I certainly hope so Frogman :^)
His results were fascinating but predictable, and showed when it comes to this analog vinyl hobby much can be figured out. Since its all mechanical, vibrations, resonances, electrical. There is no hokus pokus going on.
01101101 01110101 01100011 01101000 00100000 01100100 01101001 01100110 01100110 01100101 01110010 01100101 01101110 01110100 00100000 01110100 01101000 01100001 01101110 00100000 01100100 01101001 01100111 01101001 01110100 01100001 01101100 00100000 00100001 00100000
And I say the above as a career IT guy......
My understanding (without giving away his observations) is he substituted the chopstick but kept the single leaf spring and the inert lead weights.
As we know the leaf spring is like a tuning fork designed to resonate. And when used as a single, double, triple leaf spring can be matched up to a resonating cantilever, much like a musician tunes up his instrument. I am more assuming here as I was a trombone guy - and the only valve was for body fluid from my personal distillery (thank u Pagasus !) My tuning was done with my lips. So maybe Frogman, Pegasus, ....can elaborate on the tuning instrument aspect better.
As with a tuning fork - a thicker stiffer one (ET2 double/triple leaf spring) will resonate higher than a thinner one - ET2 single leaf spring)
Anyway imagine what happens to the music when you add in something that is porous and absorbs much more so than the stock I beam itself.
Quiz question:
What leaf spring would work best with a stiff cantilever from an MC cartridge ?
(Hint you want to match the cantilever up to the resonating I Beam)
As the Canadian dollar continues is crumble against the American dollar - I am now willing to bet 115 instead of 100 Canadian loonies that no professional reviewer in the history of the ET2 ever figured out the above. |
|
Chris, google isn't as good as it used to be: it hasn't brought up a chartreuse key with a dayglo (bright) label attached to the short end reading ... HOLD HERE. |
Boy.... tough crowd .... do you agree Dover ?
John47/Frogman - I always seem to have good luck fishing when the lure has a chartreuse color scheme to it.
So I am thinking of getting a chartreuse colored wrench...that is unless Dover advises differently.
Probably be easier to find it when I drop it in the carpet as well. Maybe it will fall next to the loose leaf spring I have been looking for. (Forum readers that have never owned an ET2 and not paying attention here are now heard muttering - what is a loose leaf spring ? )
Frogman - thx for the link. I am a little disappointed that PB Swiss Tools doesn't offer an Audiophile "Woodie" version made from the hardest and densest wood. A Woodie wrench would have (past tense) made a great Christmas gift match to an audio friend who recently tried his ET2 with what he calls the
"ET2 Chopstick I Beam Mod"
If he sees this I dare him to post a pic here.
Who knows ...it might make it into the Annual 2015 ET2 Audiophile W(rap) |
|
Dover, please advise what colour Allen key Ct0517 should use.
"By the way in your original post you suggest using the short end of the allen key - in fact using the long end in the cap screw, and turning the short end to turn will put less torque on the bolt." Dover |
Ct0517,
As you know the ET2 is a very tweakable arm. I run slightly higher torque settings on the 4 arc bolts and for this reason I loosen them slightly before adjusting VTA. Your analogy of car wheels is rather odd. In over 35 years of running the ET2 the arc block is still original and in pristine condition.
I did have some customers who managed to break and grind down arc blocks by over tightening and trying to adjust VTA whilst overtightened and indeed one customer who managed to break 3 cartridges mounted on their ET2 back in the day, despite adding copious amounts of mass... |
Dover
Ct0517 - when I do VTA adjustments I always loosen the 4 bolts slightly to release pressure on the arc block, and then retorque. Indeed if you loosen the bolts too much alignment goes out, but you can loosen them slightly whilst arm is mounted if you are careful. This gives new meaning to ET2 VTA On The Fly. Before I drive down the road in my car, I make sure that the rubber has been mounted properly on the rims, and that the wheels have been properly installed and torqued on the car, before it hits the road. I don't touch the bolts after that. This is no different and the reason for the analogy. Dover
By the way in your original post you suggest using the short end of the allen key - in fact using the long end in the cap screw, and turning the short end to turn will put less torque on the bolt. The wording I posted is direct from Bruce. I took "use the short end" to mean the person "holding" the short end, which is what is implied. However you took the meaning differently, and maybe others did too, so lets clear this up. Here are Bruce' instructions again and @ Dover, note the wording below "'We would not attempt this adjustment with the tonearm installed on a turntable. " Chris,
My first rule would be to use the short end of the Allen wrench as the lever for torquing any screws on the ET-2. The short lever arm will limit the applied torque.
For the two bearing blocks that mesh the pinion to the rack in the arc block we first adjust the blocks so that they are parallel to the manifold housing with a .060 -.090 gap between the bearing block and the back adjacent surfaces on the manifold housing.
The friction between the manifold housing and the arc block define the feel of the VTA mechanism lever action. We want this to offer some resistance, but not too much when a VTA adjustment is attempted. Turn the 4/40 x 3/4 bearing block screws so that some friction is encountered when adjusting VTA but not so much that the VTA mechanism locks up. We would not attempt this adjustment with the tonearm installed on a turntable.
The main failures we see with the arc blocks are:
1.The threaded insert on back surface of the arc block is cracked due to over torquing of 8-32 stainless steel button head post mounting screw.
2.The bearing blocks on either side of the arc block which support the pinion gear are over torqued which crushes the pinion into the rack and binds the mechanism, if a VTA change is attempted with over torqued bearing blocks the pinion turns and the rack does not move, stripping the teeth on the rack.
I hope the above helps
- brucet |
Merry Xmas to all.
Richard - congrats on the new ET2. Are you going to mass this year ?
Ct0517 - when I do VTA adjustments I always loosen the 4 bolts slightly to release pressure on the arc block, and then retorque. Indeed if you loosen the bolts too much alignment goes out, but you can loosen them slightly whilst arm is mounted if you are careful. By the way in your original post you suggest using the short end of the allen key - in fact using the long end in the cap screw, and turning the short end to turn will put less torque on the bolt. |
Slaw - I've noticed lately that, the ARC/POST has an issue.
