Hi guys, a classic Air Tangent on AudiogoN: http://app.audiogon.com/listings/tonearms-nos-air-tangent-tonearm-linear-air-bearing-tonearm-2013-11-12-analog-29732
Is there anyone who has experienced an AT ? Frankly, I was searching for it and a Forsell 5 years ago (I didn´t know ET-2´s excistence at the time) but I suddenly found the Trans-Fi arm and bought that immediately... and saved a fortune ;). It has proved to be the very best audio bargain in my history. The ET-2 is another very interesting tone arm though.
Dave G, have you got an ET-2 already ? |
Keep in mind that all the cartridges you own are fairly high compliance; including the VDH which is high compliance by MC standards. The "base aluminum arm wand" is well suited to higher compliance cartridges. Most MC's are lower compliance which means they will send more energy into the arm wand; a higher mass wand such as the magnesium wand would be a better match for most MC's.
Having said that, I have gotten excellent results with my ET2 (magnesium wand) and a Shelter 901. The Shelter's stated .5 mv output plays considerably louder than my VDH's stated .65 mv. It is dynamic, robust and full sounding with a richer and more romantic tonal quality than the VDH's which leans toward a whitish/gray tonal quality (in my set-up, of course). Definitely worth trying. |
Okay, guys, how 'bout some MC cartridge recommendations for mating with my ET Two. I'm currently using my tried-and- true van den Hul MC Two HOMC (2.25mV output with vdH 1 stylus). I really like the sound of this cartridge with the ET Two (transparent, fast, dynamic, and ballsy) and the vdH 1 stylus is the quietest in the groove of any stylus I own and is claimed to last for 3000+ hours. Just testing the waters to see what is out there that would be better. My requirements are: 1. must be an excellent match for the ET Two with the base aluminum armwand 2. 0.5mV or greater output (.65mV or higher would be preferable) 3. cartridge weight <10g (the lighter the better) 4. selling price <$2k 5. <250 hours if used or freshly retipped/refurbished 6. must sound significantly better than my vdH MC Two (this cartridge is tragically under-publicized and under-rated IMO) I listen mainly to acoustic jazz, blues, rock, and a little classical. You can see associated equipment in my "System" link. I have been eyeing a Colibri XCP HO for sale here on Agon right now: https://app.audiogon.com/listings/cartridges-van-den-hul-colibri-high-output-as-new-excellent-condition-2013-11-17-analog-NetherlandsThis one meets all of the above criteria, but I am a little spooked of the Colibri due to some horror stories I have heard about its fragility and quality problems with recent vdH retips/rebuilds, plus I can find nothing on the web about it's compatibility with the ET Two or similar air bearing arm. If I can't find something that meets all of my criteria, I will just stay with the MC Two, which is probably what I should do anyway ;^). PS: I also have a nice stable of MMs: Empire 4000D/III, Signet TK-7LCa, Sonus Gold Blue, Micro Acoustics 530mp and 2002e, Astatic MF200, ADC XLM II Improved, and Shure V15 Type III MR. I read that some of you have liked the Empire with the ET Two. Is that still your opinion? What about the others? Dave |
Another hint (when no arm wand is visible):
Look at the width of the portion of the manifold housing (where the lettering is printed) that extends beyond either side of the length-wise "edge" of the spindle tube. Or, look at the same "edges" in relation to the lettering on the manifold housing. Either way, which tube's diameter is wider will be obvious. |
Welcome to the thread Banquo... touchee!
Firstly - I am not certain of the answer myself (well it would be a guess) based on pictures themselves, especially when just one ET2 is shown.
Frogman is able to tell the difference from pictures. I think he is using the armtube as a reference ?
But the picture I posted shows only two manifolds and spindles only - no armtube.
Pictures are an illusion (sort of like this hobby?) of camera angles and scale.
imo - this is very similar to fishing, in that if a fisherman wants their fish to look bigger in the picture - they hold it out "in front" instead of to the side of them to show proper scale.
Of the two shots that are in that pic of my last post.
Here is a hint.
One of them is smaller in scale ?
Yet the spindle still appears to be the same size as the other one ?
For non-ET2 owners following the thread the answer should be clearer ?
|
But, Chris, you should know that if I ever have a question about the ET arms, I would ask you. So asking me to identify one is like asking yourself ;). |
Oh, wait! You said non–ET users. Sorry. |
Too easy. I will let the others chime in :-) |
does another audio product exist - that in pictures is so easy to mistake I ask ? I guess I really meant to say "tonearm" instead of audio product :^) Skill testing question - this is for non ET2, ET2.5 owners only. Halcro? Nikola? DG ? Lew? Banquo363, Timeltel ......... Syntax... I am calling out to you too....all others? In this picture which is the 2.5 and why ? http://cgim.audiogon.com/i/vs/i/f/1384998156.jpg |
Hi Frogman - it does look like an ET2 to me - but I took my reference from their website directly. Mikro Seiki RX-1500 FVG turntable with three arms and cartridges that were, SME V arm and Dynavector XV-1S Ruby, ET2.5 arm and Dynavector XV-1T, Zeta arm and Kiseki Purpleheart Sapphire. The HP 2 is sometimes mistakenly referred to as a 2.5 Oh I agree - and does another audio product exist - that in pictures is so easy to mistake I ask ? In person they are very clear. |
Chris, this pertains to an earlier discussion about identifying a 2 vs a 2.5. Look closely at the pictures of the ET. I would bet one of my extra arm wands :-) that its a 2 not a 2.5. The HP 2 is sometimes mistakenly referred to as a 2.5. Regards. |
from the Audiophile Club of Athens. A very interesting website with a lot of audio passion like here at Audiogon. I came across a recent visit with a member with an ET 2.5 on a Micro Seiki table. He also has an SME V and ZETA tonearm on the same table. To see the ET 2.5 in action for a bit, scroll to the bottom of the page for the video. http://www.aca.gr/index/meetings?row=2320to Kyriakos (owner of the ET 2.5) If by chance you happen to visit Audiogon, please stop by and say Hi to us here ! Cheers |
Hi Dave - I am looking forward to your impressions of the ET 2.0 HP manifold. Cheers Chris |
Hi guys,
I talked with Bruce yesterday. My 2.0 HP manifold is two weeks off. There are no 2.5 manifolds nor setup jigs available right now, but there are tentative plans to make a production run of both in the next 6 months or so. Bruce confirmed that the 2.0 HP manifold is a better match for medium/high compliance cartridges and the 2.5 is a better match for low compliance carts (difference in horizontal effective mass with the 2.5 being heavier as noted previously in this thread).
