Frogman - I discovered the benefits of simply mulching the leaves with my riding mower. Frogman, being the accomplished musician you are, I am having a hard time visualizing you on the back of a John Deere. this is most likely due to my own biases/prejudices. Do you wear audiophile approved ear plugs ? I highly recommend these ones. these ones - click meThese are easy to insert in any size ear canal and they work well. Not affiliated with this manufacturer. Frogman - The instrument will sound (and certainly feel to the player) more tonally coherent and with a more "right" timbre (which will affect even the perceived intonation (!)) if all the springs (upwards of twenty) have the same or similar tension. Is getting all springs with similar tension a routine task... and do some manufacturers of an instrument like the Saxophone make this easier to do than others ? Curious.. Speaking of biases. Two of my uncles played the different saxes, clarinet and flute. One of them happened to also be the music teacher at my middle school. In Grade 6 or 7 ?, I got handed this instrument by him with a bunch of piping. I was told to go learn it as the first performance was in 4 weeks for the band. At the time I remember thinking, this thing sure wasn't as cool as the trumpet, sax, or drums. It was the trombone. So I learned everything about the Bass Clef with it. Little did I know that the years that followed playing it, would influence my biases toward music from that point forward, still to today. I tend to put a bias on bass, whether live, amplified or not, and when I listen at home to full range material, I am therefore of the opinion that if you can get the bass right in a room, the rest will fall into place. More to follow on bass management... I need to go rake up some leaves. |
I remember this vividly, my mother saying to my Uncle Music Teacher while shaking her head. ...
"why in the world would you allow him to have an instrument that requires him to empty out his spit on my clean hardwood floors when he plays the instrument at home"
The floors in the school music room were disgusting. When you arrived for class you grabbed one of the mouthpieces that were in a small plastic tub sitting in some clear liquid. God only knows what that liquid was now thinking about it. The good ole days ? We survived. Now everyone is paranoid about everything. Different world not so long ago.
Uncle Music Teacher in response to my mom "should I have given him the drums ?"
Mom shakes her head..again. |
Yes frogman & CT0517 on a John Deere, what nice illustration of Americana seen the other way :-) It shurely tunes bass sensitivity, although only in a limited interval range...
Regarding "spit", isn't what most lay people (ie. the non-blowing family members too) think it is. It's mainly distilled vapour from the lungs, with maybe a bit of sulfur molecules here and nitrogen mol. there. But not much spit, I think. At least not anymore after one played two or three years.
I call my baritone sax my personal distillery. But the bowed neck (?) of a bass clarinet works already nicely as such.
Regarding trombone: This is a really great instrument! (And - ha! Ray Anderson will play november 11 in our concert program! :-) The instrument is extremely powerful in a seductive way, a lot of colours and expressive. Must be fun to play with this huge tool-box.
It's funny you mention this aspect, of first getting the fundament right, the rest then falling in place: If I'm asked about what defines the quality of a well set up ET2 (or even more a ET2.5) it is the "full-range" sound from the *lows* up, surrounded by a lot of air in the bass (first): Bass ambience. Yes, it's also sublime upper ranges, but it starts with a lucid, airy bass range with a high resolution of bass timbre & pitch.
It sounds "correct" by itself while not sounding tight-assed NFB correct. |
Not sure if this has been brought before.
I read a post on Audio Asylum about the manifold mount and how flimsy it is. The guy found the right height and then built a new mount out of ebony. I simply used a piece of wood and wedged it under the manifold. This made a huge change in the soundstage and overall quality of the system.
Tim |
@flemke: I agree! These are gradually more consequent and less reversible ways of what my cardboard wedges underneath the manifold/bearing do.
The wood option might create a more stiff but more vibration conducting, but less absorbing pathway than cardboard.