(This is an ongoing issue with the ET design)
If, you can look at your ET from dirrectlly behind. you'll notice the the arc block / post doesn't "square-up". Both mine appear fine. Mine also have a very tight tolerance. In fact Bruce highlights this tolerance level in the manual. Have you turned any of the four horizontal VTA block bolts with the arm mounted. This may cause the condition you describe. You have definitely thrown out your VTA block tracking if you have turned the VTA bolts with the arm mounted. Note: The ET2 manual is the original one with no updates that I am aware of. It contains a lot of good info but is in need of an update . For example. Page 26 VTA/SRA mechanism. It discusses that the VTA/SRA mechanism firmness is set at the factory. It discusses how to change the firmness level. A qualifier needs to be added to that section of the manual that adjustments made to the VTA block bolts should be done off table only. This was confirmed with Bruce and is discussed here in the Nov. 11, 2014 post yellow sticky. Retorquing ET2 VTA Block Bolts I know that some owners have actually turned these VTA block horizontal bolts to help line up the stylus on the straight line. A mistake for reasons mentioned above. Slaw - I recently sent my Acutex to Axel in Germany for a rebuild. (1000 hrs +++) According to him, the stock diamond is an elliptical. An upgrade, which I chose, is the Shibata diamond. The word from Audiogon'r Nandric is that Axle is very busy these days. I hope you get your 420 str back soon and look forward to any impressions. Am curious if it gains in the musicality area but looses some of its groove/boogie factor .... |
Hello!!!
Coming out of my audio shell....
I've noticed lately that, the ARC/POST has an issue.
(This is an ongoing issue with the ET design)
If, you can look at your ET from dirrectlly behind. you'll notice the the arc block / post doesn't "square-up".
This is a disappointment! Bruce, (if you're) listening, you/I would appreciate a (CNC) type of mounting here.
This is where some of us, (experienced users) will have an issue.!
Slaw, out........ |
Hi Everyone. I hope that your Christmas is filled with music, family and laughter.
It came early for me. Another ET2 and a Jethro Tull concert.
Perfect! |
Hello People: I recently sent my Acutex to Axel in Germany for a rebuild. (1000 hrs +++)
According to him, the stock diamond is an elliptical. An upgrade, which I chose, is the Shibata diamond.
I'll, at some point, update on the difference.
It most likely will be quite a while. I'm having too much fun right now with me Dyna D3! |
A safe healthy holiday season to you and ours; and all who read this. And thank you for what is, without a doubt, one of the most interesting, educational, and (by Audiogon standards) safe healthy threads; not to mention fun which is something we sometimes forget about in our search for audio perfection. ****For me I am thinking the man in black is going to look good on my mag wand..... **** Definitely! But only the mag. The livelier aluminum should be reserved for the spouse; or..... http://m.youtube.com/?#/watch?v=0M3uR24_V10A voice as mellifluous as the sound of a well-setup ET2. Speaking of audio, setup geometry and the Mona Lisa.... http://geometricinspired.com/da-vincis-mona-lisa/He may have used the Golden Ratio in his wire designs, but I still prefer the AudioNote to the Cardas.... |
The 2014 ET 2 Year End Audiophile W(rap) Some of the past pics and ideas from this thread to give others information sharing, and maybe get creative juices going for those that are in gear mode, or looking to do something different. Please feel free to post your ideas and pics to give the others ideas. You can also send me a link or pic at bcpguy (at) bell (dot) net and I can post it for you. To start it off. ***************************** Mona Lisa of ET 2 tonearm wiring ***************************** imo - This is Tonearm Wire Art and belongs in an Audiophile Art gallery Wire Art 1 Wire Art 2 Note also the special audiophile wrap on the armtube. Happy face loop putting the weight of the wires downward where it leaves the armtube. Minimal and consistent resistance across the record. For me and my anal attitude toward Mr. Wires (I am still searching for a wireless solution). If I am using a flat plinth surface, this is the route I would take. Serious passion lives here. :^) ***************** Go Your Own Way ***************** In the spirit of Fleetwood Mac's "Go Your Own Way" The first time I saw this ET2 setup my lower jaw dropped. Total and absolute Individualization, customization, and imagination to an extreme level. Serious passion lives here. :^) ************************ The Aspiring ET 2 Comedian ************************ If your current situation does not provide you with the ability to make people sing and dance, then how about making them laugh....(Sharing knowledge and information from direct experiences works well too.) *************** Swiss Army Knife *************** Many have called the ET 2, a swiss army knife version of a tonearm on the LP, with its Zero tracking error, and the multitude of adjustments to match up to the record. Its the Slave, the record is the Master. I think everyone still remembers this one ? Micrometer ET2Serious passion lives here. :^) From my own direct experiences, any new owners trying to make this level of precision work; better have their Music Room, Speakers and Amp/s combination already dialed in ahead of time. There is no place to hide here. Unlike my pivot arms which when set up at even 90%, can sound decent. This is an all or nothing scenario. You will know if it is out. ****************** The Freedom Fighter ****************** In the spirit of the P40. The Freedom FighterIn this example - a rare eye condition necessitates the use of special glasses. The left eye (in the pic) wants to go straight. The right eye (can't be seen) wants to keep turning right. The glasses correct this condition. **************** ET 2 on a Pedestal **************** The one that started all this insanity and was part of the inspiration to start this thread. The ET2 on a Pedestal In this case a 20 lb hunk of brass cut from a brass billet. I wish some of my financial investments were doing as well as this hunk of brass is in regards to market prices ! The ET 2 loves to be on its own pedestal. The reason ? The wires coming off the ET 2 drop naturally and can be put into a happy face loop. Keep the wires happy and you will keep your ET 2 happy; has been my experience anyways. The pedestal is a natural for wire management. And last but not least..... ************************** Audiophile ET2 Armtube Wrap ************************** The wrap seen here works best from December 15 to about January 2rd. Guaranteed to make those holiday tunes more enjoyable for you and your guests. Once outside of the holiday period, with some imagination, the wrap can be replaced with images of your favorite music makers, maybe your favorite pet or .........how about your spouse ? Can you Imagine her (or him) riding the grooves to your favorite music ? Guaranteed to put a smile on the faces of your guests. For me I am thinking the man in black is going to look good on my mag wand..... And let's not forget the additional benefit for Audiophiles ..... the visual placebo effect is engaged if images are from dead classical composers, and / or jazz musicians. :^) That's a w(rap)........ Wishing you and yours a safe healthy holiday season. Cheers |
Funny about your lab pup. Our Artie loves to try and catch the shower of leaves when using my beast of a leaf blower (Husqvarna; again).
