Eminent Technology ET-2 Tonearm Owners

Philcoffino: Your observation in regards to the runout groove being more steeply pitched is right on. Every record is different. I was curious as to what kind of damping if any, you are using? Trough, magnet, or none?

Hi Philcoffino – welcome to the thread. Interesting point about the smaller circle and built up energy ? I need to give that some thought. The smaller circle is what caused the most problems for me when I tried to convert a belt drive designed TT to thread drive. Pitch stability suffered when longer thread was used.

I will say “again” any one with an ET-2 on a suspended TT needs to pay extra attention to detail. Here are 3 additional leveling tips based on taking down and remounting the ET 2.0 / 2.5 over 20 times in the last year. 4 different tables plinths / no plinths and also 4 armpods.

These 3 techniques saved me a lot time and frustration.

I went to one of those neat hardware stores and bought a level that is as close to the same length/size as the ET2 Straightline Jig.

1) Place it on the platter in the EXACT line that your ET-2 straight line alignment jig would go – levelling this way ENSURES your platter is level in the path the arm will take.

2) The tonearm air bearing spindle is not IMO in the same exact level plane as the tonearm armpost it attaches to. It a physical connection with bolts – DON’T TRUST IT. Some of these arms are old now. Many people level the arm post. IMO - this is a mistake.

Use Blue Tac (Fun Tac) a little heavier than the cartridge on the counterweights to raise the Arm Tube and Cartridge and have the Bearing Spindle float with gravity. Adjust armpost vertical screws until it does not move either way.

3) While arm is floating (in 2) move wires around with pencil or your finger – Fix/dress the wires so they don’t affect the arm. Do this with the arm raised at the START and END of the record.

If the above three points are done the stylus "run-in" and "run-out" should be the same.

Thoughts?

Rebounding arm fix!

I thank the forum contributors for their suggestions.
Careful leveling has mitigated but not solved the problem. Rebound is now observed only with some records, perhaps those with runout grooves more steeply pitched.

I assume that energy is stored in the I beam spring upon inward acceleration of the arm as it encounters the more steeply pitched runout groove, then suddenly decelerates when the groove becomes circular nearest the record center, and the Ibeam with associated mass gives up its energy, pitching the arm back toward the periphery.

Bruce Thigpen offered to send me an I beam with a less compliant spring, which may solve the residual problem.

Arm setup was impaired by my inability to find my stylus pressure gauge. It is useful to know that a US dime weighs ~2.2 grams. That made it possible to jury rig a balance so that my Benz Micro Ref could be set to that pressure.

Again, issues of ultimate technical performance aside (tracking), in my system with certain cartridges one spring is obviously preferable to the others, otherwise the sound can be either too lean (lower compliance spring), or too full, even bloated and diffuse (higher compliance spring). Having said that, I seldom use the single spring anymore since the improved detail retrieval and refinement that I generally hear with the double and triple springs are difficult to give up; and when the system starts to move in the direction of too lean a sound as a result of the lower compliance, I find that I can make adjustments elsewhere (VTA, slightly higher VTF, a different tube, etc.) and retain the benefits.

Frogman – What a profound post. Your experience with this ET2 tonearm, different cartridges and different I Beams just oozing out. Well maybe oozing is not the right word.

As a guideline then and remembering all our systems/rooms are different so we need to experiment and the reason we cannot call it a "silver bullet".

Summarizing this makes it clearer for me.

2 or more leaf springs - heads more toward a leaner sound due to lower compliance – more detail and refinement.

One leaf spring – best tracking - but sound can become too full, even bloated and diffuse due to the higher compliance of just one spring.

What I am hearing going from the single to double spring supports this.

Cheers

Frogman, I couldn't agree more. I just assumed that his arm was perfectly parallel with his platter's surface!

Philcoffino,
If it's not, make that adjustment first, then level your suspension with the oracle gauge to make sure that your aluminum plinth is parallel to the acrylic plinth. After that's perfect, use the arm as a level and level it by adjusting the spikes under your Oracle.

Philcoffino, a couple of things to check.

- Make sure the ARM is level, not just the platter. I will bet you an I-beam that your arm (spindle/housing) is not level, and is slightly higher in the rear. Even if a bubble level tells you that it is, try raising it slightly at the front.

- Check the dressing of the tonearm wires to make sure they are not pulling on the arm when it reaches the end of the record.

