved from "scientific" musical medicine back to "evidence based" or empirical musical medicine.
Today I use a much modded SL1210, which has a slight advantage in purity / stability of upper midrange timbres.
In Europe Pet Reinders is the Lenco "guru". I can do without gurus, though he has a good solution for the basic motor / bearing platform. |
So now I have a dilemma. Frogman sending the extra arm board and Bruce sending the longer grub spikes. Ahhh, so many choices, so little time. I wish all decisions were like these ones Harry .....:^) |
Pegasus
Regarding arm boards and optimal materials, it’s very interesting to watch the diverse experience in idler drive plinths. A mixture of natural and slightly lively wood layers, combined with *some* more deadened materials, like *a bit* of MDF and maybe one layer of stone seems to yield very good results . Pegasus Re: idler drives When I was curious and going through a turntable phase, any thoughts of building a plinth for a stock L75 Lenco as a project were squashed after acquiring a Jean Nantais Lenco, and having a look under the cover. JN LencoFrom my experiences, the idler design deals with the highest noise factor. I think the Lenco Swiss motor is art, but the wheel interface with the platter is not. Some go to extremes to contain resonances/vibrations. Looking at the pic in that link - JN found that huge voids are necessary under the armboards and motor areas; wide open to the bottom to help with containing/absorbing the resonances/vibrations. I/3 ? of the plinth is empty (air) - but it still weighs 100 lbs. |
Regarding arm boards and optimal materials, it's very interesting to watch the diverse experience in idler drive plinths. A mixture of natural and slightly lively wood layers, combined with *some* more deadened materials, like *a bit* of MDF and maybe one layer of stone seems to yield very good results. Pure MDF not, neither Corian, synthetic stones, marble or metal is desirable. I think a considerable part of this experience should be considered when thinking about armboards. Solid wood and *maybe* a bit of acryl or alu smewhere should work well too.
Personally I'd seek other materials than overdamped polymers like Sorbothane - it's sounds like s*** as a platter mat, and it's audible wherever one uses it. Even natural rubber feet on speakers (or under analogue decks) sound IME sluggish. It's easy to overdamp surfaces and overtighten connections (not only because of eg. making cracks in the ET structure :-). Both result in kind of a deadened, "negative feedback" kind of unnatural sound.
Solid maple? A friend uses solid oak to very good effect for the adanalog arm.
For ET arms maybe solid sBruce is the optimal wood...?
An eminent discovery. |
Well said John. In an effort to contribute I want to give a shout out to the Medo AC0105 air pump. It is rated at 7.11 PSI so it's only suited for those of us who have not upgraded to the high pressure manifold. It is also rated for a 60 min duty cycle. That aside, I have been using this pump for about three months and twice I have forgotten to turn it off when I went go bed. It just keeps pumping along and my gauge says I'm getting about 8 PSI. It is not quiet enough to be close by the listening position and does run hot. However, in my experience, it is quieter than the famous Wisa.
I solved both issues by building a sound box with a plate fan in one end and vent in the other. The box is built from mdf and lined with carpet padding both acquired from the audiophile dept. at Home Depot. The plate fan is very quiet and purchased from Amazon.
I have about $125.00 in the whole project including the pump and a new PVC surge tank.
Anyone wanting more details, let me know. |
I guess I'm not sensitive about those terms, but I did get a bit hurt when someone, a young know-it-all, referred to me as "old school."
Experience helps. I've stepped in most of the potholes already. Some people have a long way to go to catch up with me. |
So now I have a dilemma. Frogman sending the extra arm board and Bruce sending the longer grub spikes. Ahhh, so many choices, so little time.
John, you are so right. Over the last month + I have done about four ot five tweaks to my analog front end. All directly or indirectly the result of suggestions or ideas expressed on this thread. Each such tweak resulted in a marked, repeatable improvement in my listening experience. And, the level of technical expertise possessed by the people here is amazing.
It is very rewarding. I only wish I had more to offer. Hopefully just reporting my results can be of assistance to others.
But lastly, John you must develop greater sensitivity for the elderly when you speak of how old your "antique" equipment is. :)
Cheers,
Harry (Grandpa)
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Hi Harry, I have done the tweak that frog man suggested. I used rubber grommets which gave me about a quarter to half inch extra height. Also as I believe somebody else suggested I think it isolated the armboard better. Very easy fix in my opinion. |
Well Harry,
There you have it. I wouldn't argue with freebies, but YMMV.
What a great resource this thread has been!
Cheers,
John |
Harry, got your introductory pm. Re damping between the boards:
While I agree with John in principle (I am not a fan of Sorbothane), I would, as with all this stuff, let your ears be the final judge. As I see it, because of the way that both boards would be secured tight by bolts to the metal subchassis, I don’t think that rigidity will be an issue. I do think that Sorbo may cause too much damping or you may not like its particular signature. I will include a piece of the material that I used when I made my constrained-layer- damping platforms for my rack. It is a very thin rubberized cloth material that is used in flooring installations that is very effective but not squishy like Sorbo at all. About 1/4 the thickness of the Sorbo sheets that I am familiar with and much more difficult to compress. It is easily reversible if you don’t like it. I find that there are few absolutes when it comes to tweaking, and as much as we would all like to think that our systems are "neutral", most tweaks related to resonance within and outside the system are perceived as positive or negative relative to the particular tonal signatures of our particular pieces of equipment and their cumulative effect. Experimentation with an open mind (ear) is the ticket, imo. |
Hey Harry,
I'm not sure that a piece of godawful sorbothane between armboards would be good. Some areas are meant to be rigid. Then again maybe harmonics would not be crushed by doing this with the VPI? I would check with Harry Weisfeld before doing anything like that. -Just my 2 cents.
John
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