We discussed the topic of air pressure and air escape. My interpretation of the conversation is that it is normal to be able to hear some amount of air escaping from the bearing and also to be able to hear a low-level air noise at high volume with your ear to the speaker (Chris's pump test). The amount of air escaping and thus the audibility will increase with higher air pressure for a given bearing clearance, consistent with my experience.
After extended listening comparisons, some including my golden eared wife, I have decided that changes in air pressure are audible (similar in scale to VTA changes) and our preference changed with the recording. Keep in mind that this is with the stock 2.0 manifold. Some instruments within the soundstage move forward at higher pressures, creating a better delineated front-to-back separation, but the overall sound is less relaxed and natural, with a change for the worse in tonal balance, particularly on piano. Ended up back at 3.6 psi (at the arm) for best overall performance with the stock manifold. Bruce has said this to me consistently over the years and, being the hard-head that I am, I had to prove it for myself and finally have the proper quality and control of the air system to feel confident in this conclusion.
As always, this is MY preference in MY system and YMMV. I feel certain that all this will change with the introduction of the HP manifold, where the smaller orifices and tighter bearing/spindle clearance will eliminate the downsides described above at higher pressures and further enhance dynamics, bass performance and soundstaging as Frogman describes.
Dave |
Chris, thanks for Bruce's comments. It all makes complete sense, however my question is still not answered. I suppose its academic, but as a point of interest, I fail to see how air would NOT escape regardless of pressure. Air (like water) under any amount of pressue will choose the path of least resistance, so even though the air delivered at the "ideal" pressure will "surround the spindle 360 degrees", some air will still escape out of either end of the spindle; there is no gasket or blockage to stop it.
Re Dave's comment about air bearing stiffness: with my HP 2.0 bearing and Wisa pump, if I push on the spindle sideways, it takes very little force to cause the spindle to rub inside the manifold. With the Medo delivering 17-19 psi at the arm (yes, it will do that), it takes a considerable amount of sideways force to cause it to rub. The bearing is MUCH stiffer with the Medo, with a resulting major improvement in sound; particularly in the areas of dynamics, bass tautness and speed, and soundstage detail and stability. |
Chris, Trans-Fi needs only a 4 psi aquarium pump, smoothing tank(s), and a good brass needle regulator. No need for an evaporator tank, given the small 2-3 psi differential between the pump and the tonearm. One may be tempted to think of it as a poor man's solution, however in my view its design has fewer problems to solve than a captured air bearing and illustrates the virtue of KISS. |
I would think that the favorable qualities of a captured air bearing in this application are maximum bearing stiffness(a function of air pressure) and minimal air turbulence(a function of air velocity through the bearing and surface friction.) The best one should have the tightest clearance in order to minimize air loss and turbulence attendant with velocity.
In contrast, the stability of the Trans-Fi bearing is not a function of stiffness, but rather of aerodynamic balance. It functions like a glider wing that requires only the minimal air pressure and flow to obtain lift. It operates in a horizontal plane, rather than in 360 degrees as with a captured air bearing. The air velocity through the bearing is higher than with captured air bearing, but as air pressure is low, turbulence is minimized. In this particular instance, the more pressure, the higher the lift, the sloppier the bearing. |
Frogman - Someone explain to me how in a "captured air" bearing design air will NOT escape regardless of the pressure delivered to it. I think that when we talk about being able to hear it, it is simply that, the point at which it becomes audible; not that there is no air escaping prior to that point. Frogman - I remember talking to Bruce about this some years ago. I sent him an email and also confirmed things in a call this morning. The ET2, ET 2.5 is a captured air bearing system meaning "Air surrounds the spindle in a circle 360 degrees" I did ask him about the type of air bearing tonearm that uses a cup bearing which is floated. We did not reference the Trans Fi or other tonearm just the type of design. - his response to me on the phone- the more air and it will become floppy. So just enough air to float is required - supporting what Dave G said. ************************************************* Some more information - this was from my actual email - his response in quotations. Hello Bruce I have two general questions. If we use my ET 2.5 as an example that you set up for 19 psi. 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) "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." If someone has a 20 year old stock ET2 designed for about 3 psi and decides to pump in 15 psi. The extra air will just escape around the edges of the manifold and at a rate that can be heard ? "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. " ********************************************* Bruce really like the idea of the pump test. I then asked him about all the ET2's on ebay and other sites that people are buying used - many come with no pumps. His advice was to start low with them 3 psi and go up. Whatever PSI it takes to float the spindle properly and work is the PSI that should be used. A case in point my ET 2.5 is designed for 19 psi. I told him if I start lowering the PSI it will start mistracking a few PSI below that. He confirmed this and this is by design. |
Dgarretson - The air pressure at this threshold depends on the weight of the selected wand and counterweights. Dave G - thanks for that interesting info re: Trans Fi tonearm. Would it be correct to assume an owner of a Transfi needs a pump that is variable in its PSI for the different arm wands and cartridges ? With the ET2, ET 2.5 one psi is used it does not change as the Spindle/Manifold remains the same. Different armwands and I Beam adjustments - single, double, triple springs are made for the different cartridges. yes two very different designs. |
Been thinking about the "air escaping" issue. Seems to me that what has not been made clear enough is that there will be air escaping no matter what the pressure is. While it is obviously true that an air bearing will be optimized for a specific pressure range beyond which some of the mentioned issues concerning resonance may occur, we also know that dealing with resonance is a tricky issue and a bit of a black art which involves the rest of the system (specific cartridge and its resonance characteristics, and even things like how much torque one uses to tighten the adjustment bolts on the arm). Clearly, there will be a point when too much, or too little pressure, will be simply too much/little, but I believe that there is a fairly wide range beyond the "design ideal" which is "system" dependent and which, as always, is determined by what simply sounds best.