I might try a hardwood wedge someday. I like tweaks to be as reversible, low mass and "elegant" (not necessary in the visual aspect ;-) as possible. |
Chris, yes!, ear protection mufflers over ear plugs. May not be audiophile approved, but effective. Actually, my tractor is a Husqvarna GT48XLS. Love the thing. I suppose that after so much time worrying about the micro level of woodwind spring tension and tonearm resonances, I find the visceral experience of dirt, gasoline fumes and engaging that rear-wheel-differential a welcome change of pace :-)
In answer to your question: it is rare the professional grade woodwind instrument that does not require fairly extensive "set-up" even when brand new; including spring tension. Some manufacturers are more careful about releasing instruments in good playing condition than others. As audiophiles know very well, there is good and then there is GOOD when it comes to setup; a new instrument will inevitably require a visit or two to a first-rate technician. I have actually learned to do quite a bit of set-up work myself because, frankly, it's almost impossible to pay someone enough to do the kind of really fine adjustments that make an instrument feel mechanically "one's own".
Your comments about bass-management are spot-on. I completely agree with you about the importance of getting the bass right and there is, likewise, an expression among musicians that "everything starts from the bass up". IOW, get the tuning and balance of the bass instruments correct and everything else is much more likely to fall into place musically. The best orchestras (like the best stereos) have bass sections that play with the same clarity of timbre and litheness of the upper instruments, and produce sounds that are not simply low-frequency muck with no air around individual instruments.
Regards. |
Hi Tim
regarding the "wedgie" :^) - A while back I did put one piece of Oak temporarily on the counterweight side to hold up the just installed damping trough. To allow the adhesive to set. One loses functionality of the VTA when you do that.
I found big differences between ET 2.0 (.5) mounted on
1) Wood plinth with the aluminum plate - in this case my own plinth birch/plywood (70 lbs), and the Jean Nantais plinth 100 lbs.
2) Acrylic or some other hard material that required use of the aluminum plate to keep it from marring the surface.
3) Mounted naked without the plate - Metal spikes direct on aluminum, brass, other similar material.
1 is the worst by far, and 3 is the best - to my ears. Also I can grab the manifold and move the Verdier table on its pneumatic suspension with it and not cause a shift. Its very firm. On the Jean Nantais table the armboards are replaceable and like the motor/platter mounts are separated from the main plinth with a void (air space)by design. The next step for me was to try a different material armboard with the ET2. Add this to the project bucket list.
Imo - the aluminum plate was a business decision by Bruce (a good one) to allow mounting on different tables. Most VPI tables had acrylic plinths so would fall within (2) above. The spikes could be filed down in this case to allow for direct mounting. I am curious if you are still using a VPI Classic with the wooden plinth and plate ? Good that the wedgies worked for you and you are happy with it.
Also regarding the VTA which the wedgie defeats. On the general analog forums here there are obviously two camps with those that like to play around with VTA alot and those that just set it at the "middle gound" and "forgetaboutit". This is true with the ET2 as well. Some have even removed the spike system and locked/tightened the VTA down so it can not be used. The post from Banquo363 earlier in this thread of the ET2 he bought was an example of this.
My 2 cents.
Cheers |
Pegasus - I call my baritone sax my personal distillery. Like Frogman and a few others here you certainly have a way with words ! Frogman - Actually, my tractor is a Husqvarna GT48XLS Frogman - you own one really sweet machine! I am a fan of Husq. I happen to own an "old" 20 inch Husq. chainsaw. It was bought used from a Logger back around '92 where our summer retreat is for $250.00. If you can just imagine what "used" means coming from a Logger... :^)...... but doesn't it still run smooth, and it has saved me a few times as the last kilometer into our place can be best defined as a good "Loggers" road through steep terrain and forest. You never know what is lurking round the corner after a bad storm. Frogman - I find the visceral experience of dirt, gasoline fumes and engaging that rear-wheel-differential a welcome change of pace :-) Frogman - A friend from up north sent me this video two days ago. How to load a Bobcat...Where else but here, will you see a cool tractor video.... some good physics happening there like with vinyl. And now a Ray Anderson Interlude..
