Hi Leon_Krige (LK) sorry for the long post. PS: Not fixed on the Colibri, but it sounded incredible on a friends Dynavector tonearm, despite his warnings that the cantilever angle is not aligned with the cartridge, is difficult to set up, & apparently it swerves very far out on its path playing on linear tracking arms. (from Vusi Khumalo who has posted some well informed threads on this forum) thanks for that info. very interesting. Sounds like an intoxicated cartridge that can't walk the fine straight line needed for a linear tracker - a line that can be anywhere on an LP. Improper setup on a linear arm results in a walk that may start ok at the outside grooves but is off at the end. Or its off at the start and ends up on the line on the inner grooves. This is all due to incorrect setup - user error. This is why it is important to do 3 measurements - at the outer grooves, middle and inner grooves. But I've never heard of one when setup properly "swerves very far out on its path" A cartridge like this if it were "really true" would be of little use to me regardless of its discount; or maybe its just me and the result of having too many beers with the bears this summer. I am just not getting this swerve out part. Never heard of a cartridge exhibiting this kind of behavior. Its true there is no place to hide with a linear tracker. If its out you will know. This is not the case with a pivot arm where from most people I have talked to, only a small percentage can actually hear the two spots on records that their cartridge is actually in the sweetspot; the other times not. I remember this was audible with my dynavector arm in my main room and I believe I discussed this on my virtual page blog. So if someone can't hear it thats good. Of my more recent pivot arms in my rooms I found the Dynavector the most neutral (compared to MTC's) with the JMW12 and FR64s both producing bass bumps (assuming a LF resonance). I also recall in my room 2 requiring two different sub settings with the Quad 57 on full range material. One for the FR64s and one for the DV505. Here is the culpritAnd here is a Colibri threadInteresting comments from that thread... and yes, on some pressings wonderful, others it was not happy and edgy. Some have cantilevers that are not parallel to the body, and they dont have the same height and VTA. The question I have is were the pressing that sounded wonderful and others not happy and edgy cut at the same plant, same way ? Some info for consideration. Page. 56 ET2 manual. Conclusions 1) Not all cartridges will be improved by using them at some angle other than the intended design angle. (The top of the cartridge parallel to the surface of a record) 2) The European record vertical cutting angle standard closely matches the vertical angles present in phono cartridges today. There is a need for a universal record cutting standard which closely matches this. 3) If the measuring vertical tracking angle of a cartridge is high (greater than 22 degrees) its vertical performance will probably be improved by tilting it back (2 or 3 degrees) (front goes up) to match present vertical angles on records. 4)If the measured vertical tracking angle of a cartridge is 18 to 20 degrees. It will probably perform best when its top is mounted parallel to the surface of the record. 5)Some cartridges are very sensitive to small changes in VTA, others are not. Page 51 - discusses how most records are cut between 16 and 20 degrees. Seems the Colibri from its specs at 22 degrees falls into points 3 and 5 ? When records are cut differently we can hear this on resolving systems. And we have discussed this here a number of times. When VTA adjustments are made we know its a good thing to have a tonearm that will not any change parameters like VTF and keep things intact. When two audio friends change the VTA on their Kuzma Airline - the VTF changes. this was confirmed. Its physics. Now lets ask ourselves - what is going to happen when you play with the VTA on a cartridge like the Colibri that is revealing, needs fantastic alignment to start of with; and it needs to keep it there. You need a tonearm that changes no parameters. imo - there is a reason the VTA on the ET2 is patented. Bruce happens to be a good business person. fwiw - from an alignment (NOT COST) point of view this applies imo to our cracker jack cartridge 420 str as well. Have a look at its stylus next to its brother and sisterThe one on the right - is the top sibling- very revealing - can be a real PITA, if not set up properly or your tonearm, or your tonearm changes parameters when you adjust VTA. It is affected by point 5 imo. Try this experiment. Get a long permanent marker. two pieces of different height wood and a piece of paper. Place paper on table, the lower of the two wood pieces on the paper. make a line where it rests on the inside. Hold the marker loosely in your hand between the thumb and index finger and rest it on the lowest of the pieces of wood. Bring the marker down slowly so it makes a spot on the paper. With the outline of the previous wood clearly visible, put the higher wood piece down. Repeat the exercise and place the marker down again. The marker makes a spot in a different location. It will be closer to your hand and the marker is at different angle as well. If you could weigh the weight of the marker on the paper, it would be lighter with the higher elevated piece of wood. How do I know this? Because I tried I tried this test with every pivot arm I have ever owned. You can't defeat physics. I find it interesting that the only thing I currently own that was made by VanDenHul is the stock factory silver wiring inside my main speakers. I may also have an old ET2 wire loom with his wire. I just can't afford a mistake, single dad, university teacher, not a stockbroker! :^) LK My job has taken me to many different fields of work and I have had to interview the folks who make those industries, companies, organizations tick and can't be without if something happened. Stockbrokers were the least generous with their time and very selfish overall about what they do. Like trying to get blood from a stone. Teachers were always very forthcoming with info and also showed a real need to want to give us the best info to help the students. I am curious to know how well the previous owner mounted the ET2 on your table (especially if you are going to consider mounting a Colibri). Do you get good alignment on the line for the outside, middle and inside grooves. Also how well is the VTA worm gear working. It should be smooth and remain level when raising and lowering. The lever firmness can be adjusted. You strike me as the type that is going to have a lot of fun learning with the ET2. This means I am probably going to be learning from you too. So I look really look forward to your progress. Pls keep us updated. I am off to go meet up with some bear friends. Richard if you see this I have decided to wear the bell this year when I run. Cheers |
Hello Chris,
Thanks a mill for your reply, I started feeling like a dumb blonde novice, (ok lets face it at this stage I am...)
Still setting up the space with the compressor etc, the Studio should be fine now, broken wires repaired, checked speed etc, all good to go, I've lasercut some plexiglass sheets to hide the glue & holes which the previous owner left.
Visibly the ET arm looks fine, hope its mechanically sound, I just always wanted a Studio as extension of the baby Goldmund which has given me 30 years of joy, but I've heard incredible reports about the ET arm, so I will learn slowly. There was no pump, likewise no powersupply with the STudio, I'm using the home built PS from my Studietto which is good.