Someone explain to me how in a "captured air" bearing design air will NOT escape regardless of the pressure delivered to it. I think that when we talk about being able to hear it, it is simply that, the point at which it becomes audible; not that there is no air escaping prior to that point. |
To clarify, I mean to say that at LOW pressures approaching the threshold of mistracking, the bass comes up and musical presence improves. |
Chris, the manufacturer recommends lowering air pressure of Trans-Fi to the point that the needle skips backward a groove, then slightly increase pressure to restore tracking. The air pressure at this threshold depends on the weight of the selected wand and counterweights. One owner with a very light wand and counterweight set-up reports running below .25 psi. I'm currently using a heavier custom wand with dual front and rear counterweights and a CF sled that together "float" at around 1.25 psi.
Similar to what I gather is the case for ET, with the stylus resting on a stationary record, a rumbling through the speakers increases slightly with rising air pressure. This effect is never at a detectable level with music playing. However, at pressures approaching the threshold of mistracking the bass comes up and musical presence improves. |
Is there significant air coming from the manifold where the spindle enters and exits? You will feel the air coming out with your finger near both ends.
NONE DETECTABLE AT ~3PSI BUT DEFINITELY FEEL AIR ESCAPING AT EITHER END OF THE BEARING HOUSING AT 7+psi - MORE AS AIR PRESSURE IS INCREASED, BUT NO "KICKBACK" OF ARM AT END OF TRAVEL AS OTHERS HAVE REPORTED. Dave - 7 psi is over twice what the stock ET2 design calls for. So your arm is indeed working well - imo. Bruce offers two upgrade options unless things have changed. You send him your stock ET2 manifold and spindle and he can do one of two things. upgrades it to 1) an ET2 HP manifold model or 2) ET 2.5 with the bigger spindle. Something to consider - he can also make the air plug inlet point up or down. As Frogman, I look forward to your impressions of the HP manifold whether as a ET2 or ET2.5 HP model. Cheers Chris |
Dgarretson - With this design the lowest possible air pressure that floats the bearing(about 1 psi)sounds best. DG - I am curious - is the 1 psi the recommended manufacturer psi? How high a PSI have you experimented with and how were the sonics affected on the Transfi arm ? thanks |
****Doubtless the effect can be mitigated by reducing air gap tolerance****
That is precisely what the HP bearing/manifold does. Point well taken, however. I will say that after using the regular non-HP bearing with the "higher" pressure Wisa for a few years (before getting the HP) I experienced no damage traceable to this issue.
Re the "different approach":
The Forsell (which still sits in its boxes waiting) uses the low pressure/non-captured bearing approach. Will report when I get around to setting it up. |
Air escaping from the bearing can cause subtler damage by modulating the arm wand and stylus. This may be a necessary evil in any air bearing design... Doubtless the effect can be mitigated by reducing air gap tolerance or with arm wand damping. I suspect that the Kumza Airline has a particularly close gap, as it is designed for higher pressure 60 psi operation. At CES I asked F. Kumza about this. He replied that as the technology is well proven in industrial instruments in microscopic applications, it should be good enough for audio.
Trans-Fi/Ladegaard is the only air tonearm that I know of that doesn't use a captured air bearing. Air escapes freely all around the bearing. With this design the lowest possible air pressure that floats the bearing(about 1 psi)sounds best. A different approach. |
Re "escaping air". Even with the HP bearing/manifold there will be air escaping from the ends of the bearing. In my case you hear it only when the arm is at either end of its "trajectory"; and certainly cannot be heard when music is playing. IOW, you hear the air when it escapes and then has either the rear end cap or front elbow to make contact with. In general, the sound of a small amount of air escaping is normal, subtle, and should not be surprising. Chris is correct about the issue of pressure at the pump vs that at the arm, but the Medo 0910 is conservatively rated and actually outputs closer to 30 psi, so achieving 17-19 at the arm should not be difficult. Dave, you will be very pleased with the HP manifold and Medo; it is not a subtle difference. Keep us posted. |
HI CHRIS - ANSWERS IN CAPITALS BELOW:
Dave - just so we understand.
so no noise in your system with NO pump on - stylus in groove - and the preamp volume high. RIGHT
this is with a stock ET2 which is designed to work at about 3 psi. RIGHT
When you turn the pump on there is no noise in your midrange driver up to 3.5 psi, RIGHT
So we can assume the ET2 with your pump works well to 3.5 as designed ? YES
In fact it is quiet to just under 5 psi. So all is good.
but at 5 psi you start to hear what sounds like air (like tube rush) in your midrange driver. YES
It is not a mechanical piston type noise, or drone like noise - it is the sound of air - maybe like air escaping ?