- If you are using a clamp on your tt, check to see that it's diameter is not so wide that cartridge body actually hits it at the end of the record. Had that happen with a certain carbon fiber clamp.

Ct, glad it worked out; I had a strong suspicion that you would like the result. Maybe not a silver bullet, but a significant way of optimizing cartridge performance and system tuning. Again, issues of ultimate technical performance aside (tracking), in my system with certain cartridges one spring is obviously preferable to the others, otherwise the sound can be either too lean (lower compliance spring), or too full, even bloated and diffuse (higher compliance spring). Having said that, I seldom use the single spring anymore since the improved detail retrieval and refinement that I generally hear with the double and triple springs are difficult to give up; and when the system starts to move in the direction of too lean a sound as a result of the lower compliance, I find that I can make adjustments elsewhere (VTA, slightly higher VTF, a different tube, etc.) and retain the benefits.

Regards.

Philcoffino,

Is it a Delphi? I have an ET-2 on my Delphi, but don't experience that problem. You might want to check to make sure that your platter is perfectly level. If it's not, when the cartridge gets near the end of an LP, the platter will become even slightly more un-level and cause even more acceleration of the arm as it nears the end of the LP.

Also make sure to see if you have the maximum amount of space between the joint and the manifold housing when the cartridge it at the very end of the runout groove. I have heard (no idea how true it is) that if they get too close, the air coming out of the manifold can push against the joint and cause the arm to "bounce" back across the LP. Maybe its just the joint coming in contact with the manifold and bouncing back, I don't know. Either way, you never want the joint to come in contact with the manifold. You want some buffer distance there.

Before your arm rebounds, does the joint contact the manifold? Have you ever watched it?

My ET2 rebounds wildly from runout groove. Fix?

Oracle with ET2 have been in storage for a few years. Before setting up again, I would like some help. A recurrent problem has been the arm moves toward the spindle in the runout groove, then rebounds, skittering a ways toward the record periphery. Repeat endlessly, until manual intervention. I assume that energy is stored in the I beam spring.
Easy fix?

DOUBLE LEAF SPRING I-BEAM -
Frogman thank u so much for turning me on to this.
For the small amount of $ we are talking about here I can’t stop myself from telling you guys that you should have Bruce send you:

Two I beams with the factory single leaf spring on them. They are around $15 each.

Plus three leaf springs on the side(loose).

From this you can make one double and one triple leaf spring I Beam to try out.

You probably have a single spring version already.

Have a look at what kind of condition your existing I beam /Spring is in. You may just want to replace it as well. If you have a single spring you should see damping material on the one side that was put on at the factory. This is a folded aluminum shim with inert material similar to silly putty according to Bruce.

I have just assembled a straight double leaf spring super glued together, started listening and really like what I am hearing. Bruce said no damping material is needed with the double spring and he has not tried the triple spring.

Frogman - 3 I beams in the waiting ? Single, double, triple spring versions based on the type of cartridge you want to put on ? Is this a silver bullet or one of them with this tonearm ?

Using the minimal amount of weights as far out to the end of the IBeam as possible.

Magnet in place for damping (thank u Dover)

Cheers

APbiii - here’s some interesting data on resonances from Reed.

I am sure Bruce probably has files and files of tests as well.

>Resonance Testing

Some more of their research.

Magnetic Damping - and Antiskating
I find it very interesting that pivot arm manufacturers are openly discussing the "possibility" of mechanical noises caused by regular antiskate in pivot arms.

In Reed's owns words.

"This model features magnetic antiskating technology which eliminates the possible noises brought up by the traditional mechanical antiskating."


Magnetic Antiskating & Damping

Since no one has spoke up about the ET2 magnet yet - I will say I have left it on. I guess we need to experiment with how big it can be and not effect things. My magnet is placed on the pedestal where the air bearing spindle exits. My wires now exit the arm tube and go straight down away from the Spindle. I would post a pic but I am not able to yet.
Cheers

FROGMAN... you didn't, I will be glad to clarify my statements when needed. I get on my high horse some and I thank you for pulling me back down a notch. I get too passionate about audio as everyone can see.

I have not thought much about the actual mechanics and physics of turntables and arms but some of what I read does not make much sense to me. Perhaps someone can help me understand better.