Pegasus - Re: Trombone - The instrument is extremely powerful in a seductive way, a lot of colors and expressive
The middle/high school years can be very expressive but also impressionable. I wish the girls back then in my class saw the trombone as more seductive ! |
Ct0517
I have the ET mounted on the plinth of my VPI Classic. I took some time and used several blocks of wood to get what I think is the best VTA. I also have the table mounted on Stillpoint Ultra SS's and one of them is on top of the arm mount. I taped the hole with 1/4 20 and screwed the Ulra into the mount.
Tim |
I also have the table mounted on Stillpoint Ultra SS's and one of them is on top of the arm mount. I taped the hole with 1/4 20 and screwed the Ulra into the mount. cool - Tim this is the type of modded setup a picture would be great with, maybe in your virtual page? Anyway I'd like to see it and am sure others would too. My comments apply to Pegasus' ET 2.5 set up as well. btw - I discovered that the Audiogon virtual system is a separate database from the forums. How I know this, is you can link a pic from your virtual system into a thread like this one. Go ahead and delete the pic from your virtual system. The link with pic will remain in the thread. Cheers Chris |
Chris, that video is one of the funniest things I have seen in a while; thanks.
And loved the Anderson interlude; very expressive and unabashed trombone playing. |
LOL supa video. Chris, I already know you´re a man of humour.
Adjusting and running an air bearing tonearm needs lots of humour. This thread gets better and better all the time... |
you´re a man of humour Dear Harold, et al I have always believed but the last two years have solidified my belief, that lurking in the belly of every seasoned audiophile is a comedian waiting to bust out. Every seasoned audiophile, if he/she took a good look at themselves, is carrying enough material/stories with them to allow them to do stand up comedy in countless shows for years. However lets think about two scenarios. Would a seasoned stand up comic get a better reaction from an audience of serious audiophiles or an audience of serious music lovers? 10-23-14: Harold-not-the-barrel
Adjusting and running an air bearing tonearm needs lots of humour. I am tempted now and again to join the party and provide my thoughts whenever I read yet "another" thread on how to "really" properly Align, or set Anti Skating on a Pivot arm. But the little voice inside says "Don't go back in there man, you made it out !" The key to leveling and lining up an air bearing linear tracker is to do it when the bottle of your choice is still un-opened. As you know the road is clear and straight. There are no curves with two markers hiding along the road that you need to make sure you visit along the way. :^) This reminds of the time before kids and marriage when I used to go out with my buddies. (lol) Afterwards some were able to walk the straight line better than others. When my previous company shut down our Canadian group 2 1/2 years ago, it was a wake up call; but as I was in shock, I did not wake up from the event till 6 months after. It was the most serious of jobs to imagine what I used to do. No humor serious stuff. Now I can't get enough of Comedy Festivals, sometimes laughing uncontrollably. My family gets concerned sometimes at this behavior and they say - "Dad why don't you go listen to some music".... Wow.... can life get any better than this ? All is not great however..you see in my subconscious, I think there may be a desire to become a comic one day, but I hit a big road block recently. I have discovered that my wife is funnier than me. And why am I surprised? As I sit there memorized, in a trance like state by the reproduction of my favorite singer, group / band's music in my room, unable to move, she has been observing all of this from THE OUTSIDE IN God only knows the stories she could tell. btw - that pic is still the best definition of Nearfield that I have ever seen anywhere. From one linear guy to another. Cheers Chris |
For the tonearm collector An ET1btw - interesting tonearms on the table this seller has the ET1 mounted on. For the Music Lover Base ET2 Low PressureRight here at Audiogon. Just remember, if last weeks posts have not made it clear; as with any musical instrument, lessons are recommended with the ET2 :^) (in my previous post memorized should read mesmerized) :^( |
**A vinylphile, on his way to loan his buddy and fellow LP-lunatic his prized vacuum record cleaner, decides to make a quick stop at the bank for some cash. He pulls into the parking lot and nervously decides that it's probably ok to leave the machine unattended on the backseat of the car for just a few minutes. Runs into the bank and makes the quick transaction. On his way back out to the car....SHIT!! ....the rear window of the car is smashed to bits and the door wide open! He slowly peers into the rear of the car, and on the back seat he sees....two record cleaners!** A twist on a classic viola joke (the viola, popular subject of ridicule among musicians). This one, also easily adaptable to the subject of this thread: Q: How can one tell that the floor of the stage is level? A: The viola player is drooling out of both sides of his mouth. https://m.youtube.com/watch?v=9CdVTCDdEwI |
Frogman - I think this the 4 th time you have made me spit up coffee on my keyboard. Q: How can one tell that the floor of the stage is level?