NOT MECHANICAL OR PISTON NOISE OR DRONING, JUST THE SOUND OF AIR, LIKE AIR ESCAPING. SIMILAR TO THE AIR SOUND YOU HEAR WHEN INFLATING CAR TIRES FROM AN AIR TANK WITH NO COMPRESSOR, BUT SOFTER.
It gets louder to 7 psi and then stays the same to 17 psi. RIGHT. MAYBE SLIGHTLY LOUDER AS PRESSURE IS INCREASED.
try something - with your system on mute and the ET2 raised and at rest.
crank the PSI up all the way to 21 and put your ear right next to the ET2 manifold- do u hear any sounds like a balloon with a leak ?
DID THIS AND FOUND OUT THAT THE AIR INLET NOZZLE WAS LOOSE WHERE IT SCREWS INTO THE ARM HOUSING. HAD TO TURN IT 180 DEGREES TO TIGHTEN. NOW AIRLINE FORMS A U-CURVE BETWEEN ARMBOARD HOLE AND INLET NIPPLE. LOOKS FUNNY BUT WORKS. NO MORE AIR LEAK THERE. WILL ASK BRUCE ABOUT THIS.
If yes is there air coming from a bolt ?
I STILL HEAR A VERY,VERY FAINT AIR NOISE FROM AROUND THE BEARING AREA. TIGHTENED BOTTOM VTA ADJUSTMENT BOLTS TO SEE IF ANY EFFECT , BUT NONE. CHECKED OTHER BOLTS QUICKLY. I BELIEVE THE REMAINING AIR NOISE IS COMING FROM THE BEARING ITSELF, BUT IMPOSSIBLE TO TELL FOR SURE.
Try wiggling the tube at the input nozzle around. It would be shame if a great pump system and that connection at the plug is not tight. If there is a leak at the plug - pull the plastic out - cut an inch off so the plastic is tight and fresh - re-insert. TUBE WAS TIGHT BUT NOZZLE WAS LOOSE - SEE ABOVE.
Is there significant air coming from the manifold where the spindle enters and exits? You will feel the air coming out with your finger near both ends. NONE DETECTABLE AT ~3PSI BUT DEFINITELY FEEL AIR ESCAPING AT EITHER END OF THE BEARING HOUSING AT 7+psi - MORE AS AIR PRESSURE IS INCREASED, BUT NO "KICKBACK" OF ARM AT END OF TRAVEL AS OTHERS HAVE REPORTED.
With the info you provided it sounds to me like the HP manifold would fix this as its lungs are designed to inhale the higher PSI. SURE HOPE SO!
Frogman uses the 0910 and says that it does a great job with this HP 2.0 bearing at 17psi.
Frogman provides clear support for the HP ET2 model with the same pump.
It is very easy to spend other peoples money :^)
FROGMAN IS AWESOME!
Since you are hearing benefits of the higher pressure - but you have a stock ET2 it makes sense to me to do it, if you feel its worth it? Bruce charges a reasonable amount for both upgrades ? Making the ET2 HP or by using his magic to transform the ET 2.0 into the 2.5 HP. As you said this would take a few weeks. I WILL CALL BRUCE TOMORROW TO CONFIRM THAT MY ORDER IS STILL IN QUEUE. SURE WOULD BE GREAT IF HE MAGICALLY FOUND A 2.5 BEARING ;^)
Some input from the others?
I recently called VPI about the leakage issue and they sent me some modified round rubber bushings to place around the outside of the schrader valve so that it seals the metal cap to the corner pods. Seems to be working great so far.
What a great service company. I bet they didn't charge you for those either, and if they did a very nominal charge.
THEY CHARGED $2.50 FOR A SET OF FOUR. ALSO GOT NICE PLUGS TO FILL THE HOLES IN THE TNT'S PLINTH WHERE THE TRI-PULLEYS WERE FOR $5 EACH.
I saw a set on "that auction site" for 400 bills. They show some deformation on the top. For that price, I would want an audible improvement over the air bladders in addition to eliminating the aggravation of maintaining level. Any opinion on that?
http://www.ebay.ca/itm/Audio-Technica-AT616-Pneumatic-Suspension-Audio-Insulator-4-pcs-/321244326789
THAT'S THEM
Probably 500 by the time they get to you.
I don't know what to say - everything in this crazy hobby just keeps going up in price.
What you see in the picture may be marks only and not an actual indent.
The seller can verify this.
Sounds like your VPI fix is working so I would hold off. I'd put money into the manifold ? RIGHT. MAYBE ALSO A NEW AUDIO NOTE WIRE LOOM PER FROGMAN. MY AYRE PHONOLINEPREAMP HAS XLR INPUTS FOR THE PHONO STAGE. WOULD LIKE TO GET THE BENEFIT OF THE DIFFERENTIALLY BALANCED CIRCUITRY AND ELIMINATE THE RCA TO XLR ADAPTERS I AM USING NOW AS WELL AS THE ARMWAND PLUG, ET RCA JACKS AND INTERCONNECTS (ALTHOUGH THEY ARE VERY GOOD ONES).
THANKS CHRIS! MUCH APPRECIATED.