Folks talk about "draining" energy to the earth or some other place of stability as if it somehow removes the effect. This does not make sense to me. If a tone arm resonates at some frequency it seems to me that it must be moving. That movement will eventually be damped by some mass, i.e. the movement will become undetectable. The resonance will if no longer being excited die out as the energy is dissipated as heat energy raising the temperature of the resonating part.

The damage from an audible perspective would seem to me to come from the movement. For the cartridge to reproduce what is in the groove it needs to be absolutely fixed relative to the groove. If it moves relative to the groove then that movement becomes part of the electrical signal as there is no way for the cartridge motor to know if the cartridge is moving or the cantilever is moving.

What I think Bruce is saying with his measurement technique is that if you can sense movement in the headshell of a tone arm, which is what you are doing by placing another stylus / arm on the headshell as it plays a record, that movement has to be counterproductive to the faith-full reproduction of the information in the groove.

An interesting set of articles on the ET2 with a little discussion of resonance in tone arms.

http://www.stereophile.com/content/eminent-technology-two-tonearm

From the arm tube to the plinth and the energy resonances measured were very close, ie transmission rate was very high.

Dover,

Just to clarify-

The conclusions were that the unwanted energy transmitted went straight through the air bearing and out the other end relatively unimpeded.

Do you mean that the energy went from the spindle, through the air gap, into the manifold, and into the plinth?

Apbiii - Martin Colloms did some testing of energy transmission in the ET2 years ago. He measured the resonances in the arm tube and then in the arm after the air bearing. The conclusions were that the unwanted energy transmitted went straight through the air bearing and out the other end relatively unimpeded.
This is the old chestnut - do you kill unwanted energy by overdampening, or by having a drain path to ground ( the plinth ).
The main issue with overdampening is that soft materials eg rubber, will store energy and then release it "out of time" with the music, thus smearing the sound.
People will have their own preferences, do you want to hear everything, quick, coherent, lively if a little coloured, or do you like a nice smooth inoffensive sound if lacking a little speed, detail and coherence.

Its a fairly long description in the manual but basically involves putting the second arm / cartridge on top of the first while playing a track and "listening" to it to hear resonances in the first arm.

It also includes a discussion of how materials change their physical properties at resonance and become much less rigid or stiff.

ET2 MAGNET MOD - Who has tried Dover’s Magnet mod? I found a magnet I tried it. I’d like to hear someone else’s impressions first.

Hi Frogman –The drop of superglue on the Empire shaft worked like magic. The cartridge has been used alot. The last couple weeks I had noticed on really eccentric records the odd skip with the Empire. I attributed some of it to learning curve with the string drive TT. But I had a better look - the actual shaft had some play. Its always been flawless in tracking. I put one drop of superglue and the shaft where it butts up against the body. Let it set and no problems now with those records. I paid $350 for the whole thing and the stylus’ are $250 I think? so I considered it disposable as I have a second empire ?

Does anyone know if its possible separate superglue from two metal surfaces? Just curious.

Cheers

Slaw, apologies. In did not mean to come across as heavy handed. My comment was simply a statement of what I heard IN MY SYSTEM; not a suggestion that you should do the same.

Regards.

Apbii, please describe that technique. Thanks.

Slaw, apologies. In did not mean to come across as heavy handed. My comment was simply a statement of what I heard IN MY SYSTEM; not a suggestion that you should do the same.

Regards.

I have a very early ET2, so early in fact it came with an ET1 manual. Why would I mention this? Because there is a very interesting technique Bruce describes using a second tone arm and cartridge to measure arm resonance. Have any of you folks heard of this, especially those who have removed the damping materials?

Ketchup, I used the ET2 before the magnesium arm wand came out. The arm was smooth and gumetal grey under the shrinkwrap. !st I removed the heatshrink, more agile sound, then I removed the foam inside the arm tube - lighter sound but much more transparent.
For the cartridge mount I carefully prised open the end of the arm, enough to get long nosed pliers onto the soft insert and pulled it out. Then I got a thin piece of carbin fibre, cut to size, then inserted it into arm with araldite and clamped the headshell until dry.
I never compared this to the magnesium arm.
Cheers

Dover,

When you mentioned removing the heat shrink from the arm tube, which arm tube were you talking about? My aluminum tube does not have any on it, but I also have what I think is the heavy magnesium tube (it's definitely not the aluminum or carbon fiber tube, and I'm not sure if they ever made a lightweight magnesium tube). When I got it, it had heat shrink on it, but I did not know if it was factory installed or not. It was a little damaged, so I took it completely off.