Loves it second only to sitting still with an expression of total contentment when I blow dry him with it. What a life ! Yup .... 13 to 15 years of a good dogs life, with a family that cares. This is starting to look really good to me .... Audiophile (w)rap lol - - - |
Too funny!
****I can't stand disposable items ...which is what our society has become. ****
An endless argument (not really) between my wife and I. I am always lobbying to hang unto things like our old Sub-Zero which, even after a couple of major surgeries cools and freezes like no other. Funny about your lab pup. Our Artie loves to try and catch the shower of leaves when using my beast of a leaf blower (Husqvarna; again). Loves it second only to sitting still with an expression of total contentment when I blow dry him with it.
Anxiously awaiting your "Audiophile (w)rap".
Yo |
yo-yo-yo wassup ?Been digging out from the past storm with a very weak snowblower. :^( We hardly got any of the white stuff that hit Buffalo a couple of weeks ago. It was seriously looking like a brown Christmas. That changed 2 days ago! Should have dealt with the symptoms of a stretched auger belt last year. Ones gets lazy with age. Bought 20 years ago my Craftsman 11 hp 31 inch snow throw can once again win the snow pissing contest after replacing a $20 auger belt. A timeless design. I am a total sucker for these kinds of things. I am surrounded by this stuff and I include my audio gear when I say this; It will all outlast me. I can't stand disposable items ...which is what our society has become. Note: Its important when having so much fun hurling snow 20 feet to avoid hitting your wife's car. The 4 month old pup can't seem to resist himself, jumping and hurling himself too; trying to catch waves the of flying snow being thrown out by this incredible man made invention. btw - This is the only time you will ever be able to find a black lap pup - in amongst all the white stuff at night. He normally needs to wear a collar flashing light so we can find him in the dark. In the spirit of this thread, some ET2 passion shots to warm things up a bit ? coming up |
****An audiophile wrap ? Hmm this gives me an idea ...... more in a bit :^)****
Yo, yo, yo! Wassup? |
The big guy dancing in that "Its all about the bass" video cracks me up. He stole all my dance moves. There is more mass moving side to side with him though. Like an ET2 without the decoupled counterweight. Frogman - I think you can do a lot with the original aluminum armtube and play heavy MC on it as well with tweaking. Your post supports this. But then you have also wrapped your aluminum armtube. A pic of it is attached earlier in this thread. An audiophile wrap ? Hmm this gives me an idea ...... more in a bit :^) It is not the same imo with my 2.5 with heavy Mag wand which I use with Richard's aluminum gooseneck. My experience puts this combo solidly over the fence onto the other side with Low Compliance MC cartridges only. The combo didn't work as well with the high compliance Acutex 420 str cartridge. That same 420 that had excellent drive and rhythm with the CF armtube and regular CF gooseneck joint became cruder and harsher sounding from what I remember. Its been quite a while. It didn't last long on there. The Acutex 420 high compliance MM is still on my 2.0 and aluminum armtube in my other room. That's also the combo Bruce liked best in his review of the 420 cartridge posted here earlier in the thread. Good lord its been a little over two years since that post now. 8^o |
Chris, re high compliance carts with the ET2. I agree with you that it can be used successfully with them and have done so for as long as I have owned the arm; which is almost as long as it has existed. I remember more than one comment by "reviewers" stating that the arm performed best with low compliance carts; this, even before the mag wand was even available. Then there was the review which praised the Monster AG2000 cartridge (low compliance) as THE cartridge for the arm; and idea that I heard repeated many times in NYC audiophile circles. It is, in fact, an exceptionally good combination (I own it) even with the regular aluminium wand and I think that this contributed to that mistaken idea taking hold.
And it IS all about the bass. Get the bass right and things fall into place. Now, 350 millions hits! Actually, it's a pretty catchy and cute song. Too bad that a well intended (I think) message has to be combined with the typical-for-our-time crassness. "Junk in all the right places". Now, THERE'S a nice thing to point out to one's daughter! |
Hi everyone - time sure flies by when you are having fun ? This came into my email inbox today - it may or may not represent an ET2 opportunity based on the auction selling price, but it is interesting for a couple of reasons so I thought I would link it here. A base low pressure ET2 - and with a Mag wand ! You can tell it is a ET 2.0 not ET 2.5 by the end cap that overlaps the spindle. You know it is probably a base and not HP model by the original pump shown. The Good Remember the earlier post about the VTA Block / Worm Gear relationship. This one shows the bearing gap clearly from the top pic. Any bidders are however advised to verify the "rack of teeth" condition with the seller. All parts are almost all there including the brass rings meant for "leveling" only. The VTA lever appears missing. Again verify with the seller. The obvious Mag and Aluminum arm wands - sweet. The Bad That pump can be placed at the bottom of the rack - it is that quiet and cannot be heard from 5 feet away. The seller (well his partner - read on) indicates it is noisy so l think the pump needs replacing based on the ad's wording. The aspiring comedian in me found some of the ad's wording ...kind of funny. I've replaced it because my partner hates it, and has dubbed it the "user-hostile" arm. She has a point -- you have to turn the pump on (and you should have the pump muffled or in another room, because it's noisy), and the arm's a bit fiddly to cue up. "user-hostile" - there is that military weapon reference I alluded to earlier. Also Still, every cartridge and table I've tried with it (within reason, don't use a high compliance cartridge with it!) sound absolutely magnificent. Obviously not a long term owner and has not been paying attention here. The original base ET2 came out in the hey day of higher compliance MM's . I have used an ET2 with aluminum armtube very successfully with a Sonus Blue MM. 50 cms/dyne x 10 (-6). What I think might have happened here was the seller was using the higher compliance cartridges with the big FAT boy.....Mag wand. If the seller is part of the average 5000 viewing this thread appears to be getting every day - Holy Moly ! - I hope he doesn't mind us using his ad for education, knowledge sharing, and a bit of humor. I don't think he does as he does show a sense of humor himself. Next post will be a Yellow Sticky again - Proper ET2 Bass Management......(ATB) "According to Bruce" It will be my humble attempt to put Thigpen's words of wisdom from his two part ET2 manual, into "one short easy to read post" for audiophiles and music lovers. Can this be done ? Get the bass right, the rest follows.... It's all about the bass.- |