DAVE |
Any suggestions on how to reduce/eliminate this (may be solved with the HP manifold)? Dave - just so we understand. so no noise in your system with NO pump on - stylus in groove - and the preamp volume high. this is with a stock ET2 which is designed to work at about 3 psi. When you turn the pump on there is no noise in your midrange driver up to 3.5 psi, So we can assume the ET2 with your pump works well to 3.5 as designed ? In fact it is quiet to just under 5 psi. So all is good. but at 5 psi you start to hear what sounds like air (like tube rush) in your midrange driver. It is not a mechanical piston type noise, or drone like noise - it is the sound of air - maybe like air escaping ? It gets louder to 7 psi and then stays the same to 17 psi. I would think if it was mechanical / piston problem it would maybe be heard at the lower pressure too. Maybe the hydraulic guys? can chime in - Richard ? try something - with your system on mute and the ET2 raised and at rest. crank the PSI up all the way to 21 and put your ear right next to the ET2 manifold- do u hear any sounds like a balloon with a leak ? If yes is there air coming from a bolt ? Try wiggling the tube at the input nozzle around. It would be shame if a great pump system and that connection at the plug is not tight. If there is a leak at the plug - pull the plastic out - cut an inch off so the plastic is tight and fresh - re-insert. Is there significant air coming from the manifold where the spindle enters and exits? You will feel the air coming out with your finger near both ends. With the info you provided it sounds to me like the HP manifold would fix this as its lungs are designed to inhale the higher PSI. Frogman uses the 0910 and says that it does a great job with this HP 2.0 bearing at 17psi. Frogman provides clear support for the HP ET2 model with the same pump. It is very easy to spend other peoples money :^) Since you are hearing benefits of the higher pressure - but you have a stock ET2 it makes sense to me to do it, if you feel its worth it? Bruce charges a reasonable amount for both upgrades ? Making the ET2 HP or by using his magic to transform the ET 2.0 into the 2.5 HP. As you said this would take a few weeks. Some input from the others? I recently called VPI about the leakage issue and they sent me some modified round rubber bushings to place around the outside of the schrader valve so that it seals the metal cap to the corner pods. Seems to be working great so far. What a great service company. I bet they didn't charge you for those either, and if they did a very nominal charge. I saw a set on "that auction site" for 400 bills. They show some deformation on the top. For that price, I would want an audible improvement over the air bladders in addition to eliminating the aggravation of maintaining level. Any opinion on that? http://www.ebay.ca/itm/Audio-Technica-AT616-Pneumatic-Suspension-Audio-Insulator-4-pcs-/321244326789Probably 500 by the time they get to you. I don't know what to say - everything in this crazy hobby just keeps going up in price. What you see in the picture may be marks only and not an actual indent. The seller can verify this. Sounds like your VPI fix is working so I would hold off. I'd put money into the manifold ? Chris |
Hi Chris,
Thank you so much for the comprehensive response. Very helpful.
I shamelessly stole the TNT thread drive mod (all the way down to using unwaxed dental floss) from your posts here. BIG improvement!
Ditto for the second low pressure regulator that I installed behind the table (stole it from your posts). There is only 2 feet of 1/8" tubing and a check valve between this regulator and the arm, so all pressures quoted in my posts are essentially "at the arm".
My compressor is the Medo AC0910. Compared to the AC0110, the 0910 puts out a lot more air volume at higher pressures and has a higher max operating pressure (21.4psi vs 17.1psi for the 0110). Frogman uses the 0910 and says that it does a great job with this HP 2.0 bearing at 17psi. The compressor sits in my DIY baffle box in a closet about 12 feet from my listening position. Can't hear it there. The first regulator/filter and 4 foot long 4" PVC surge tank are in the closet as well.
I just did the Pump test. Turned the preamp volume up way beyond normal listening levels and put my ear close to the midrange drivers. No added noise at 3.5psi, but I hear a slight hissing sound from the midrange drivers starting at 5psi and increasing slightly in volume at 7psi. The noise does not pulse, but is a smooth and faint sound of air flow. Sounds a bit like tube rush. The noise does not seem to increase as I move up from 7psi to 17psi. I can't really hear it at my listening positions at max listening volume, but I think your point is that if I can hear it, it is affecting the performance of the arm. Any suggestions on how to reduce/eliminate this (may be solved with the HP manifold)?
Agree that the air bladders are, and have always been, a PITA. I recently called VPI about the leakage issue and they sent me some modified round rubber bushings to place around the outside of the schrader valve so that it seals the metal cap to the corner pods. Seems to be working great so far.
The AT616s are so cool looking on your TNT. I saw a set on "that auction site" for 400 bills. They show some deformation on the top. For that price, I would want an audible improvement over the air bladders in addition to eliminating the aggravation of maintaining level. Any opinion on that?
Thanks again, Chris.