Hence the compressor which will be linked from a stairwell below, I figured it would work to use the 50l tank as the air supply, not really to run it while playing, if this is a bad idea please let me know, I haven't opened the compressor box yet, just heard its a good alternative?
PS: Not fixed on the Colibri, but it sounded incredible on a friends Dynavector tonearm, despite his warnings that the cantilever angle is not aligned with the cartridge, is difficult to set up, & apparently it swerves very far out on its path playing on linear tracking arms. (from Vusi Khumalo who has posted some well informed threads on this forum)
I can only afford one good cartridge, no mistakes, hence the questions asked, some heavily discounted Colibris were on offer on this site, that's where I picked up the idea. But I've heard controversial feedback whether they are first grade cartridges, hence the concern, I just can't afford a mistake, single dad, university teacher, not a stockbroker!
For the moment I will mount my old MC 10 & learn from it.
Thanks again for the encouragement & advice, it helps a ton to know there are well informed users out there, this is definitely not a walk in the vinyl park... |
Just to add imo the Achilles heel for the ET2 is documented quite clearly in the manual on page 47 by Bruce. "If you like to play severely eccentric records, ones with run out greater than 1/8th of an inch, then we suggest you use a low mass pivoted arm.” My experiences is the ET2 is not limited by the cartridge, but the record itself, and the wiring positioning. I can't imagine anyone at this level of vinyl play using eccentric records with expensive cartridges ? |
Hi Leon-Krige - welcome to the thread. I've just bought a used ET 2 arm with an old Goldmund Studio (which I'm restoring to look like new, it was damaged badly) Was the ET2 tonearm damaged as well ? I've bought a 50 litre compressor to run the arm, but this is all brand new to me, any other advice would be most welcome. The base ET2 needs just 3 psi to work. Did the package you bought come with the standard pump to work with first just to get up and running? VdHul MC10I've had great success & many years of pleasure from Goldmund Studietto with VdHul MC 10, so I'm tempted by the Colibri XPM or similar as there are special deals on offer, but I've read many conflicting reports & warnings against Colibri on a linear tracking arm.
Its the best sounding modern cartridge I've heard, but very high risk, I can only afford one cartridge which should last for many years, so really can't make a mistake on this. My old MC 10 has been retipped once, still sounds stunning after 27 years... thats what I'm hoping for on ET 2. The VdHul MC 10 looks identical to my Benz Micro MC3 that I have used for many years in the ET2, ET 2.5. The ET tonearm is unique in design, and setup requirements and this includes other linear trackers. It has a patented VTA system. There will be a learning curve with it. For this reason initially I would use a cartridge that mistakes can be made on. Everybody needs to walk first with an ET2 before you can run. There are no exceptions to this. Once running however you don't look back. This has been my personal experience and those I know that use the ET 2.0 or ET 2.5. Regarding conflicting reports & warnings against a Colibri on a linear tracking arm - you hear alot of 'stuff" on the internet. I am interested in seeing some of these reports. We can help you debug them. Get the facts and weed out the myths and audiophile heresay. Feel free to share links or any information. At the high level view my opinion is unless the author provides specifics I always ignore these reports. I feel with most people who are genuine with no agenda; if they have had a good or bad personal experience, they are willing to share details with others and try to help them. ColibriTechnical Data: Stylus Shape: VDH - IS Stylus Radii: 2 x 85 Micron Frequency Range: 5 - 65.000 Hz Tracking Force: 13.5 - 15 mN Static Compliance: 35 Micron/mN Tracking Ability at 15mN at 315Hz: 70 Micron Channel Unbalance: < 0.5 dB Channel Separation at 1kHz / 10kHz: > 35 / > 30 dB Equivalent Stylus Tip Mass: 0.24 Milligram Vertical Tracking Angle : 22 Degrees fwiw - I have used a sonus blue gold cartridge loaded at .3 vtf with the ET2. It has a compliance rating of 50 with no issues. I also use an XV1 at 10 x 10-6 cm/dyn. Please skim through the ET2 manual. Key parts of the manual to me. Page 28 - for proper counterweight setup Page 39 - cleaning the air bearing (especially if bought used) Page 46 and onward - Advanced tonearm/vinyl info. Antiskating and Frequency Modulation Distortion A must read for anyone serious about their vinyl setup. Hoepfully this info is helpful to start. Cheers Chris |
Dear ET friends,
I've just bought a used ET 2 arm with an old Goldmund Studio (which I'm restoring to look like new, it was damaged badly)
I've bought a 50litre compressor to run the arm, but this is all brand new to me, any other advice would be most welcome.
Biggest question is what cartridge would work on the ET2 with Goldmund, I use a homebuilt Nuvista valve headamp, based on Conrad Johnson, Counterpoint SP 7 valve preamp, 250watt Mossfet power amps driving stacked double Dahlquist.
I've had great success & many years of pleasure from Goldmund Studietto with VdHul MC 10, so I'm tempted by the Colibri XPM or similar as there are special deals on offer, but I've read many conflicting reports & warnings against Colibri on a linear tracking arm.
Its the best sounding modern cartridge I've heard, but very high risk, I can only afford one cartridge which should last for many years, so really can't make a mistake on this. My old MC 10 has been retipped once, still sounds stunning after 27 years... thats what I'm hoping for on ET 2.
Does anyone have experience with Colibri on ET 2 arm please?
Any advice would be greatly appreciated. |
Dear ET friends,
I've just bought a used ET 2 arm with an old Goldmund Studio (which I'm restoring to look like new, it was damaged badly)
I've bought a 50litre compressor to run the arm, but this is all brand new to me, any other advice would be most welcome.
Biggest question is what cartridge would work on the ET2 with Goldmund, I use a homebuilt Nuvista valve headamp, based on Conrad Johnson, Counterpoint SP 7 valve preamp, 250watt Mossfet power amps driving stacked double Dahlquist.
I've had great success & many years of pleasure from Goldmund Studietto with VdHul MC 10, so I'm tempted by the Colibri XPM or similar as there are special deals on offer, but I've read many conflicting reports & warnings against Colibri on a linear tracking arm.