A: The viola player is drooling out of both sides of his mouth. What happens to the poor guy when the stage is tilted back a bit ? maybe I don't want to know... |
Hi All.
I have been experimenting with the air supply again. This after earlier experiments implied that the output pressure from the regulators I am using oscillate around their setting.
The change I made was simple taking a few minutes but furnished a worthwhile improvement.
initial setup was... Compressor, inbuilt regulator, 6feet soft PVC tube, 1/4" needle valve vented to atmosphere (barely open), second regulator water trap, 30feet soft PVC tube, arm.
The new configuration places the needle valve immediately after the second regulator. The theory being that both regulators are unstable and bleeding some air to atmosphere via a non compensated needle valve will smooth the regulator perturbations in the air stream to the arm. I had to increase the setting on the second regulator a tiny amount to bring the pressure seen by the arm back up to the pre change figure.
The hissing of the needle valve is not an issue since this setup is in another room.
The result is an increase in "tightness" notes are more visceral and solid. Soundstage larger in all directions, greater differentiation of the sound between records and individual tracks of the same record . An agreeable result.
All testing was done with the compressor cycled off. |
*** YELLOW STICKY FOR ET2 THREAD MARK - AIR SUPPLY *** A series of posts to help me and others find stuff here - just working with the system ! This one focused on Air Supply/Manifold/Air Bearing Spindle ET2.0 (.5) Motto Better the air supply "AT THE PSI AS DESIGNED FOR THE MANIFOLD IN USE" and the ET 2.0 (.5) just keeps sounding better. Bruce Thigpen
More than air pressure, the air supply will change the sound of the tonearm. if it is bad, allowing pressure pulsations to enter the manifold. Increasing pressure slightly and a big enough surge tank are the best things that could be added to the tonearm in terms of performance. Firstly let me say I believe Bruce has created a real monster with this air bearing manifold/spindle design. Truly excellent results with a stock setup for music lovers to enjoy their records at 3 psi with the base ET2. This can be the end of the story, and it is for most. That's real life. Lets recognize this for a moment before non-ET2 readers here think all ET2'ers are like us. I am sure in the thread views that there are many ET2'ers who have been enjoying their records in stock ET2 setup for years, that get quite the chuckle every now and then here with our adventures. Cool...enjoy..... I hope they approve of Dorothy. Boy I am mellowing as I age.... Unfortunately the changes with improvement of air supply is very addictive. I went personally through 6 pump systems. I am very very happy to report that I am a music lover again and pleased with what I am hearing. But its funny that all those experiments even though years ago are still fresh in my mind. We have all heard about Audiophiles going down deep rabbit holes with tweaks. Well this is about air lifting the music up to the ...... (use your own word to describe) So some ET2 Secrets revealed. I dug up a few emails with Bruce relating to Air Supply delivery that explain the above better - hopefully this is helpful, informative and illuminating to everyone. Maybe grab a coffee or "other" drink before reading. All emails cut down for brevity. This first one I asked just yesterday - RK's post inspired me. The others are from early this year and previous years.
ME
Hello Bruce - assuming a setup like this.
pump /surge tank --- 100 feet of air line ---- ET2
Is it not better to have the moisture /dirt trap plus a second regulator as close to the ET2 for air supply quality ?