Best,
Dave |
Hi Dave After converting the TNT to thread drive and eliminating the tri-pulley system, I made a 2 spring I-beam and moved the weight way out on the I-beam (past 6). All three of these tweaks made a significant improvement in sound quality and it was all free! You gotta love that. For me improving sound for nothing is the best "lasting" feeling in this hobby. Its a special feeling imo when you discover something on your own. I guess because I want to know why it works. It needs to be repeatable and when reversed, should bring things back to where you were. I was wondering if anyone has experience with even higher pressures with the stock 2.0 manifold? I think 12psi is probably pushing it, so thought I would ask here before going higher. When you refer to PSI are you referring to the PSI at the pump itself or at the ET2 arm ? Reason I ask - the MEDO AC0110 pumps that I have owned in the past all lose some psi along the way. They deliver 12 at the pump itself pump but about 7-8 PSI at the actual arm. From my reading of this thread, it seems that most of you have reached a pressure “threshold” where the sound quality starts to fall off. What exactly do you hear when this happens? 01-19-12: Apbiii
...My arm is a very early version, so certainly not optimized for higher pressure, and I can feel the air escaping at 19 psi but I can't hear it yet. I have not tried to determine if it introduces significant horizontal force. As I stated in my post I could hear some of the life or vibrancy go out of the music when I increased the pressure... "Some of the life or vibrancy go out of the music" imo these are very good and effective words by Archie of what happens - "life and vibrancy" I wonder if he is still around ? Someone asked me about this on my system blog. This was part of my response. "So to answer your question based on my experience. If too much air is put through and starts affecting the spindle the actual spindle will start resonating. The detail in the music will start blurring. Its kind of like when your stylus gets a little dirt on it if you are lazy to clean it. I take notice of it from familiar recordings - something is amiss or off and you clean the stylus. Likewise sonically the music sounds thinner, leaner with less information. imo - this is how you will know what pressure psi your system can handle based on your own system / room." So I think we are all saying similar things as to what we hear. Now here is something to think about. IMO outside of our own room/gear tuning, the "PSI threshold" itself for each of our systems is determined as a result of two separate things but both need each other to work. The pump delivery system itself and the ET2, 2.5 spindle starting to vibrate/resonate. Both the pump system and the ET2 and ET2.5 can be at varying stages of setup and condition with each of us. Consider someone using a 20 year old ET2 that has never been cleaned out or has leaking air around it; over a newer one, maybe a new Et 2.5 that Bruce just delivered to someone. The beauty here is that the older one is easily cleaned and air leaks tightened and brought up to spec again. The pumps are the real moving targets here as we all use different pump setups. I am willing to bet 100 Canadian dollars if you asked Bruce in the last 20 years of the ET2, ET2.5; if there was one thing he could change he would say something about having more control over the pump systems that people have used. We can help to assess how much the PUMP is contributing to the PSI threshold with the PUMP test. Have you tried the Pump Test yet Dave ? This requires the help of a friend. ***************************************************** Turn your system on and place it on mute at lowest volume. With your ET2 setup properly (level and balanced) and NO air on - lower the stylus onto a lead in groove. Again with NO Air on - unmute the system and start raising the volume. Keep going till you reach the level on your dials that represents high volume in your room. Your room has now become a listening chamber for your system and gear and more importantly - NO PUMP. Its isolated and not a factor yet. If all is well to this point, with the stylus acting like a stethoscope in that groove, go up to one of your speakers and wait there. Tell your friend to go turn your pump on while you keep your ear up close to the speaker. ***************************************************** What do you hear when your friend turns the pump on ? Have your friend turn it off and on again. If you are hearing any noise at all, the pumps air delivery is not optimized and is sending nasties to your ET2. The noise is putting a layer in the music. This is also affecting the PSI you can run with your ET2. It is my opinion that improving the air delivery should allow you to reach the best PSI threshold for your room/gear with the high pressure manifold ET2 or ET2.5 and gain benefits. I am not a scientist. I am hobbyist, I trust my ears and I base this on my personal experience. Very Important For anyone reading that is a new ET2 user do not attempt the above test until you are familiar with the ET2, it is setup properly, level and balanced. A while back I went on a mission for a few years with pumps. I ended up with the Aridyne timeter medical pump that is used for patient respiration. You flick a switch to turn on and off. It dumps moisture at the pump just like a cars AC system. These are purchased on ebay cheaply but required being picked up. They do require a separate room as they are around 60 db as far as how loud they are when you stand next to them. I have come to terms with idiosyncrasies of the VPI air bladders, but I sure would like to find some of those feet. Would be interested in hearing Ct0517's impressions of the TNT with and without the AT616s. Regarding the TNT As with noise above being the resonance vibration hobby it is - I have always found consistent results whenever we are able to remove "noise or structure feedback" from entering our system/gear. The result being more music comes through for us. We have all experienced this sensation and it generates the same kind of comments on the forums - "I did not realize the "noise" was there until it was removed" The TNT and thread - congratulations for implementing this! this was a biggie for me. A sort of analog revelation. http://cgim.audiogon.com/i/vs/i/f/1366420145.jpgIf you read my system blog thread, the thread controlled with the SDS controller, truly elevated the performance of the TNT. Air bladders like the VPI legs work but keeping them inflated and level can be a PITA and as we know out of level is disaster for an air bearing tonearm. I found the Pneumatic AT616 footers insulate and decouple really well, but where they supersede others is that they have a smooth and excellent leveling system - and once set - don't go out of level. The Verdier also has a pneumatic suspension. Welcome to the thread Dave. Very nice setup btw. I wish everyone here could post virtual systems. sorry for the long post and any errors. Cheers Chris |