Its the best sounding modern cartridge I've heard, but very high risk, I can only afford one cartridge which should last for many years, so really can't make a mistake on this. My old MC 10 has been retipped once, still sounds stunning after 27 years... thats what I'm hoping for on ET 2.
Does anyone have experience with Colibri on ET 2 arm please?
Any advice would be greatly appreciated. |
Dover,
I would also love to see some pictures.
Why did you remove the foam from the aluminum arm tube, and could you detect a difference?
I just got my vinyl rig up and running but the tweaker in me is already thinking about the next move. I'm currently using an ET-2 with the aluminum arm tube and a Denon DL-103R. I think the Denon would work better with the higher mass magnesium arm wand, which I have on an unused ET-2.5. Does anyone have any experience with the Denon DL-103 on both the aluminum and magnesium arm wands?
It's too bad the forum is so archaic. This might have been covered in this thread already, but it's virtually impossible to search it. |
Dover.
Very interested in seeing a photo of the Aluminium goose neck and the titanium wand if you can find it.
I'm sure others would like to see these photos, of the goose neck at least, posted here as well. |
Chris / Ketchup
Yes the numbers scare me, but they are necessary to cover even more frightening expense numbers. The beast, which is our business, roars out every minute of every day saying "feed me!"
Absolutely, a mag wand is on the wish list for use with my MC cart.
A mag or titanium goose neck, now that is an interesting idea. |
Ketchup,
I have played with titanium components on the ET2 some years ago. I overhauled a company that manufactured custom wheelchairs, including custom titanium frames, with custom brackets to meet individuals needs. Unfortunately titanium is very brittle to machine, it shatters very easily and I think you will find it difficult. As an aside titanium tube is not rigid, you can actually bend it by hand, but it does have fantastic damping qualities. I have a titanium arm tube sitting around somewhere, but have not used it.
With regard to the aluminium one piece gooseneck, mine is the same as Krebs, and I use it in an ET2 & aluminium arm tube with both MC ( Carnegie, Koetsu, Denon 103 ) & MM ( Shure V15Vxmr with brush removed ). I have never had stridency from my ET2.
Bear in mind my ET2 aluminium arm tube has had the foam & shrink wrap removed, the teflon insert in the headshell removed and replaced with carbon fibre. I also run a loose decoupled counterweight ( tuned with teflon bushes ) that is much lossier than the standard spring for both MM & MC. Frogman has trialled this and attained the same benefits of quicker and more transparent bottom end ( literally more notes in his system ).
So my suggestion to Chris if he wants to run an MM in the ET2.5 with the aluminium gooseneck would be to try loosening off the counterweight nut and lower the overall horizontal mass ( above FR ). If you back the nut off and then dial it in slowly whilst listening to the changes you can tune the counterweight motion quite precisely, even more so if you put a tiny wedge either side of the spring to control the motion ( I used teflon ). |
Has anyone ever tried making titanium or magnesium goosenecks? |
Now days to get a part machined in my shop I need a CAD drawing at $150/hour to produce. A CAM program at $150/ hour to produce. Machining itself at $450/hour, plus material which actually is the smallest cost of the lot. Very Interesting numbers Richard, thanks for sharing. The numbers reminded me of my former job. If I can digress for a bit and share something - for a different perspective. The company I used to work for charged me out to clients as a project manager at a straight $225 US an hour. A senior consultant was $180 and a consultant $125. A typical work project budget would be based on a respective 10, 20, 70 percentage workload split with myself managing 10 or more projects. (And my wife still wonders why I don't want to go back to work). For this you got electronic and paper plans that you hoped you would never have to use. Mostly theory based but did include one practice run through at the end. Imagine that. Hard to believe for me now. Nothing really tangible. The employee skills gained during the project to use the plans eroded with with company turnover. Anyway. Some observations aluminum versus stock gooseneck. The aluminum gooseneck combined with the heaviest mag armwand has taken the resonances for my modded 2.5 tonearm into MC only territory now (based on my ears) which is ok with me. I have a couple of MC cartridges I really like. Whether this is more the mag wand influence over the aluminum gooseneck I can't say. They came to me at roughly the same time period. I do sense it is more the mag wands influence, as it was designed for low compliance MC cartridges by Bruce so things do kind of add up to what I am hearing. As you are an MC user Richard I highly recommend acquiring a mag wand if one becomes available to try out. In contrast - our cracker jack box cartridge MM 420str discussed here sounds quite strident now on the 2.5 with the 420's higher compliance. But the 420 sounded great before on the 2.5 with Carbon Fibre armwand and stock gooseneck; and it still does sound great on my second ET2 with stock gooseneck and aluminum armwand. So what this tells me when looking at improvements and upgrades with vinyl, is there are no absolutes, generalizations can't be made, and whether something is an improvement will depend on each person's individual situation as our audio kit setup and preferences and goals are all different. One more observation. The aluminum gooseneck is as you say set at the midpoint level of adjustment. From a stylus adjustment point of view, if someone likes playing with a lot of cartridges, we can partially blame the MM thread for some of this behavior ?, you could very likely have someone who has a few cartridges hooked up to 2 or 3 armwands ready to interchange; the three armwand stylus level settings on the stock gooseneck comes in very very handy, with the different size/length cartridge bodies and styluses. The three adjustments allow the midpoint inscribed line on the manifold to stay constant and level with the record surface for wow and flutter control. I don't have problems with multiple cartridges (I have problems in other areas) so setting up one cartridge for an extended length of time and dialing it in with the aluminum gooseneck works really well with me and l really like it. Feel lucky to have it and wanted to spread the joy if possible. If someone reading this can help us out please chime in. The person I referred to earlier has a friend machinist, so the actual machinist cost (highest numnber) could be contained. But he needs the CAD drawing. Just a note as well that the stock ET2 gooseneck is made up of two parts. Aluminum on the armwand side and carbon fibre on the air bearing spindle side. Cheers |
Chris.