What benefit did you see by removing the heat shrink? What did the metal beneath the heat shrink look like? Mine is a dull, gray color with a pretty rough surface finish, close to what 100 or 80 grit sandpaper would give.

Here's a photo and a diagram of the magnesium arm wand.

http://www.eminent-tech.com/25%20magnesium%20arm%20wand.html

http://www.eminent-tech.com/magarmtube.html

Also, how did you remove the teflon "filler" in the headshell? I assume your talking about the white material inside the arm tube where it's squished together where the cartridge mounts. What did you do, buy a sheet of carbon fiber and cut and file it until it fit in the slot? What benefit did you see from doing this?

Thanks a lot.

Frogman: You're right, I should say "In my system".

Frogman I do remember having an issue with air loss from the manifold due to a cap screw leaking. I don't remember which one it was, I resolved it by using Teflon plumbers tape on the cap screw.

Conversations with Bruce T implied that some have had problems with stripping the threads in the manifold where the adjustment block attaches.

I also think that if these screws are too loose it allows the arm to flex quite a bit which would seem to be very counterproductive.

Slaw, while I agree overall with your comments re type of suspension in the VPI line, I would qualify them with these observations IN MY SYSTEM:

The "overly warm" description is definitely system dependent. What might be overly warm in your system might be perfect in another. This also highlights semantics issues. I experimented with all types of suspensions in my sequence of VPI's (HW19mk2, 3 &4, TNT with spring and currently rubber ball suspension. I found spring suspensions (particularly with the HW19 series) to produce a more diffuse sound, not necessarily warmer. In fact, I found the sound to be less even linearly, with some highlighting of the lower highs, producing overall a sense of a brighter, not warmer, sound. This also gave the sound a livelier character; although I believe that was the result of the tonal highlighting, and less so a result of any issue of dynamics. Upturned metal cones (least compliant) in the HW19 produced a very tight, brighter and detailed sound, but too lean in my system. Sorbothane pucks with upturned short tiptoes was best. With my TNT, which began as a TNT6 plinth with original spring corner towers, the sound was again livelier but edgier and diffuse/bloated compared to the current rubber suspension.

Gotta love these mods that don't cost anything to try. WTH - honey what happened to all the magnets that used to be on the kitchen cupboards ?

Thx Dover - sounds like the our single, double metal strip IBeams are another way to accomplish this ?

Frogman - I am going to super glue the shaft of the older empire I have and connect to the body. I agree it could be alot more rigid. Will let u know how it works out.

Slaw - I should have got it in an email from Bruce.

Ct: As far as the high pressure manifols beiing "custom built", not, at least in my case. I had my (.5) upgrade done at least 15 years ago and Bruce did't ask me what pump/pressure I was using. I'm currently running 18psi,
Ketcup: I can run over 20 psi right now and not affect anything but the hose/connectors. IE: No issues regharding over 20psi into the ET 2.5 manifold.
Apbii: Any "soft" form of (suspension) in the VPI line of TT will result in a softening of transients and ,you guessed it, MUSIC.

OK guys, This is obvious, any rubber, compliant, suspension, WILL result in a overly warm, muddy, less "What we are all looking for" SOUND!!!!!

Hi Ct0517, I'm very rusty since its about 15 years since I used the ET2, but from memory I had an I beam with a thin metal strip at the bearing tube end. I packed soft strip ( might have used thin lead or teflon ) either side of the thin metal bit that goes into the bracket on the end of the bearing tube and then played around with the tightness of the clamp - I was able to vary the lossiness of the I beam from rigid to virtually floating. Then I settled the point that gave the most natural bass soundwise with air around it.
Re the magnetic dampening, I used a small cupboard door magnet and simply placed it on the turntable plinth with a packer to get the magnet as close to the bearing tube ( the moving one ) without touching it. This magnetic dampening is used by Dynavector on their tonearms where a curved horizontal metal near the counterweight moves through 2 magnets above and below it as the tonearm transverses the record.

Hi Dover – Can you tell us more about this tuning of the ET2 leaf spring by torque ? on the compliance thread. Looks interesting.

Frogman have u or others tried this ?