Chris,
I would put the pressure gauge/filter within 5 feet of the tonearm only so I could monitor the input pressure and the quality of the filter. After the air travels through a long length of small diameter air line the flow should be very smooth. To verify if the air flow is smooth, listen to the output of the air hose, if you hear any humming in the air flow then it is not a good air supply.
- brucet
ME
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.
ME
Hi Bruce - so to be clear - for example in the normal design of the base ET2 at 3 psi.
Air continually goes in at 3 psi - circles the spindle "captured bearing" and escapes out the sides of the manifold, as more air is pumped in? This is by design.
Bruce
correct
ME
If someone has a 20 year old stock ET2 manifold designed for about 3 psi and decides to pump in 12-15 or more PSI
the extra air will just escape around the edges of the manifold and at a rate that can be heard ?
Bruce
The extra air will escape, but the rate of escape will not be that large from an operational point of view, but the escaping air is usually audible which causes one problem and the air can cause a push back at the extremes of travel.
So there you have it. The ET 2.0 (.5) design is meant to bleed around the manifold. Now what happens then if someone mods their arm and adds shims to the ends of the manifold as has been discussed here ? Does this not block the air from bleeding as designed? IMO this would change the design substantially. This would also mean that any observations in regards to changes to air supply, most likely will apply to that setup only, and not a stock ET2 manifold setup ? I have not added shims and am just visualizing this. This is my opinion and I don't feel I need to ask Bruce on this one. Does anyone disagree ? Richard I bring this up as you are using shims ? Another Fact revealed. This one is on page 3 of the manual. . From Manual - Page 3
The large surface area 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. Whenever I read that someone increased the PSI and it sounded better, some "Audiophiles" would say the bearing is not rigid. THIS IS TOTAL NONSENSE. It is not that the bearing is not rigid; its because by happening to increase the PSI with the pump in question, the user actually bettered the air supply coming in, with that respective pump. How many of us are pump experts ? How much do you really know about your pump? if that person had used a better pump same PSI the sonics would have also improved. Its about better air supply. My Pump - Timeter Aridyne Compressor How Aridyne’s Dry Compressed Air Movement Works This is what happens when I flick the switch. First, air is drawn through the air pump inlet filter. Then it is pulled into the pump where the pistons pressurize it to 80 psi and push it forward through the Teflon® lined high pressure hose that is reinforced with braided stainless steel. At this point the temperature of the compressed air is approximately 300 F. Then compressed air flows through the copper coils where it is cooled to room temperature. During cooling, moisture in the air begins to condense. The cooled air moves to the water trap where the condensation is rained out and collected. This moisture that is collected in the water trap is continuously drained through the nylon tube to the water collection tray where it evaporates. Next the air is decompressed to 55 psi by the secondary regulator. After this decompression the small amount of remaining moisture is so dispersed throughout the expanded volume that the dew point of the air is several degrees below room temperature. In the Aridyne Air Compressor this dew point depression can range from 3 to 10 F. All of the above with the flick of a switch. Turnkey. I do need to train my new puppy on how to flick the switch. From this point the air is regulated down to 19 and sent down 100 feet of tubing - some of it coiled up. The ET2 likes dry Arizona air. Its been said here before. 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. This constant controlled air psi from a pump is how air is delivered for patients in hospitals. That's another discussion ! Now a question for long time ET2'ers using original manifolds. Some over 20 years old. When is the last time you checked the condition of your capillaries? Are the manifold inlets at 50-60-70 80% of what they should be? If not 100% you will be using more PSI to drive the arm because they are partially clogged and not getting the performance they were designed for. This is another reason some say the sound got better with more PSI. Clean them per the manual instructions. lastly - someone advised me of a poster, a respected professional reviewer who has posted on Whats Best Forum saying he used 50 psi with his ET2 for it to sound its best. First as mentioned above the design limitation is 19 PSI. Don't take my word for it - Ask Bruce yourself. When I read stuff like this, I make like a deer in the headlights on the other side of my screen. I wonder what he really hears, and what else is in his audio chain to cause this. I try to stay within the design parameters for all the gear I own. This is another clue imo that you are a music lover first. My experiences have been increase the quality of the air supply and the sounds gets better - every time. I hope this was helpful. More secrets revealed coming up. The title of the next post? "Why does the action of my ET2 VTA, resemble me Coming Out Of A Brothel at 2:00 am" The dirty secret is finally revealed...... |
"Why does the action of my ET2 VTA, resemble me Coming Out Of A Brothel at 2:00 am" lol. Can't wait to read that one. |
Chris.