Back in the day, nearly 20 years ago, I took a piece of aluminium to a machine shop along with the original plastic goose neck, set at the mid position and said to the machinist "copy this please". I did ask him to make the part that slid into the wand one thou bigger in dia as I felt that it was not a good fit in the wand I was using. There was no drawing produced. Now days to get a part machined in my shop I need a CAD drawing at $150/hour to produce. A CAM program at $150/ hour to produce. Machining itself at $450/hour, plus material which actually is the smallest cost of the lot. If we were making 100's it would be viable, but a small number would be very costly. The best option is to find a local machine shop that has lathes and milling machines and take an original goose neck along "please copy this" I used the same aluminium as the wand, 6061 T6, from memory. This info is somewhere in the manual.
Sorry I cannot be more helpful but, I would recommend that anyone interested goes through the effort. There is really a big jump up in performance when the quite flexible original is replaced. |
Hi Richard, there is continued interest in the Aluminum ET2 GooseneckReceived two recent emails, the latest this week from an Audiogon member on this ET2 thread asking about the possibility of doing a limited run on them. I will pm you with more details. Posting here to let those that expressed previous interest in the Gooseneck aware. I will post any updated info here. Cheers Chris |
It is probably difficult to compare oil trough settings. I am using a different oil and different paddle at the other end of the spindle. Further I have a fixed CW which means that the physics of the arm are quite different. All good points Richard. Again too many variables. In conversation with Bruce last year I remember him saying the position of the trough was decided out of convenience. I think it can be reversed. I say this because my spare stock gooseneck has a hole marked in the bottom - for the paddle?.... Has anyone tried this ? |
Chris.
Having owned power boats pretty much my whole adult life, I am very familiar with the effect you sight. There is a "golden" set of adjustments, propeller angle, trim tab setting, RPM, weight distribution, where once optimised, the boat becomes quiet, travels faster, the ride is smoother and it burns less fuel.
It is I believe a good analogy for a tone arm set up. There are many individual adjustments that combined correctly can result in "golden" performance.
It is probably difficult to compare oil trough settings. I am using a different oil and different paddle at the other end of the spindle. Further I have a fixed CW which means that the physics of the arm are quite different. The undamped resonant peak is higher on my arm, so it would need more damping to bring it under control.
mlswgdtftwg |
Richard - An observation. I spent the weekend on the water boating and sometimes in the water - this was by accident as the temp is still only in the 70's. What was very obvious is that even with similar size boats but with different size/horsepower motors; the ones that had their prop set up properly....were able to skim the water, go on plane and performed far better than those similar boats with motors too large / long that had props that slugged lower through the water.
Where am I going with this ? Lets play crazy scientist again and assume that the prop in the water is like the tonearm's paddle in the oil.
I was puzzled with the big performance differences between your oil and non oil damped settings. Could your paddle be in the oil more; and the oil is acting as a cushion for your modded spindle as it goes back and forth with the lp? Just a thought. I am using just 1 cc of oil and the paddle is barely skimming the oil. fwiw - the oil in the trough also acts as a great visual level as well.
Are you a skimmer or a slugger ?
:^) fun hobby. Happy listening. |
Richard, et al. fyi - Bruce' opinion on PSI changes versus Quality Air Supply. I didn't want to interrupt Bruce' Elephant hearing study so I kept my question short. Bruce
If a friend made a significant change to the air delivery system on his ET2 and this caused audible changes like soundstage and other audiophile type attributes, attack, decay, to change .... do you have an opinion re: PSI changes versus the Air Supply itself. 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. Not knowing anything about the pump changes, I don't have much to offer. Thank you and I apologize for the delay in getting back to you.
brucet key words to me "increasing pressure slightly" and "big enough surge tank" This applies to unmodified ET2.0 and ET 2.5 |
Chris.
"great crazy hobby this is. We are running two very different......"
Yes but isn't diversity the spice of life!
My pre is my own, all tube design, well actually my own unique combination of known gain blocks with some interesting P/S features. It exists in a family of one, world wide.
I wish I did live just down the street. I suspect that it would be a lot of fun.
Yes, I freely admit that the pressure disparity with and without the trough is interesting. Maybe I will revisit this, but the oil trough change was big in my rig even at 12 psi each way, it just got better, with the trough, as I pushed it up to 18.
If your kids are like mine, they will continue to give you sleepless nights for many years to come....sorry about that! |
Richard
what a great and crazy hobby this is. We are running two very different air pump /tubing systems. Also our tonearms although they share some parts are more different in their construction and their setup requirements. We are using very different turntables, the amps, pre? and the most important thing - our rooms are different.
I'd say so far we are on par for the course like any other two audio guys/gals in this hobby ?
oh yeah.....and we are discussing the effects of changing out a length of air hose in the middle of all this stuff. Wonderful hobby.
There is one thing that stands out from your posts like a square peg in a round role to me. I run the same PSI with and without the damping trough, as designed by Bruce.
Its effects are real but subtle. Why are you not able to run the same psi without the trough ? I think you said the differences with and without are as high as 5 psi. Now understand I am not losing sleep over this - my kids give me enough reason for sleepless nights. something just doesn't jive. But as your arm is a customized, unique one, I don't really feel a need to understand why - was just curious.
That plus you don't just live down the street from me; if you know what I mean.
As long as you are happy....cool.
I have had my happy music lover's hat on for over 6 months.
If I choose to put on the audiophile hat one day again with vinyl, I can try tweaking with the air tubes as discussed.
The difference between MY two hats is that my music lover hat fits really well.
My audiophile hat for some strange reason has become a 1/2 size to small for me.
Happy Listening. |
Chris.
The config was not quite as you wrote.
In both iterations I used two regulators. The one in the compressor and a separate stand alone Norgren model.
Basically I slid the second regulator along a 43 foot length of clear soft PVC tube to position it either within 3 feet of the arm or 40 ft of the arm. This to test my theory that regulators themselves introduce tiny pressure perturbations which can be smoothed by the long run of flexible tube.
So, yes I believe that I have introduced a more consistent air delivery to the manifold. The key though for owners that have in-room regs close to the arm, is that the regs may be doing harm to the sound.
Note I made no change to the air supply circuit, just its configuration.
The pressure gauge is right next to the arm and I adjusted the second regulator pressure output such that the arm received the same pressure for the two configurations. So a spindle resonating problem would have shown up in both configurations. Further I know what excessive pressure sounds like and this was not what occurred last night.