Linear Tracking Arms Compliance Thread

01-16-12: Dover
Atmasphere, when I used an ET2 many years ago these issues were ameliorated by
Using as light a counterweight as possible mounted on a horizontal leaf spring. By tuning the leaf spring through loosening the clamp you could reduce the initial horizontal effective mass when eccentric records generate side force.
The other trick I used was to place a small magnet under the horizontal bearing tube ( not touching it ). This effectively provides horizontal dampening far superior to using a fluid trough. It was so effective that the volume of the preamplifier had to be reduced - very surprising.

Dover (Threads | Answers | This Thread)

Dover how did u attach the magnet to the ET2? I'd email u for a pic but can't yet.

Cheers

Ct, please keep us posted re the use of the double spring. BTW, I have been tempted, but resisted so far, to super glue the stylus assembly/carrier to the cartridge body. I did it to my ATML170OCC for a nice improvement in refinement. Those removable stylus carriers even though they appear to fit tightly in the body of the cart will benefit from the extra rigidity.

Apbii, my comment about clogged capillaries was a general comment. It doesn't sound like yours are clogged. But I realized that I misspoke (miswrote?) in my comment about the over tightening of the bolts. I was
referring to the two bolts (four total) on either side of the VTA block. I never asked Bruce about this in the handful of conversations I have had with him over the years, but I suspect that in the case of my arm it was a machining error that caused those holes to be tapped so long to pierce the manifold housing. Perhaps not, and all arms are that way so careful with over tightening.

David, re suitable tables: I first mounted my ET on a VPI HW19 Mk 2, upgraded to a MK 3, then a Mk 4, and currently my TNT Mk 6 (actually,
it's a bit of a hybrid. Mk 6 with a Mk 5 platter). That series of tables make terrific platforms for the ET. There is ample space for the arm, and the spring suspension can be replaced with less compliant sorbothane or cones which is ideal for the ET. When the ET first came on the market it was the general consensus that a non-sprung table was best; although I always found it interesting that the ET website and manual shows it mounted on a SOTA which is sprung. Another popular combination was the ET on the Oracle; and man, that combination LOOKS cool. Personally, I would look for a HW19 MK2,3, or 4(best) if you want a
moderately priced table. Not sure what you consider moderately priced, but an older TNT is even better. I am currently lusting after a Technics SP10 MK2, which I suspect would be a fantastic combo with the ET on the right plinth.

Hi Frogman – With all the cartridges you must have heard over the years on the ET2, thanx for confirming what am hearing with this Empire 4000 DIII cartridge . Thanks also for retrieving all those comments from that MM thread. Fantastic info.

For the the $350 -400 that I paid for each of these Empires they deliver alot of performance. I bought one on whim from following the MM thread. Having then heard it I figured what the hell this could work for what I had planned so I bought another. So two ET tonearms and 2 Empires helping me with my playing around with these TT's.

3 leaf springs and IBeam are still in mail and have not arrived yet. Will be keeping the Empire on and trying with a double spring as you suggest as soon as they come in. Looking forward to that. Then will be switching back to my favourite MC - in this case it happens to be a Benz Micro MC 3 which is SS Ruby Retip.
I have an old XV1 being rebuilt by Axel in Germany per the MM thread. Am anxious to get it back but very patient as he is hopefully bringing it back from the dead.

Currently listening with lead weights positioned as far back as possible on the I- Beam.

Cheers Chris

C1 if you are really interested in visitors let me know, I would love to hear your Dalis.

Frogman the change in sound with changing pressure was fairly subtle prior to the suspension change and since the change is essentially nonexistent.

I don't think the manifold is clogged as the pressure is in the correct range with the original pump. I have had the manifold out and cleaned it but it was some time ago.

If I get bored perhaps I should do it again just to be sure.

Chris, I love the Empire. I think it is a terrific cartridge, and have used it long enough to form an opinion. From a technical point of view, I had no performance issues with it in the ET. Tracking was very good, even if not quite as solid as cartridges like my Monster AG2000 (ZYX), and VDH Grasshopper. IN MY SETUP the double spring I beam is a must in order to firm up what can be a bit of excessive fullness. These are some comments I posted a while back in Raul's MM/MC thread. I hope you find them useful:

*****I just received, and installed a NOS Empire 4000D III Gold. I am
VERY impressed. I have been somewhat lukewarm about the whole issue of the claimed superiority of MM's relative to MC's; and still, overall, in the MC camp. I own ATML170, Azden PVL 50, Andante, and while I recognize what they do well (very well, particularly in the case of the AT and Azden), I have still been unconvinced. The Empire could change all that.