**** ET2 Thread Yellow Sticky- VTA Block Pt.Two -How to Torque the VTA Block Bolts **** This post also to be known as ; "Honey, winter is coming. Do you think we need to put new tires on the car?" Well non-ET2'ers must by now realize that you need to be a little mechanical minded with this tonearm, if a post subject is dedicated to how to torque the VTA block bolts on the ET2 ? Would you expect any less for something that is patented ? Its now confession time for ET2 owners past and present. How many of you after seeing the gap between the manifold housing the bearing block said to yourself ... Hmmm... I better close this gap, somebody left it loose and open. If you did this, you just locked your VTA. Jammed the worm gear post up against the rack of teeth as far as it will go. If you use the VTA in this manner you will strip the rack of teeth or it will not move at all if there is still tread left on the rack of teeth. VTA Block Gap and How to Torque the 4 VTA Block BoltsThe pic shows (left side) where the VTA Gap is and (right side) one of the VTA bolts being torqued. This is repeated for the other 3 VTA bolts. Takes only minutes to do. Two important tips from Bruce mentioned on the earlier VTA Yellow Sticky Part One post. 1) Use the short end of the allen key. Torque is dramatically reduced. 2) Do not make adjustments to the 4 VTA Block bolts while arm is mounted. You will throw out your alignment. All adjustments should be made off table. Also just to clarify when Bruce says .060 -.090 gap between the bearing block and the back adjacent surfaces on the manifold housing. It's in inches. The adjustment can be done by sight if you are familiar with it. A feeler gauge is shown in the picture on the right. And the gap range is a starting point as all ET2 VTA Blocks are machined individually. The key is to be even in the torquing on the 4 bolts, and to torque so there is a nice personal firm yet smooth feel and no binding to the VTA mechanism. Some of you may notice that the gap in the picture above is well below the .060 - .090 recommended range that Bruce recommends. This one is down to .20 but it still happens to track properly and true. How can this be ? I asked Bruce to confirm some observations.
Bruce - is it a fair statement that over time the rack of teeth due to friction with the post will wear down. When the firm VTA feel starts feeling loose it should be torqued down evenly a little more, off the table. If this procedure is followed you will get many many years of use out of the VTA block ?
I believe some have been just turning the VTA bolts individually without realizing the effect on the rack of teeth, resulting in uneven wear and at some point a VTA block that goes out of alignment.
Chris
Chris,
This is correct.
- thanks -
brucet So the rack of teeth "tread" wears down over a long period of time due to friction with the post worm gear. Maybe some new tires will be needed for the one in the picture soon. If you want to use a gapper like the one in the pic then can be bought cheaply from the automotive parts store. The one you need will look like the top picture in this link. GapperEach of the metal shims are called feeler gauges. Try to get one that goes up to .35. Also companies like Acklainds Grainger sells longer version feeler gauges. Pull out the two or three largest ones so they are side by side. Insert them between the VTA bearing blocks and the back surface of manifold housing. Turn bolts till snug but that you can still remove the shim. Test and feel how the VTA lever works off table. If it is firm and smooth your ET2 VTA Block is now torqued evenly and ready to be attached to the Pillar Post. |
Frogman to Slaw - BTW, I have enjoyed your music posts in the recent past. +3 I know that Slaw has a record collection that many can only dream of. A true music lover. |
Slaw, nice to see you back on this thread. Normally, I would defer to the OP for any ceremonial "Welcome back" commentary; but, since you addressed me.....
As with most things, context is everything. I don't remember the context of my comment re 18.5 psi, but I I assure you that there was no personal slight intended by my comment (geez! we're talking about air pressure after all). I would normally welcome an opportunity to clarify a comment and continue dialog, but I see no point if you are simply going to "disappear". BTW, I have enjoyed your music posts in the recent past. |
Chris, some brilliant posts recently. Thanks! And thanks for keeping one of the very best threads on the 'goN alive and relevant.
Re "time on one's hands": as Vic said in "Broken Arrow": "Ain't it cool?" |
@Slaw I kept wondering why he didn't question Ct0517's ongoing use of 19 psi? My 2.5 HP manifold is a custom build by Bruce designed for 19 psi. I run it at the psi it was designed for. Here is a real life example of a situation that may help understand what I said a few posts earlier in the Air Bearing Sticky Post. A long time ET2'er is running a base ET2 which has had a recent cleaning maintenance done. He runs it with the stock original Takatsuki pump that still produces the 3.0 needed for the base ET2 to work, but not the 3.6 PSI the pump produced when it was new. It sounds good to him. On a whim he buys a little Medo medical pump on ebay. He notices that it makes 12 psi at the pumps output, but after travelling down 15-20 feet of air line he discovers the PSI drops to 7 psi at the gauge mounted near the tonearm. The music sounds better to him so even though this Medo makes enough noise to have to isolate in another room, he keeps it in place as it is worth it to him. He has it hooked up to 20 feet of hose and in another room. He's happy. He puts the stock pump away as a backup. Now the maker of the our tonearms teaches us that if we improve the air supply the sonics will improve; but that over PSI'ing the arm can't hurt it physically as it is a robust design. Based on the above example and info, did the sound get better with the little Medo pump because; 1) The PSI at the ET2 was increased to 7 psi from 3.5 stock pump. or 2) The overall air quality delivered by the little Medo pump was better. What do you think .... 1 or 2 above ? btw If anyone here is running a system with 10-15 feet of air line, and you have a quality pump that can still produce the PSI you need with a 60 - 100 feet of air line. Buy the air line as it is cheap - coil it up like a car's coil spring to save space. You will improve your sonics but only if your pump is of a design that can deliver the PSI for the longer run. Try it and find out. From Bruce' website. --------------------------------------------------------------------------------------------------------- 3.6 PSI - 0riginal Takatsuki and ET-2 or 2.5 5.0- 7 PSI - WISA 300 air pump and ET-2 or 2.5 with high pressure manifolds >10 PSI - users with shop compressors and ET-2 or 2.5 high pressure manifolds Note, if the pressure readings are higher than those listed above, the manifold could be clogged, if the pressure readings are lower, this suggest that the pump may not be performing correctly. ---------------------------------------------------------------------------------------------------------- Slaw - you got your tonearm direct from Bruce correct ? What PSI was your HP manifold designed for ? Lets start there.... imo this is your personal reference point for your system ... |
I also happen to believe based on my compressors versus current setup from years ago, that there are advantages in a constant air psi being delivered by a quality pump versus a cycling off and on compressor which is like letting air out of a balloon slowly. I tend to agree, would you want a phono stage with a constantly changing input impedance. I wondered if anyone here has investigated the use of variable speed/variable capacity rotary air pumps to provide a balanced load and eliminate the pulsed air supply endemic in piston type pumps as used in most of the compressors mentioned in this thread ? |
Pegasus You don't get steel more elastic than with a perfectly pointed unipivot interface. Then think "it" as an elongated point and you see something like a short subminiature "string" at the end of the point - quite elastic, like a very small piece of microscopic harpsichord string. "Flatter" points like balls have much less of this, and make stiffer bearings Thanks for feedback - regards the above, this is one of the reasons I chose the Naim Aro as a second arm - it uses a radiused tip in a larger radius cup for the unipivot. |
Something has bothered me for quite a while. I'll ask the question and disappear.