The arm has a high pressure manifold. What actual design pressure? Don't know, but 17 to 18 psi with an oil trough works best.
Yes I tried different records and VTA settings. I did not remove the oil trough.
Findings were consistent across all the tests.
This would be very easy for you to try.
Just significantly increase the length of clear 1/4" PVC tube from the outlet of your in-room regulator to the arm. You will need to slightly (very slightly) increase the reg pressure to ensure that the arm sees the same input pressure due to a small line loss in the longer tube.
Now I know that this is not quite the same test as I did since you will be adding extra tubing but it will, I'm sure be informative.
Yep, I am well aware of the "better equals worse" scenario. Have gone down that dark alley many times.
Pretty sure that this is not one of those.
Their was no ambiguity at all with my findings in my rig.
Also just adding another finding from some years back.
The air stream needs to be earthed close to the arm. In my case, I earth the body of the pressure gauge which has a metal sensor that touches the air flow. Static build up?
cheers. |
thanks for sharing impressions Richard. With the regulator close, the soundstage shrunk both in width and depth. There is a subtle veil over the sound with attack and decay diminished. Just recollecting. When I was experimenting with PSI years ago, these are the same symptoms I encountered, when there was too much psi for the manifold and it caused the spindle to start resonating - affecting the cartridge. So out of pure curiosity my questions would be: 1)What PSI is your manifold designed for ? 2)Did you try different records that required different VTA's during the comparison ? 3)Did you try it with and without the damping trough. If you chose to compare again - I would go with a longer 6 foot section of tube to the arm and lower psi. Maybe I misunderstood what you were trying to compare so let me confirm. You went from this: pump--------40 feet hose-----tonearm manifold to this pump--------40 feet hose---regulator -----3 feet hose ---- tonearm manifold. If my crude flow chart is correct - you have imo introduced a more consistent air delivery into the manifold. The reason being alot can happen (changes)to the air in the 40 foot run. Here is something to think about. Sometimes when we introduce something that in theory should work better, for reasons described above, it ends up sounding worse. Well - what if better more consistent air delivery exposed a set up issue (i.e. too much psi) Again just thinking out loud - remote troubleshooting is difficult with a one sentence description. I do think its worth noting here again if anyone should pick up a used ET2 or ET2.5; and they do not know what PSI the manifold was set up for. One way to find out - put an old record on and start lowering pressure. When it starts skipping raise a few PSI. Fine tune final PSI by ear. ymmv - water deposits from the air could have clogged the capillaries requiring more PSI to even work ! The manifolds are easily cleaned - instructions in the manual. If I bought an Et2 from an unknown source I would clean them before setup. Cheers |
Ok
Since I cooked dinner tonite, I got a leave pass afterwards...,
Have just finished trying the second regulator close to the arm.
There was just 3 feet of tube between it and the arm, the original configuration having 40 feet of tube. I adjusted the pressure to compensate for line losses.
With the regulator close, the soundstage shrunk both in width and depth. There is a subtle veil over the sound with attack and decay diminished.
The model of regulator I use is. Norgren B07-201-A1KG.
Looks like a pretty standard unit and appears similar to the photos posted here by various owners.
After an hour of going back and forth to confirm my findings, I couldn't wait to settle back to the original layout.......
Compressor with built in regulator- 4 ft PVC tube- needle valve bleed off- second regulator- 40 ft PVC tube- pressure gauge- arm.
The Norgren regulator does something to the air flow that the arm doesn't like. Having 40 ft of tube mitigates this.
I would be curious to read findings from others where a significant length of soft PVC tube was used between the reg and arm vs a short length of the same tube.
For my setup the long tube was clearly superior. |
Chris.
Even if you use a joiner, you will still be removing one regulator from the air circuit so it will not be a true AB test.
Yep agree, measurements only take you so far.
We don't listen to numbers. |
don't think that your test is quite representative of what I was suggesting, since you are disabling one regulator but leaving its body in circuit. If their is any instability in the regulator it could be caused by the its structure, since the air flow path is convoluted. For example the water separator function is achieved by creating a vortex in the bowl. this is true Richard. not the best example - I could unplug both ends and just use a coupler. That said how accurate are the gauges we are using anyway? Even if these devices were perfect we know that no two records are identical. Always trust your own ears. Use measurement devices. PSI gauges, alignment devices, VTF scales to just get into the ball park. Fine tune with your ears. |
Chris.
You have now given us all another area to pine over. Humidity.....thanks a lot! :-)
I don't think that your test is quite representative of what I was suggesting, since you are disabling one regulator but leaving its body in circuit. If their is any instability in the regulator it could be caused by the its structure, since the air flow path is convoluted. For example the water separator function is achieved by creating a vortex in the bowl.
I will have a play this weekend where I move the regulator close to the arm, making the adjustment for line losses. This will keep the arm pressure the same.
I will use exactly the same hose and length so the only variable will be the reg position.
BTW, I have a pressure gauge very close to the arm, it reads in bar. Setting the pressure by ear results in a reading of 1.25 bar which is a little over 18 psi, not the 17 psi I mentioned earlier. That said how accurate are the gauges we are using anyway?
cheers.