I am interested in hearing from you guys about your findings re break-in, VTA, VTF, viscous damping, etc., in order to optimize it's performance.
Thanks.****

****Thanks guys. I have the Empire in a Eminent Technology 2 air bearing tonearm with the high-pressure manifold and pump; on a VPI TNT6 with "the works". So far, initial impressions are: Terrific clarity, with good inner detail. Tonally, a good middle ground between the white/bleached sound of the Andante, and the more romantic/golden flavor flavor of the Azden.
Open soundstage with good placement. Sound is definitely weighted towards the midrange, and so far seems a little bloated. That is why I ask
about break-in, and damping; a hunch tells me that things will even-out (tighten) a bit after a few more hours. But, in general, so far I like it better than the vaunted ATML170, which in my set-up seems a little slow/slightly boring in comparison. I am going to try fluid damping over the next couple of days and report back.****

****Dear Raul, thank you for your thoughts. I find the Empire to be anything but boring. It is, in fact, very alive sounding. That quality (or it's absence) is the most important performance consideration for me. If the component does not allow the music to move as it should, it doesn't
matter how great it's frequency extension, soundstaging, or tonal refinement is. That is what I meant by "boring" in reference to the ATML170. It is clearly an excellent cartridge in most respects, but in comparison to the Empire (and my MC's), it sounds just a little bit slow; rhythmically laid back. The Empire, in the exact same system sounds very alive, and lets the music move as it should. The AT has superior detailing of the soundstage, with more stable placement, but also sounds a little
closed-in in the highs; not enough natural color. I know "color" is considered a great sin by many audiophiles, but music has a tremendous amount of color, and some components seem to "bleach" the color out of
instruments' timbre. Everything then sounds very much the same, with a gray(ish) color; mistakenly referred to as "neutral". I am sure you are correct, and that 100K loading would improve that.****

****That is still my main issue with MM's in general. Until I heard the Empire 4000D III, every MM that I had tried, including the ATML170OCC, has sounded too relaxed to me. Not bad by any means, but compared to a good MC, without that essential quality of excitement in the rhythm of the music; like a coiled spring ready to unwind at any moment. I am still getting to know the Empire, and I am still not ready to say that in the dynamics (micro/macro) department it is the equal of my VDH MC's.****

Hi Chris,

The pressure gauge indicates the Wolfe-modified WISA pump operates satisfactorily; the system experiences a drastic pressure drop at the surge tank...there appears to be occlusion, there.

I'd like to keep the arm; however, at some point, I'll look for a non-suspended table :-)

It's in the forties, now...brrr.

-Sam

Hi Sam - Welcome to the thread. The one where tonearm owners need life support for their straight lines; all in the name of no tracking distortion and natural sounds. Heh, heh

Two Bruce’s in HI FI eh ?

Sam - Don’t you have a leaky original pump ?

There is probably an ET2 owner near you - otherwise it is 0 degrees Celsius here – about 32F – what if I get a work assignment there for a week ?

I’m sure Slaw can provide many tips for that VPI HW19 MKIV.

APBiii good information - I will respond with my 2 cents worth. I have been doing some experimenting.

Frogman - can I ask what you think of this Empire 4000 DIII on the ET2 ? Don’t you also have one? Did u use it long enough to form an opinion? How does it compare to the many cartridges you have had on this tonearm?

Cheers

When are you guys coming over? :-)

Siriusly -hehe- when I had Bruce, no -- not that Bruce -- from Stereo Unlimited in San Diego set-up my deck, ET2 with VPI HW-19 Mk.IV, it sounded wonderful...

I'll get back to that sound, someday!

Thanks all for the great exchange of information :-)

Vbr,
Sam

Apbiii, I have never experienced what could be described as a decrease in performance by increasing the pressure; although I am sure there comes a point, as I think you found out with your regular manifold, at which the arm does not work optimally due to the higher pressure. The reason I like 17 psi and no higher is that because of the way my system is tuned, 17 psi is the most complementary. Higher pressure produces a sound that is too lean and overly controlled. I have no doubt that in a different system, with my cartridge, the arm would sound better at the higher pressure.

I am intrigued by your observation that with the rubber ball suspension
(lower compliance) you don't hear as much of the dulling of the sound with psi above 15. If your non-high pressure manifold is given higher psi, it's possible that the resulting instability due to the "turbulence" in the larger gap between the manifold wall and the bearing tube is made worse by the higher compliance of the tt's suspension.