A while back Frogman responded to a post I made on the subject of the regulator I am using stating that he was surprised I could hear the difference between my stated 18.5 psi and other's 19 psi.
I kept wondering why he didn't question Ct0517's ongoing use of 19 psi? Why question me at 18.5 psi and not Ct0517's 19 psi? This, to me, makes no sense.
I'll leave this to all of you.... |
an et piece that broke. In 2003 I over torqued and cracked the very important end cap. In 2003 Bruce charged me $45 for it. Back in 2003 $45 also filled the tank of a 65 litre (17 US gallon) car gas tank at 68 cents a litre (3.78 litres in a US gallon), 11 years later, Bruce still charges $45 for the end cap if you break it; but gas is now $1.25-$1.35 a litre now where I live. $45 now barely fills half that same tank. |
Thanks for the tip CT. Will call Bruce.
Dealer is very well known in this community. He makes calls every week.
Bruce no longer has vmail; it just rings or someone picks up.
I have purchased items from Bruce directly, like the carbon fiber arm, new weights, wand, and air pressure gauge. I really working with Bruce, but wasn't sure why this long shipping delay has occurred.
This go around I wanted dealer to accurately setup the touchy Sota/et2, and it required an et piece that broke. |
Thanks for the tip CT. Will call Bruce.
Dealer is very well known in this community. He makes calls every week.
Bruce no longer has vmail; it just rings or someone picks up.
I have purchased items from Bruce directly, like the carbon fiber arm, new weights, wand, and air pressure gauge. I really working with Bruce, but wasn't sure why this long shipping delay has occurred.
This go around I wanted dealer to accurately setup the touchy Sota/et2, and it required an et piece that broke. |
*** YELLOW STICKY FOR ET2 THREAD MARK - VTA *** I want to thank the recent private exchanges with Banquo363 for inspiring this post to be known hereafter as the Brothel Post :^) Why does the action of my ET2 VTA, resemble me Coming Out Of A Brothel at 2:00 am ? Has your ET2 VTA lost its MOJO ? The post is broken down into three parts. PART ONE - Recognizing the problem. . PART TWO - How does this problem come about PART THREE - Solution/Fixes I learned quite a bit during the preparation of this post which took about 6 full coffee sessions to prepare. It started out as a big dump of info which was slowly reduced to what is here. If any of this post helps even one ET2'er it will have been worth it to me. So Grab a Coffee/Tea or depending on your time zone - a drink ? ------------------------------------------------------------------------------------------------------- PART ONE - Recognizing the problem ***Note:The pictures in this thread are anonymous, real and have not been doctored*** The repeated message on this thread has been one of not torquing the ET2 bolts too rigid, most recently by Pegasus and yet once again by Frogman who I believe first mentioned it. I also endorse this. I have learned the hard way about too much torquing and am very "aware" whenever I torque a ET2 bolt. As promised lets get right to the dirty little secret. Does the action of your ET2 VTA resemble you spending too much time at the brothel ? Disclaimer/warning - the pics you are about to see show very real ET2 abuse. View at your own discretion. The Dirty Little SecretThe pic has been oriented "horizontally" to keep with the theme of the post. Plus it highlights the detail better - don't you think ? In the picture can be seen, imo, some of the genius of Bruce Thigpen. I don't know about you but when I look at this picture I am a little stunned with awe. It is SO out of the box thinking. Well behold the secret behind the patented VTA ET2 mechanism. Kind of looks to me like something designed to work on the Mars Lunar project ? For ET2'ers that know about this ET2 VTA, what is seen in this picture is plain and simply, "A relationship gone very very bad between Mrs. VTA Block and Mr. Post (aka) "Mr. Worm Gear." :^) Are the brothel similarities becoming a little clearer ? When you ride a train you assume that the tracks the train runs on are in good order and will get you where you're going without incident. How many here were/are aware that the tracked/ridged worm gear Stainless Steel horizontal post, rides on similar tracks/ridges inside the actual VTA block's RACK OF TEETH like a train? They need to be "in the groove" with one another. Notice in the pic how the "RACK OF TEETH" are wore out. See the bald spots? How do you expect the worm gear to track that properly? This particular one was tightened down so tight that the VTA block teeth material was imbedded onto the SS post itself and the VTA block was stressed to the point of having a chunk taken out of it. You don't believe me? Here have a look... again at your discretionThe picture is a result of uneven VTA bolt torquing and locking down "rigidly" the VTA mechanism. An extreme case of way too much torquing.What good is a patented VTA system unique among tonearms if the ET2 has lost its VTA MOJO ? The good thing is it doesn't have to end up like this. Hopefully this post sheds some light and will prevent this from happening. We've seen the problem. Can it be fixed and avoided altogether? To find the answer imo, we need to look at ourselves and go back into the past a little. After all they say the best way to see the future ...is to study the past.... -------------------------------------------------------------------------------------------------------------- PART TWO - How does this problem come about. Reheat Coffee/Tea ? I like my Black Coffee Piping hot. In the beginning....:^) When we brought the ET2 home its VTA block was attached to the manifold housing already; with the four bolts torqued CORRECTLY from the factory if it was new. Now as a NEW owner of this tonearm (whether it is NEW or USED) once we got the base plate mounted and the Pillar Post on, I remember just attaching the arm without much other thought and the leveling process starts in earnest - 100 % of the effort went into leveling it. The excitement of getting it up and running, playing my records while the tonearm floated on air is just too great a feeling of "Giddy" to get over. Remember the thought of visiting a brothel for the first time ? Was it the same feeling of Giddy ? If it is, you are really old, like me. Now I just want to reiterate, that you can't be blamed for mounting it right away on the Post Pillar. I mean this tonearm in person doesn't look like anything else you have ever owned. Some friends that have seen it in person think its scary looking; imagine that. They have told me they find it intimidating, and say it looks like it belongs in the military as a weapon....seriously. If Bruce wasn't based in Florida you may also think it came from Switzerland. Well what if you buy a Swiss watch; how do you tell if all is good ? I'm sure Pegasus can tell us much much better than I