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You can call this mad, or you can call this anal. So go ahead and call me mad or call me anal.......just pls don't call me Dorothy.....I am not worthy. |
RK - If this is correct then it may be better to have the regulator remote from the arm. A long length of soft hose to the arm then helping to smooth out the regulator pressure irregularities. Obviously more testing is required. One test would be to fit a surge tank after the regulator in a rig with a regulator close to the arm. Or simply add another long length of soft tube which would be so easy to do....Chris. Hi Richard - the extra in room regulator I use allows for AB testing of this at anytime. Long tube versus short going to the tonearm. All I have to do is open /disengage the in room regulator and it functions as a filter only, so in effect is a long tube to the pump. Let me explain something about my Timeter pump and it will make things more clear. From my experiences most pumps push air and the user is at the mercy of the environment as far as the quality of the air output goes. Meaning if the air has any moisture and particles, filters are needed to trap them. The ET tonearm's maker resides in Florida where it can get really humid. The ET 2.0, 2.5 tonearms if they had a choice would probably choose to live in Arizona; or in a room where there is forced air heating. They like the air dry ....very, very dry. My Timeter was designed for human use and has performance settings as far as how humid I choose to send air out at. Example: If you are in a room and want to be comfortable you would probably prefer air around 55-60 which is in the middle of the humidity scale to be really comfortable. The Timeter - with my T valve regulator at the pump (see pics on my virtual page) can be dialed down/tightened so that it exhales dry Arizona like air - even if the room it is in is at 80 % humidity. No other pump/compressor I am aware of does this and the ET 2.5 loves dry air. I have never seen a DROP of water in the in room regulator bulb other than the one time there was a blockage. Now the pump does need to work harder to produce moisture free air in a humid room. For three seasons late fall, winter, early spring the basement stays fairly dry with the natural gas heating. Once summer kicks in, it takes only 3 days for the basement to start feeling like a basement again - humid and damp. This is also the time when I make an adjustment to the Timeter by tightening down the regulator at pump's outlet so the performance gauge reads in the green zone. Green zone for this compressor/pump means the system is running efficiently and no moisture is being sent down the line. It expels the moisture like a car's AC at the bottom of the pump. It used to do 50 psi when new. It probably does around 45 now and I bought it used many years ago. With the in room regulator in engaged mode - I send down 21-22 psi from the pump and I steal 19 psi with the in room's regulator. So pressure drops at the arms location on purpose (Dover alluded to this in one of his posts) The excess air goes into the atmosphere beside the pump. So in fact I bleed out 25 + psi. I prefer to run with the in room regulator functioning as a regulator with the short run to the arm. It is I believe more precise and the long tubing just before it acts like a second, redundant surge tank in addition to the timeter's own built in surge tank . Redundancy is good. Remember I am in the business of contingency planning/risk mgmt - redundancy is ingrained in me. You can call this mad, or you can call this anal. The in room regulator is set for 19 psi. Along with being more precise/consistent, its bulb area also stabilizes the air (temperature) so it is same as in my room. Your average listening room goes up in temp as time goes by. Its important for the air imo going into the manifold being same temp as your room - just really dry. The in room regulator also gives me a visual of what is going on. Kind of like driving a car with real engine and radiator temperature gauges. I want to know what is going on. Sorry for the long post. Cheers |
Dover wrote:
".... Bruce goes through a design process, supported by principles of physics and sound engineering, includes mathematical modeling, the production of prototypes and thorough documented testing before his products go to market. There is no speculation or guesswork involved."
You say "I agree with Bruce's observations."
Please advise what testing you have done to arrive at that conclusion.
It should be verifiable engineering: no speculation, guesswork, or internet regurgitation will suffice. |
Richardkrebs, On the one hand you say that the air bearing is rigid at audio frequencies, but now you speculate that the arm is prone to chatter due to "pressure irregularities". You also claim that the pressure irregularities are audible. The two theories are mutually exclusive - they cannot both be true. 06-06-14: Richardkrebs
If there are pulsations in the air stream this will be manifest as slightly different flow rates into the manifold and thus pressures seen by each of these holes and the flow rate thru them. This would cause the spindle to chatter. You do Bruce Thigpen a disservice. 06-04-14: Richardkrebs
Below is a copy of a mail I received from Bruce T many months ago.
The resonance of the air cavity is over 500Khz and does not manifest itself on the surface of the bearing, it is a well damped liquid bearing.
I used three measurement methods when developing the tonearm, accelerometers, strain gages, and the simplest and most effective was the use of a second tonearm to play parts of the tonearm under test while playing a record. Please advise what testing you have done that would confirm your theory. The ET2 manual clearly states that Bruce goes through a design process, supported by principles of physics and sound engineering, includes mathematical modeling, the production of prototypes and thorough documented testing before his products go to market. There is no speculation or guesswork involved. The ET2 has evolved from the 1st incarnation that utilized low pressure low flow bearing, then with the advent of customers using higher pressure pumps ( the WISA300 for example) Bruce redesigned the bearing for high pressure low flow air supplies. Bruce will also custom build for specific air pumps and provide advice on cartridge compatibility with each of the options. It is abundantly clear that each bearing has an intended set of parameters with regard to pressure and flow. You have discarded the original ET manifold housing, discarded the decoupled counterweight, discarded the horizontal moving mass targets that the ET design is predicated upon, and may well be running a pump that is not optimised with your particular bearing. Unless you can provide some documented testing as Bruce does on his website, your comments can only be described as speculative at best. |
My thinking on why pressure irregularities have such a large effect is this. It is to do with the way the air enters the bearing manifold. This thru a small single hole. It then circulates around the sleeve and enters the 14, from memory, threaded and loosely plugged holes exiting around the spindle. Each bleed hole will see a slightly different inlet pressure because their is a dynamic flow around the manifold with associated pressure drops. If there are pulsations in the air stream this will be manifest as slightly different flow rates into the manifold and thus pressures seen by each of these holes and the flow rate thru them. This would cause the spindle to chatter. When I built the replacement manifold, I planned to interpose a finely sintered metal tube between the air inlet and the sleeve. The idea being to force the air to more approximately enter the sleeve area at all points simultaneously. I didn't do this because it made the diameter of the manifold too large and it would have fouled with the platter and I didn't think that it was a big deal. I do now.
The walker arm manifold has 4 air inlet points. Maybe they have looked at this issue and used multiple inlets to help reduce its effect. |
06-04-14: Richardkrebs
The arm IS rigid at audio frequencies, however it is sensitive to supply pressure irregularities. These are two completely different phenomena. Richardkrebs, your interpretation of Bruces email is interesting. Could you explain what you think happens when there are supply pressure irregularities. Conventional air bearing theory is that the dynamic stiffness of the bearing will be affected by the air pressure and the surface area of the bearing and other factors. Are you suggesting that the large diameter bearing tube upgrade and high pressure manifolds have no benefit and that users would be better off attending to supply pressure irregularities ? This would be a game changer for most participants on the thread if it were true. Are you using the 2.5 manifold and bearing tube or are you using the high pressure manifold on an ET2 ?? or are you using the original manifold on an ET2 ?? By the way, I agree with Bruce's observations - traditional tonearms with gimbal bearings are prone to chatter and noise, and the offset tracking angle introduces a raft of conflicting forces on both the cantilever and bearings. Notwithstanding that a unipivot is another story.. |
Dover
Below is a copy of a mail I received from Bruce T many months ago. You might find it enlightening reading.