You must have time on your hands to produce such a lengthy thoughtful tome.
I read it multiple times to try to get inside what you were saying. I think that you take BTs comments to mean that the o'rings will leak if a low pressure manifold is over pressured? I don't think that this is what he means.
I suggest that BT adjusts the arm design pressure by manipulating the clearance between the spindle OD and manifold ID and/or the way the capillaries are set up.
The push back at end of travel he talks about is due to excessive air flow exiting the gap between spindle and manifold bush, not due to the o'rings leaking.
The shims I have added are in the gap between the manifold outer plastic shell and inner aluminium bushing. This is the gap where the o'rings sit. The 2 shims about 2x3x**mm thick, each end, are spaced at 120 degree increments. Completing the circle at 120 degrees each end is one M2 grub screw. It is gently tightened to make a solid mechanical link between the manifold outer shell and the inner bush.
One would not consider removing the main arm to TT plinth mounting bolt and gluing the arm to the plinth with say rubber discs spacers in place of the three pointed screws, since this would be introducing a compliant joint between the arm and TT. But this is exactly what the o'rings do. They are a compliant joint.
The positive benefits of adding the shims and grub screws is unambiguous.
cheers. |
Richard its never the best way to just cut and past portions of emails and other info into a thread. Whats missing is the rest of the email, and the valuable info obtained from verbal conversations. Summary: Pump/Surge tank ---- long tubing (if you don't have the room coil it up) ----- ET2 PSI Gauge/filter within 5 feet of the tonearm. The PSI coming out of the air pump should be ideally targeted to match the PSI the manifold has been designed for. For those buying a used ET 2.0 (.5) its important to determine this. We have discussed the technique here. Before this technique is performed the manifold needs to be restored. Definition of a manifold. "A pipe or chamber branching into several openings" Two Et2 ManifoldsThe owner has provided permission for me to post these pics. Thank u ! The one on the left dirty from years of use without a filter/trap. The one on the right has been cleaned. What can't be seen in the pic is what the insides looked like before and after. Its the same manifold. Cleaning procedures well documented in the manual. If your planning on upgrading your pump make sure your manifold has been restored first. The threaded portion of the manifold is designed to allow air to spiral around the outside of the set screws and maintain the precise length and size of air passage required for an efficient air bearing. Page 42 Next in Line. 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. Richardkrebs - you must have time on your hands... I fail to see the relevance of your comment. If you're really that interested the previous post took 40 mins - which is about how long it normally takes to down my mug of coffee with one re-heat. The intent (agenda) of all this includes awareness, interactive sharing, knowledge, learning, and "mostly" fun. I am having a blast. how bout u ? A fun start to my day now that I am not living with the bears. Now where were we ? Something about the similarities of the ET2 VTA and a brothel ? |
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 |
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 ? |
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. |
|
The draft brothel post is complete ! Due to the sensitivity of the subject it has passed to Dorothy Click on me Darling for proofing. ☺️ |
I volunteer to check and make sure those capillaries are not clogged :-) |
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 :^) |
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. |
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 :-) |
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.
|
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. |
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 |
Pegasus
Sorry didn't answer your question.
Air stream grounded to the house wiring earth.
Cheers |
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 |
***** 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 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 |
*** 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. |
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. |
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. |
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.... |
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. |
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 ? |
@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 ... |
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, 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. |
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. |
**** 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. |
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.- |