can. I can only think to ask a watch pro to look under the cover, is one way.... The same needs to be done here. Look under the cover. More on this in a bit. First a short true story. Born and raised in Toronto if you research or talk to people, it is known worldwide as a nice, clean, cosmopolitan but conservative city. Some have called Toronto a smaller version New York run by the Swiss. Former Mayor notwithstanding. Now there was a time however, and unfortunately I was only 10,11, 12 ? at the time, that you could walk downtown Yonge Street, and you would see plenty of doors cracked open just enough showing the internals of brothels inside with scantily clad women sprawled across couches waiting for customers. I remember finding it odd at the time that so many of the guys they spoke to were called "John". What a coincidence I thought. I can still see them today ! No not the John's.... the scantily clad women ! Its like your old playboy, hustler and other such magazines.The women never age.... Now the really unfortunate part is that by the time I was old enough to enter within these doors - the crackdown had occurred and all was wiped clean... :^( ok - BACK ON the VTA TRACK ............ If you are a long time ET2 Owner or a New Owner that just brought home a USED ET2. New Owner Used ET2 - Don't mount the VTA Block/Manifold assembly on the post Pillar just yet. More Patience is required. You need to have a look at the VTA block's internals and assess them first. You see along with the ET2, you also happened to pick up some baggage called the relationship between Mrs. VTA block and Mr. Worm Gear" that we just saw a picture of above. If you intend to use the VTA then you need to determine if this relationship is a happy one or not. The one in the pic above was obviously NOT. Existing owners or if your ET2 is already assembled and you are having issues with the VTA. Remove your cartridge and lead weights. Remove the Main arm assembly from the Pillar Post. Undo the four bolts that hold the VTA Block in Place and pull out the VTA Block that contains the Post assembly - What do you see inside ? Have a look at the VTA treads (RACK OF TEETH) inside. Do they look clean with no tread fragments on the worm gear. And do the teeth/tracks/ridges look even, sharp and well defined. If Yes - this is an indicator of proper torquing. The VTA bolts are torqued at the factory. But we all know we get curious and all of us - "ALL" - have re torqued the VTA block bolts - each one,probably different than the other three. The ridges/treads get worn unevenly when u do this. The VTA Block mechanism tells a very important story in a used purchase. The history of your arm. Was it owned by a VTA Virgin or a VTA Whore ? IF YOU HAVE AT ANY TIME RE-TORQUED ANY VTA BLOCK BOLT WITH THE TONEARM MOUNTED ON THE TABLE- YOU HAVE THROWN OUT YOUR ALIGNMENT. Torquing and adjustment of the VTA block needs to be done - "OFF THE TABLE" Sorry for yelling on this last point - but it is very important. ------------------------------------------------------------------------------------------------------------------------------ PART THREE - Solution/Fixes If you indeed discover that your ET2 looks sort of like the one in the pic, All is not lost. You see unlike real life where pills are needed if you happen to lose control of your tool, here in Vinyl land you can actually have a new VTA block sent to you so all is good again. You can again have the joy of the patented ET2 VTA Brothel and enjoy your music. FIRST OPTION - GET A NEW VTA Block Send your Manifold housing, VTA Block and Pillar Post to Bruce. He will machine a new VTA Block for you. This will result in restored operation, and now with an owner that has real knowledge based on past experience. I would also recommend anyone who is upgrading the Manifold to HP - ask Bruce to check your VTA block assembly as well so he can assess if he needs to replace it. Each VTA block is unique (one of kind) as far as how it joins to the manifold assembly. IMO the price shown on Bruce' site for the parts and machining that contains a new VTA block and SS Horizontal Post gear inside is an example of an manufacturer who doesn't gouge audiophiles. Now a note : If you are buying used ask the seller to check the VTA Block condition for you. Otherwise assume you may need to purchase another VTA block if you want to use the VTA. SECOND OPTION - RESTORE YOUR VTA BLOCK TO FACTORY SETTINGS If your VTA Block is still in Good Shape but you feel you have "messed with it" and want to set it up to the factory settings here are the instructions direct from Bruce Thigpen. From Bruce: (word for word) My first rule would be to use the short end of the Allen wrench as the lever for torquing any screws on the ET-2. The short lever arm will limit the applied torque. For the two bearing blocks that mesh the pinion to the rack in the arc block we first adjust the blocks so that they are parallel to the manifold housing with a .060 -.090 gap between the bearing block and the back adjacent surfaces on the manifold housing. The friction between the manifold housing and the arc block define the feel of the VTA mechanism lever action. We want this to offer some resistance, but not too much when a VTA adjustment is attempted. Turn the 4/40 x 3/4 bearing block screws so that some friction is encountered when adjusting VTA but not so much that the VTA mechanism locks up. We would not attempt this adjustment with the tonearm installed on a turntable. The main failures we see with the arc blocks are: 1.The threaded insert on back surface of the arc block is cracked due to over torquing of 8-32 stainless steel button head post mounting screw. 2.The bearing blocks on either side of the arc block which support the pinion gear are over torqued which crushes the pinion into the rack and binds the mechanism, if a VTA change is attempted with over torqued bearing blocks the pinion turns and the rack does not move, stripping the teeth on the rack. |
Hi Stu - welcome to the thread. This has continued for 2 months. With total respect to the relationship with your dealer; based on 2 months of waiting I personally would be inclined to demand better status information from the dealer; in order to satisfy you they would in turn need to demand better status info from ET. An alternative is to contact Bruce directly. brucet(at)eminent-tech(dot)com Let us know how you make out. Cheers Chris |
***** ET2 THREAD - BEARING STIFFNESS STICKY DISCUSSION ******* Just so this info does not get lost here. :^) Pegasus
Regarding the pressure compensation, it might help to use the analogy of a stiff power supply (air supply & reserve connected to manifold) with a few local supplies (local pressure zones around air capillary openings to the bearing) coupled with high series resistance (capillaries). As current (air flow) drops on one of the sub-supplies, the voltage (air pressure) rises - kind of a passive feedback!