"Richard,
The resonance of the air cavity is over 500Khz and does not manifest itself on the surface of the bearing, it is a well damped liquid bearing.
A statement - " the air gap allows movement at audio frequencies" - shows a lack of understanding regarding how a tonearm works.
In two out of three degrees of freedom (x,y, & z axis) a cartridge is completely free to move in any tonearm. How can it not move in the X & Y axis but magically pull and push in the constrained Z axis? The record is encoded in and the forcing functions greatest in the X (vertical) and Y (horizontal) axis.
A tonearm works because of mass present in all three axis with the forcing functions above the systems natural frequency. The tonearm components headshell, arm wand, are thousands of times heavier than the cantilever and stylus, so by a ratio of masses, they sit still.
To put this in perspective go run back and forth and jump up and down on a several hundred thousand pound untethered barge and watch the displacement of the barge, while it will move, its motion will be extremely small relative to yours and proportional to the ratio of masses.
I used three measurement methods when developing the tonearm, accelerometers, strain gages, and the simplest and most effective was the use of a second tonearm to play parts of the tonearm under test while playing a record. Measurements at the air bearing are more than 60dB (1 million times) below signal levels, lower than the pivoted tonearms I used for comparison. In reality the ET-2 has its highest inertia in the Z axis and appears rigid to the cartridge.
If a tonearm moved at audio frequencies it would reveal itself as dips in frequency response.
brucet"
The arm IS rigid at audio frequencies, however it is sensitive to supply pressure irregularities. These are two completely different phenomena.
re pressures. In my rig, I found 12 PSI to be optimum without an oil trough, 17 psi with one. There is no inconsistency.
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Richardkrebs,
From your explanation I conclude that you are putting an argument forward that the more components that are in the process that are inherently unstable, then based on mathematical probability you are suggesting that this may increase the efficacy of the air flow. You might like to research chaos theory. Another solution may be to use a rigid tube, but put lots of pins through the tube - if you do the calculations and modelling, it would be possible to have a totally chaotic air flow rather than patterns of eddies, which may be preferable.
Last year you said that the ET2 air bearing is rigid. I assume since you now claim that you can hear a difference with different pumps and air supply configurations, that you would now concede that the air bearing is not rigid.
I have studied engineering including fluid dynamics and the way I view the ET2 is that the air bearing is not rigid, and what you are doing with all this experimenting on air pumps and tubing is in fact minimising instability within the bearing. That is why you hear a difference.
I note that you are now running 17psi whereas previously you said that 12psi was optimum ( and that your arm was perfectly rigid ). Can you explain why you have changed your view. Have you removed the lead and put your arm back to standard with the decoupled counterweight put back in now ? |
The motivation for putting a soft tube between the two regulators was the finding that a small amount of bleed off between the regulators had a positive effect. This implied that the air pressure was not constant between the regulators. Or for that matter after the last regulator. More pressure equals more flow into the arm since it is not a compensated load and since a needle valve is not a compensated load either it will pass more or less air as the pressure increases or decreases. So the needle valve tends to smooth these pressure changes hence smooth out the air flow.
The soft walled tube acts slightly like a balloon, it tends to absorb small pressure perturbations by expanding with increased pressure. The surprising finding was that this positive effect was present even when the pump had turned off. This points towards the regulators themselves creating tiny pressure changes which the softer tube helped to reduce. Acting in a way like a surge tank.
If this is correct then it may be better to have the regulator remote from the arm. A long length of soft hose to the arm then helping to smooth out the regulator pressure irregularities. Obviously more testing is required. One test would be to fit a surge tank after the regulator in a rig with a regulator close to the arm. Or simply add another long length of soft tube which would be so easy to do....Chris. A small increase in regulator pressure may be required if this was done to compensate for the line losses.
It is fascinating stuff.
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Very interesting, Dover. Thanks for the explanations and music recs.
Regards. |
Frogman et al,
There are many reasons why different tubes will affect the sound.
Depending upon the velocity, the air is likely to flow chaotically, forming vortexes and eddies as it moves down the pipe, it is not necessarily laminar.
The geometry of the tube, the roughness of the tube walls, the elasticity of the tube and the purity of the air all affect flow and chaotic behaviour.
Furthermore, air is compressible, which affects flow. And finally as air flows, compresses or decompresses, it can change temperature which affects pressure and therefore flow.
Keeping the tube as straight as possible will reduce turbulence, just like an optical cable with digital - oh the irony.
It is quite complex.
As an aside I would have thought it would be advantageous to have a regulator at the end of the long tube, just prior to the arm, as the length of tube after the regulator will, if my rusty memory on fluid dynamics is working, drop the flow rate going into the bearing.
In other words if 2 of you had the same regulator and 40ft of tube, and one places the regulator at the start of the tube, and the other places the regulator at the end of the tube, then I would expect that you would end up with different flow rates into the bearing. I would at the very least expect a significant impact on the "sound" from where you position the final regulator in relation to the arm bearing.
Suggested music for AB testing - JS Bach Air on the G String : Zoltan Rozsnyai/Philharmonia Hungarica on M&K Realtime for the audiophiles, perhaps Malcolm Sargent/New Symphony Orchestra for the purists on HMV ( 78rpm of course ). |
Chris, thanks for the links. A very important topic and one that is not understood by many music consumers. Music is such a personal thing for most of us ("Those eyes!") that it causes most listeners to think of themselves as music lovers vs the more clinical "consumer". In fact, music is a product like any other, and it's creators are entitled to fair compensation for its consumption. I have never understood why many feel a sense of entitlement to essentially steal that product; no different than shoplifting. I remember well when the SNL band had to pull all the charts of Beatles tunes out of our book because it was simply too expensive to perform them. As with most things, what is ultimately paid is negotiable; and, The Beatles, being The Beatles, have no incentive to negotiate anything. It may seem unfortunate, but I say more power to them. |
Richard and Chris, I have always had a 50' spool of excess (unnecessary; length-wise) clear and fairly rigid tubing between the pump and my surge tank. Like Chris mentioned, the coil of tubing will act as a surge tank. I was able to confirm the benefits of doing this when my previous surge tank exploded and I needed something in the interim.