Thanks Frogman. I did experiment with higher pressures (15-17 psi) over the last couple days and my ears are telling me that sonic differences between 5psi and 12psi are very subtle and I really can't discern any improvement above 12psi. Maybe that's why Herb Wolfe (Airtech Audio) chose 12 psi for his WISA upgrade way back when (before the HP manifold was available)... I was reading back through this thread tonight and found this: 01-19-12: Apbiii ...My arm is a very early version, so certainly not optimized for higher pressure, and I can feel the air escaping at 19 psi but I can't hear it yet. I have not tried to determine if it introduces significant horizontal force. As I stated in my post I could hear some of the life or vibrancy go out of the music when I increased the pressure... and this: 01-20-12: Apbiii ...Frogman the change in sound with changing pressure was fairly subtle prior to the suspension change and since the change is essentially nonexistent... Seems to confirm what I am hearing with the stock manifold. Can't wait to get the HP manifold. While reading through the thread, I took a look at Ct0517's system(s). Holy cow! That's some serious gear. I was especially stoked to see his TNT setup with the Audio Technica A616 footers: >http://cgim.audiogon.com/i/vs/i/f/1366420145.jpg
I have come to terms with idiosyncrasies of the VPI air bladders, but I sure would like to find some of those feet. Would be interested in hearing Ct0517's impressions of the TNT with and without the AT616s. Best, Dave |
I have not used the low pressure bearing with anything other than the stock pump and then the Wisa, which Bruce considers "high-pressure". I know that he feels that the arm with regular bearing performs best with lower pressure, but like you, I experienced considerably better sound with the Wisa's higher pressure with regular bearing. When I later upgraded to the HP bearing it worked well with the Wisa, but nothing like the large jump in performance that I experienced with the move to the Medo compressor (+\- 30 PSI). Welcome to the thread. |
Hello fellow ET owners! I recently resurrected my TNT/ET Two (2.0) rig and thanks to this thread and a lot of advice and encouragement from Frogman, the sound quality is now the best I have heard from my system: Dave's systemAfter converting the TNT to thread drive and eliminating the tri-pulley system, I made a 2 spring I-beam and moved the weight way out on the I-beam (past 6). All three of these tweaks made a significant improvement in sound quality and it was all free! I then started working toward improving the air supply to the arm. I was using a WISA 300 and the ET pump together out-of-phase into a makeshift surge tank (could not find the old Airtech in the attic). On Frogman’s recommendation, I build a 4ft long 4” PVC surge tank and bought a Medo AC0910 compressor. Assembled two regulator/filter units, a standard pressure one between the Medo and the surge tank and a second low pressure unit right before the arm. Also built a DIY baffle box to reduce the noise from the Medo. Made it quieter than the WISA. Pics of most of this are at the link above. One other improvement was adding a high-quality check valve under the table just before the arm. I read about this on another thread and it really makes a significant difference in sound quality, similar in magnitude to adding the bigger surge tank. Called Bruce about a HP manifold for the 2.0 (no more 2.5’s available) and he said it would take about 3 weeks to make one for me, so I am now experimenting with the new air rig and the standard 2.0 manifold. Started at 5psi at the arm. Good improvement over the old WISA/ET pump setup (~3psi at the arm). Went to 7 psi, not much difference from 5psi. Then cranked it up to 12psi. Blacker background, tighter and more tuneful bass, but maybe not quite as open in the highs as at 7psi (only slightly less open, if at all). Perhaps it is just smoother, eliminating some arm resonance occurring at the lower pressure that I mistook for open-ness… I was wondering if anyone has experience with even higher pressures with the stock 2.0 manifold? I think 12psi is probably pushing it, so thought I would ask here before going higher. From my reading of this thread, it seems that most of you have reached a pressure “threshold” where the sound quality starts to fall off. What exactly do you hear when this happens? I really like this thread and all suggestions will be appreciated. Thanks again to Frogman for his excellent tutelage and encouragement. Dave |
HF Dover.
Compressor is a piston type, which one would think would produce a pulsating air flow. Certainly the piston type loaner they gave me failed the Chris T noise test. The difference this time around is as follows. I'm using two regulators in series. I have a small restrictor between them, ( a trick we sometimes use for low pressure pilot hydraulics). The tank is a little larger. Its set/ reset pressures are much higher 120/80 psi v/s 60/40 psi.
I said earlier that it turned back on too frequently at around every 7 mins. When it does turn on, it only runs for approx 10 seconds. Obviously a larger tank will not only increase the rest time but also increase this on time. I could lower the reset pressure, giving a longer rest time, but there would be a corresponding increase in run time so don't plan to do this since the compressor is acoustically noisy. This can't be heard in the listening room but can in other parts of the house. Also I suspect that the regulators are more stable with a high delta P, contributing to the smooth air flow. This is certainly the case with hydraulic regulators. |
Richardkrebs 11-05-13: Richardkrebs
Frogman.
"gas powered compressor with large storage tank"
This is kinda what I'm using now. It is a small shop air compressor. oil less type. What type of compressor are you using ? |
Frogman.
"gas powered compressor with large storage tank"
This is kinda what I'm using now. It is a small shop air compressor. oil less type. It pumps the tank up to 120psi and switches off. Switching on again at 80 psi. The output is fed thru two regulators in series, bringing the pressure down to 18 psi for the arm.
Doing the Chris T stylus on a stationary record test, results in zero noise change out of the speakers at full volume.
The compressor turns on too frequently at present, about every 7 mins, so I will be adding an auxiliary tank to increase the time span but this is not a priority since... I hear a slight, I think, maybe, possibly, increase in noise while the compressor is running but if it is there at all, it is minute. |
****As we all know there are two parts to optimization of the ET 2.0, 2.5.
1) Arm setup
2) Air delivery
When the thread started I ranked the importance of the two as far as sonic upgrades went
1) 40%, 2) 60% based on my private experience.****
Completely agree. In fact, I am convinced, given the dramatic effects of varying pressure, surge tanks, cleanliness of the bearing, etc., that the Holy Grail is a gas-powered compressor with large storage tank, so that the pulses of the pump's action can be eliminated completely; akin to battery-run power supplies in electronics. Alas, I have to draw the line somewhere. |
If you want to get at beyond - lets say for example 7/10 with the performance of your ET2, you need to understand how the I Beam tuning can work for you... fwiw - looking back now when this thread started, I can say I was at 6.5 - 7 with my ET2, ET 2.5 setup. This is a personal subjective number. I feel now I am around 7.5. thanks to everyone on this thread. Much to learn. As we all know there are two parts to optimization of the ET 2.0, 2.5. 1) Arm setup 2) Air delivery When the thread started I ranked the importance of the two as far as sonic upgrades went 1) 40%, 2) 60% based on my private experience. With the help of this thread I can say the percentages for me are now 1) 45%, 2) 55%. The gap is closing. As I learn more I hope to make them equal. Cheers |
Frogman - I hope you don't mind me referencing this post. But it was a sort of an - awakening - for me in truly understanding how this ET2 works. 01-09-12: Frogman
****Throwing weight at the I-beam near the spindle pivot does not increase the arms rigidity.****
Exactly.