Regarding the usually alluded inherent "stiffness" of mechanical bearings including unipivots, it's worth to consider the following thought:
No material is stiff, everything is more or less elastic. (With some unique properties subsummized in the poetic word "character", importantly damping, and including speed of transmission). Reduce pressure area, and elasticity increases. This affects resonance frequency inherent in any elasticity / mass combo. *Point* coupling as in a unipivot or a spike point, looked at on an "atomic level", is in no way making the coupling stiff, it's the opposite. The surfaces meet in kind of a balanced force & elasticity state, a bit like a jelly ball swimming in water, to put it to the extreme. You don't get steel more elastic than with a perfectly pointed unipivot interface. Then think "it" as an elongated point and you see something like a short subminiature "string" at the end of the point - quite elastic, like a very small piece of microscopic harpsichord string. "Flatter" points like balls have much less of this, and make stiffer bearings - that depend more on extremely complex polishing processes. Some arms use the tip of a roller pen, quite clever!
The whole "argument" (rather a mythical marketing image?) of the "mechanical diode" is moot. Point coupling shurely does "something" (as everything we do does) but shurely it is not "stiff coupling" or magic diode processes. It might eliminate eg. multi-point rattling by a multitude of low pressure indefinite points, eliminating noises of "buzzing paper on a comb"-effects, tingling in metal-to-metal sonority.
And... air bearings are at the total other end of the scale!
.
That's what Bruce tells us since a long time. Yes for a long time page 3 of the ET2 manual. The large surface of the air bearing uses some of the tightest tolerances in tonearm manufacturing today, and is much more rigid at audio frequencies than metal bearings" what imagery and a way of expressing things clearly. a bit like a jelly ball swimming in water, to put it to the extreme. :^) Now regarding this statement ....... As current (air flow) drops on one of the sub-supplies, the voltage (air pressure) rises - kind of a passive feedback! An observation. When I had my ET 2.0 HP and and ET 2.5 HP both on the same table I switched their air hoses back and forth. With the supply source remaining at a constant 19 PSI, it was interesting to watch the PSI gauge go up by a few PSI when hooked up to the ET 2.0 (into the 20's) and likewise to watch the gauge go back down by a few PSI to 19 with the larger lunged 2.5. Audiogon'r Ketchup has presented graphs here showing similar information. Relevant info from the Oct 29 Post Sticky. CT0517
If we use my ET 2.5 as an example that you set up specifically for 19 psi which is your optimum design setting for your tonearm. A continuous 19 psi air flow is sent in. Can we assume the spindle uses all 19 psi to work optimally (or is it a percentage of this amount)
Bruce
The manifold is optimized for the design pressure, the pressure at the surface of the spindle is a percentage of the inlet measurement, this is by design. The ET2 uses roughly half of the air to allow the spindle to work properly ? The supporting force is the surface area of the bearing times the pressure at the surface of the bearing
ME
So allowing air to escape around the edges of the manifold as more is pumped in ? is this a captured air bearing system ?
Bruce
Yes it is captured. |
Hi,
First time poster in this area.
Question
Anyone experiencing delays receiving arm parts from ET for their ET arms?
I have had my Sota /ET2 at The Analog Room for over 2 months. Requires a part from ET. Brian at Analog keeps calling ET and told part will arrive next week. This has continued for 2 months.
Stu |
Pegasus
Sorry didn't answer your question.
Air stream grounded to the house wiring earth.
Cheers |
Pegasus
Yes air supply is grounded by earthing the brass threaded part of the pressure gauge that touches the air stream. I have tried this earthing remote from the arm and close to the arm. Close is best in my setup.
Theory is that the air builds static as it flows thru the tube.
A second test, recently repeated was to place a large ferrite bead over the air tube close to the arm. This caused a dramatic negative change.
Go figure.
Cheers |
A question to all:
Does anyone have tried grounding the air supply's static charge?
I think Richard mentioned that he connected the brass of the pressure gauge to ground (which ground, where?).
Has anybody else tried it?
There are - expensive - antistatic "hoses" available. Would be interesting to try, maybe even only on the short distance between the last air tank (preferably antistatic & grounded too) and the arm.
Other grounding ideas? Like putting a copper grid into the air tank and potting the grounding wire in hot glue?
BTW my simple air tank is a 20 gallon fuel "canister" (unused :-) with a long and a short aquarium tube entering the cover of the tank reaching the top and the bottom), the whole sealed by hot glue and padded with acrylic wool. Very simple , cheap and working well. |
Hi Dover, thanks for your clarifying comments!
Regarding the pressure compensation, it might help to use the analogy of a stiff power supply (air supply & reserve connected to manifold) with a few local supplies (local pressure zones around air capillary openings to the bearing) coupled with high series resistance (capillaries). As current (air flow) drops on one of the sub-supplies, the voltage (air pressure) rises - kind of a passive feedback!