I am intrigued by the comments re soft vs rigid tubing. I have not experimented with the two versions and logic seems to suggest that rigid would be better as Chris says. However, might it be possible that the air pressure causes the soft tubing to expand and actually create an effectively wider-diameter tube, thus increasing the "surge tank effect"; and, why the soft/clear sounded better?
Like someone recently said, this is mad-scientist territory. |
Richard - I was thinking about what you posted. If using a run of 40 feet, there is enough "space" within that tubing to allow the tubing to act like a surge tank when used with a regulator at the other end. This was explained to me years ago by the shop where I got my fittings. When the tubing material is soft there is also a greater chance that the tubing will expand and contract to deal with changes in temp/humidity and the air supply. If you have a regulator at the end of it "prior" to the tonearm you can regulate it and thus the surge tank analogy. You don't need 40 feet of actual house space to get these benefits. You can just coil up the tubing in an area.
Now some I have known choose to have long runs, straight in to the tonearm manifold, meaning the tonearm air bearing spindle could be experiencing air flow changes as the record plays. Especially if the air source is not steady or in a different part of the house; different temp, humidity etc. I imagine this can make for some interesting music ?
I am using fairly rigid white poly for the main run to the in room regulator. Its a perilous journey around corners and through a wall. Its quite stiff and rigid, it won't kink and is very easy to feed through tight areas. Its the same tube material they use in house town water 3/4 inch plumbing with sharkbite connections. Its doesn't expand and contract with temperature/humidity changes. The short run from the in room regulator to the tonearm is clear tubing. Cheers |
The eyes have it Frogman. Also one very classy lady Shirley Horn. Truth is that in many ways they have always had the power and control. If I can add an observation. In regards to business power positions, my work field - IT Business Services, is one of those areas that has many women in the key power positions. I can honestly say the best bosses (fair and understanding) I have worked for, have been women. As consultants we worked for a number of women at companies who were our "boss" during engagements. One of the more interesting ladies I still remember well as we did a job for the IT shop at her organization. SOCAN (the Society of Composers, Authors and Music Publishers of Canada) Among the many facets of this company, their IT shop runs the actual computers that figure out and calculate which artists get paid performance royalties based on air play. A fascinating stint for me as a music lover and this lady boss we worked with was very colorful. If anyone has ever been curious to learn how the heck they figure out how an artist gets paid royalties for their music played on the air, here is a short animated introduction to it - from the SOCAN site. http://www.youtube.com/watch?v=0IJB6X-OGec |
Further to the quality of the air supply.
My current air rig is.. Compressor with storage tank and built in regulator.. 4 feet of 1/4" tube, tee to bleed off needle valve and second regulator with filter/water trap.. 40 feet, soft clear PVC 1/4 " tube....arm.
Compressor cycles off at preset pressure.
The 4 foot tube was black hard plastic. What type of plastic? I don't know. I have just changed it to 1/4" PVC soft clear plastic.
Testing with the compressor cycled off showed an improvement with the clear PVC. This was a little surprising to me so as a backup I inlisted one of my sons to do an ABAB test.
I just asked him to tell me if he could hear a difference and if yes, which he preferred and why. He did not know what change I was making.
Note as above. The compressor pump had cycled off for these tests so the air was being drawn from the tank only.
He told me that he could hear a difference and he preferred the soft PVC. Stating it is "much clearer"
Regulator instability?
Go figure! |
Richard, glad you enjoyed the tracks. Chris, times truly have changed; but, maybe it's all just less subtle now. Truth is that in many ways they have always had the power and control. They can turn us into mush with a look from those Beth Hart eyes. They have what we want; the "fire". More Beth Hart (those eyes!): http://m.youtube.com/watch?v=fALdOkf_eCMWifes, if you're sneaking around here, this one's for you (and don't be too hard on us). One the greatest singers of all time: http://m.youtube.com/watch?v=K-mI3k6YIFMand one of the most beautiful and, in its way, sexiest records ever: http://m.youtube.com/watch?v=7OtpZe_HSNg |
Frogman your Beth Hart & Joe Bonamassa videos had me looking for something to mix with my morning coffee (...and maybe a cigarette?)
only to find my liquor cabinet has been pillaged.
The Nancy Wilson video sure harken's back to a much simpler time imo - boy, times have changed.
I tell my 19 year old son, "the girls never approached you in clubs when I was your age"; "the guy had to have a plan and a good introduction to go up and approach a girl in a club". He doesn't believe me, as these days according to him, the woman have become the hunters. I wish I was 19 again. |
Frogman
I enjoyed the tracks very much.
Thank you! |
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Frogman can you provide us with a music selection that in your opinion exemplifies this... I'll bet there's some passion for music there! Jazz, in particular. Huh, you say? Look up the original meaning of the word as used by musicians :-) I am in big, big doo doo if my wife ever find this thread. |
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I'll bet there's some passion for music there! Jazz, in particular. Huh, you say? Look up the original meaning of the word as used by musicians :-) could this be the other thing I think of, other than running, :^) when I see Dorothy ? |
I was kind of dreading any responses but was ultimately disappointed that there were really no responses. Slaw to add to Richard and Frogman's comments. imo - It is always better to give than to receive. Meaning rewarding - gut feel stuff. You gave "the gift" as far as this hobby is concerned to me. Music that touched you and you put it out there. IMO - you can't get more personal and giving to others than this in this hobby. Never expect anything back. I hope to see more recommendations from you. The marker you gave 'O'(I can't duplicate it), followed by mad scientists, ..... Copy and paste from Harold's post. `Ö´ In Windows: Start>>All Programs>>Accessories>>System Tools>>Character Map (Sometimes called 'Keyboard Map') select characters from different languages. ^Ö^ I changed it up. can't find the marks on either end that Harold used ? |