BTW, there is a (not particularly elegant) way to experiment with lowering the I-beam compliance without use of the double spring. You can wedge (carefully, of course) a very thin piece of some very rigid material cut to fit that space, into the cavity between the spring and outer end of the counterweight cap/clamp. This will effectively allow LESS horizontal movement of the I-beam. I think you will all be very surprised at the
difference in sound.
Ain't this fun? IMO - based on my own experience If you want to get at beyond - lets say for example 7/10 with the performance of your ET2, you need to understand how the I Beam tuning can work for you in your own room/setup as it is a resonance hobby. The resonance of the Ibeam goes higher with a stiffer IBeam - this has been discussed here. Play with it - make it gel with your cartridge. fwiw - at this point even with a single leaf spring and no tuning it is still my reference tonearm. This tuning just makes the delta bigger with the others. |
Manitunc: I haven't been following this thread as closely as I should...the reason is posted below.
If you've read through from the beginning, I found THE answer to the surge tank/filter that eluded most of us 20 + years ago. For around $100.00 bucks, you can have it all without the usual "placement" issues of the past.
PM me, I'll give you the info.
"For whatever reason, I've never received updates to my inbox for anything I've posted or responded to on A'gon. This is mostly why I never respond. I've tried to address this with A'gon for years, no resolution..." |
Look forward to your impressions Manitunc.
BTW - I totally blame Frogman for any "OCD'ing" on the single, double and triple springs.
This ET2 thread/book is only 19 pages long. I think it happened around page 3 or 4.
fwiw - I like the triple spring with my XV1 but if I had to choose only one to do all cartridges I own, it would probably be the double spring for me.
Try 19 PSI with your ET 2.5 - :^)
Cheers |
I dont think the seller knew much and may have been selling for someone else. No indication he know that the two arms were even different from each other.
but, I will try your plastic piece idea. |
"imo its never OCD when you are actually changing the laws of physics"
this comment came across wrong and was not what I meant. I take it back since this particular thread does not allow one to edit. the rest of the post stands :^) |
am I now entering another world of obsessive complusive behaviour LOL - imo its never OCD when you are actually changing the laws of physics and are able to hear it in your room. Vinyl is an electro mechanical vibration resonance hobby. Try this test Manitunc and anyone else. Fetch a white plastic juice or other fluid container from your recycling bin. Using a flat side cut a small piece of plastic out - a little smaller than your leaf spring on the I beam. Now insert it into the gap where the leaf spring is, making the I Beam more rigid. Now play a few really familiar records. Do you hear any difference in your room as far as sonics go. If no change carry on with life as normal. If you do hear a change and don't care; carry on with life as normal again. If you do hear a change and are a little curious - do this proper as it costs only a couple of dollars. Have Bruce send you a couple I beams and loose springs to make into a double and triple I Beam so you have one of each to try with your cartridge or cartridges. Manitunc have a closer look at all those I Beams you now have. You may see in fact two springs glued together already. Some may have a small square damper on them while others may be just one naked spring glued in. What PSI does the ET 2.5 run at? Ask the person you bought it from what PSI Bruce set it up for. Hopefully he will know. Cheers |
I have some extra I beams,but not leaf springs. What is the advantage of multiple leaf springs or am I now entering another world of obsessive complusive behaviour.
Yeah, the tank is much bigger than my previous 4" round, 18" long chamber. What PSI does the et2.5 run at? |
If appears you've struck an ET 2.0 2.5 motherlode Manitunc. Big honkin air chamber. 6" pvc about 2.5' long An indicator to me that someone understood how important air delivery was and was careful with his stuff. thats the type of surge tank - PVC - different dimensions that I used with my Medo pump before my current one. Look inside the pipe - maybe there is a surprise :^) But its probably sealed with silicone. Would have liked to have seen the look on your face when u opened up the package. Did you get multiple I beams or a set of loose leaf springs in any of the containers? With multiple cartridges on different ET2's and a ET 2.5, I would be setting up some single, double, and triple leaf spring I Beams ready to go - to dial the cartridges into your room. What a great hobby? Congratulations |
Well, the package arrived today, very well packed. Two Magnesium wands, one aluminum, two full et2 tonearms without arm wands but with damping troughs installed. One extra base, one extra arm lift rod.
One of the arms has a 19mm tube, the other 16mm, so am I to assume that the bigger one is a et2.5, or has a high pressure manifold? Have I finally got one after 6 purchases? (i had sold one earlier this year)the fatter one looks a little newer too, less wear on the writing, but both look in very good shape.
Big honkin air chamber. 6" pvc about 2.5' long. Big pressure guage to on the air chamber, and a bunch of little parts like vtf weights and arms. I'll get them up and running, and see which I will keep, and on what. |
10-28-13: Ct0517
Now you can maybe sell Richard one of your extra Mag wands that he desires ? Economics 101 - from my university days - If one were to put a value on the time spent trawling the net for a second hand arm wand, one would find that it is indeed more economic to simply purchase a new Magnesium wand direct from Eminent Technology. According to my last correspondence with Bruce a few months ago, they were still available, albeit there is no lead filled version for those who ill advisedly continue to attempt to make a Kuzma out of an ET. |
Cool..thanks for sharing Manitunc. |