Regarding the usually alluded inherent "stiffness" of mechanical bearings including unipivots, it's worth to consider the following thought:
No material is stiff, everything is more or less elastic. (With some unique properties subsummized in the poetic word "character", importantly damping, and including speed of transmission). Reduce pressure area, and elasticity increases. This affects resonance frequency inherent in any elasticity / mass combo. *Point* coupling as in a unipivot or a spike point, looked at on an "atomic level", is in no way making the coupling stiff, it's the opposite. The surfaces meet in kind of a balanced force & elasticity state, a bit like a jelly ball swimming in water, to put it to the extreme. You don't get steel more elastic than with a perfectly pointed unipivot interface. Then think "it" as an elongated point and you see something like a short subminiature "string" at the end of the point - quite elastic, like a very small piece of microscopic harpsichord string. "Flatter" points like balls have much less of this, and make stiffer bearings - that depend more on extremely complex polishing processes. Some arms use the tip of a roller pen, quite clever!
The whole "argument" (rather a mythical marketing image?) of the "mechanical diode" is moot. Point coupling shurely does "something" (as everything we do does) but shurely it is not "stiff coupling" or magic diode processes. It might eliminate eg. multi-point rattling by a multitude of low pressure indefinite points, eliminating noises of "buzzing paper on a comb"-effects, tingling in metal-to-metal sonority.
And... air bearings are at the total other end of the scale!
That's what Bruce tells us since a long time.
|
Precisely! And, of course, once that task is done the bearing tube must be inserted into the manifold housing; hopefully, of the high-pressure variety. As always, a high-pressure manifold results in more explosive dynamics and creamier highs :-) |
10-29-14: Ct0517
*** YELLOW STICKY FOR ET2 THREAD MARK - AIR SUPPLY *** I had a quick read of your post. A few comments to clarify some misconceptions : In an aerostatic compensated air bearing as used in the ET the bearing stiffness is a function of Bearing surface area Air Gap Pressure Compensation Changes to any of these parameters will alter the "stiffness". The air gap provides a restriction - on one side you have high air pressure and the other side is lower ( atmosphere ). Air will attempt to flow from the high to low pressure - the escaping air creates the air bearing. Compensation is where you have a second restrictor between the air supply and air gap (bearing) - in this case this is the capillaries. The function of the capillaries is to 1. Distribute the air over the bearing surface in an optimum manner to get a stable air bearing. 2. Restrict the air flow to the bearing. By restricting the air flow to the air bearing a reserve is created in the manifold. For example if a load on the bearing reduces the air gap at the bearing, flow is reduced. The reserve pressure that had been held back by the capillaries now allows for increased pressure in the gap, creating a restoring force that gives the air bearing stiffness. As a general rule when compensation is used the pressure in the bearing is about 50% of the supply pressure. Bruces comments regards to the quality of air and flow reflect that compensation has a greater impact on bearing stiffness than pressure. Any restriction or damage to the capillaries or indeed scratches on the bearing surface could compromise the bearing stiffness to a significant degree. Hence your comments about maintenance are very pertinent. The Air Bearing Spindle psi requirements are less than the manifold as only a portion of this air is required for it to float properly. Approximately 50%. That means on a base ET2 only 1.5 psi ! - if your manifold is restored and functional.
The "old" air escapes as per Bruce' design out the sides of the manifold. Not really. As explained above a higher pressure is required in the manifold to provide a reserve air pressure using compensation. A leaky manifold would not be helpful. In my experience putting too much pressure through the ET2 pushes so much air out of the air gap between the spindle and manifold bushing the arm cannot reach the end of the record. At some point the rubber seals might leak but this has not been apparent. Regarding bearing stiffness. The main advantage of an air bearing compared to ball race or roller bearings as used in most tonearms is twofold - 1. Virtually no friction in the air bearing. In rolling bearings, the static coefficient of friction is higher than the dynamic coefficient of friction. In other words it takes more force to initiate motion than it does to maintain motion. In air bearings the static and dynamic coefficient of friction are the same. So the air bearing has a quicker response to changes required from the cartridge tracking. 2. Surface irregularities in the roller bearing surfaces mean that the rotational tracking is uneven compared to an air bearing. Now in terms of conventional pivoted arms, most have roller bearings for both horizontal and vertical motion. Some "knife edge" tonearms such as the old SME's have knife edges for vertical motion, but still have roller bearings in the arm pillar for horizontal motion. True unipivot tonearms have a simple point contact for both horizontal and vertical motion, so they are much closer to an air bearing than they are to a conventional gimbal arm using roller bearings. Because the unipivot has a point load, "bearing stiffness" is not an issue. Coming back the ET some contributors have commented that with increased pressure the bearing tube arm is harder to pull out of kilter( and hence the comment the bearing is stiffer ). What actually happens is if you pull the air bearing tube perpendicular to the bearing you are closing the air gap on one side. The escaping air ( from high pressure manifold through the bearing to atmosphere ) will try to find the path of least resistance - which in this case will be the bigger gap. Basically the air bearing will collapse. Increasing the pressure will help. |
I volunteer to check and make sure those capillaries are not clogged Frogman your enthusiasm is commendable ! Will the technique used to unclog the capillaries, be the same technique you use to remove dimples from speaker cone caps :^) |
I volunteer to check and make sure those capillaries are not clogged :-) |
The draft brothel post is complete ! Due to the sensitivity of the subject it has passed to Dorothy Click on me Darling for proofing. ☺️ |
|
project time management reporting
the previous post took another 40 mins.
First 20 mins to think it up, type it, push submit (all while being distracted by a puppy that seems to want to chew my leg leg off if he doesn't get 100 % attention)
another 20 mins for the system to return a successful post message. maybe some system maintenance ? maybe a little bit of audiophile exaggeration. |
I haven't felt this much pressure for a post since I stopped reporting to a boss (wife not included)
you guys prove once again that sex sells well even if in theory only. Now to come up with something that is pertinent, force us to look at ourselves, chuckle a bit, maybe destroy another audiophile inspired myth along the way ......and do it in a way that doesn't give cause for audiogon gods to delete it. Is such a post possible ? |
Chris.
Sometimes these posts can be unintentionally blunt.
re the time thing. I meant that you always seem to be prepared to spend your time researching and sharing your extensive knowledge on the ET arms. I personally have learnt much from your input, which is most appreciated.
I look forward to the brothel post!
cheers |