A couple of other comments/ observations that come to mind about the arm:

-The capillaries do get clogged over time. Years ago I experienced a gradual dulling of the sound with eventual poor tracking. The problem was clogged capillaries. It is tedious but not difficult to clean them. DO NOT do what I have seen suggested in a couple of forums. Do not try to clean them by forcing alcohol through "the system". I tried it and made matters worse. The manifold must be removed and all the capillaries unscrewed off the manifold and cleaned individually with alcohol. The difference in sound from doing this was significant.

-Do not over tighten the two bolts that secure the manifold housing to the pillar. In some arms (mine) the holes for the bolts are tapped too long and will actually go into the inside of the manifold housing and dislodge the piece of tape that is in place to seal and make airtight the housing. The result is escaping air and decrease in pressure.

Hi David - please tell us what moderately priced TT means -budget range ? Does it have to be brand new ?

As I look at my naked TNT II without tonerarm I can see the one bolt that secures the ET2. The bolt is located about 2 5/8 inches from the nearest part of the platter and one inch above the spindle. Draw a horizontal line one inch above the spindle. a vertical line 2 5/8 inches beside platter. Where they join is the spot approximately just to give you an idea. It can be mounted anywhere "around" the platter as you only need a straight line to make it work.

It is a universal mount design only the one threaded bolt needs to be drilled unless you plan on running wires and the air tube through a plinth as well.

You can get info by going to the Eminent Technology website.

Go to Support, Manuals ET2 Manual Part 2 - See Pages 62-63

or

The manual can also be downloaded from Vinyl Engine
ET-2 Manual

Let us know if any questions.

Cheers Chris

Since no one has responded I will post my thoughts and see if anyone comments.

I think of it this way:

As the pressure is increased the volume of air used increases and this is dependent on the clearance between the manifold and spindle. At some point that escaping air will become obvious in two ways, one being the noise created and the other will be horizontal force on the arm at the end of travel.

The increase in pressure will also make the tube / manifold interface stiffer and I think this is what causes the increased performance. It seems to me the the stiffer the better as long as other factors such as oscillations, vibration etc. from the escaping air don't rise to a
level that they cause problems.

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 but since I have tightened up the suspension I no longer notice this change.

It would be interesting to ask Bruce about this. I suspect that as the pressure increases he reduces the clearance between the manifold and tube. There must be a point of diminishing returns and I wonder where he thinks it is.

As I think back on what I did I also made some adjustments to tighten things up on the arm / mounting board around the same time I changed the suspension so that may also be a factor.

I should plumb the pressure regulator so I can sit at the listening position and adjust the pressure so it is easier to evaluate changes.

If one were to purchase a new ET 2.5 today, can anyone recommend a new, moderately priced turntable that could be fit with an arm board that is compatible ?

Can you visually inspect an ET 2 manifold to determine what PSI its set up for ?

Chris,

The manifolds look the same, there were no exterior markings. You would need a pressure and flow gauge to determine the manifold type. Thanks

brucet

On 1/17/2012 9:49 PM, wrote:

Hi Bruce
A question from an owner that bought an ET2 used.
other than hooking it up to a pump to see what it can handle -
Is it possible to visually inspect a manifold to determine what pressure it's set up for ?
Can the differences be seen - Are there specs for the different PSI's ?

thank u - Chris

Full Disclaimer – I am not a dealer, distributor, or manufacturer of this ET2 tonearm. I am just a user and a fan. I started this thread looking for an exchange of information between ET2 owners new, experienced and soon to be, with the objective that we can all improve our ET2 setups through these discussions.

Can anyone describe the symptoms / downside of over pressure?

Initially (recent history as I have had this arm since '85) it seemed that the music dulled a bit above 16 psi.

After replacing the spring suspension in my TNT mk 1? with delrin cups and racquet balls I don't think I can hear any difference between 15 - 19 psi.

That last sentence should read, "Maybe he could let us know the specs that he built them to for different pressures."

Ct0517, good info. What I would like to know is how to inspect a manifold to determine what pressure it's set up for. I would guess that things like the spindle/manifold clearances and capillary size would need to be measured. Did Bruce mention how to determine this? Maybe he could let us know the specs that he built the to for different pressures.

How much weight can the ET-2, ET-2.5 designs carry on the I Beam ?

I hope that this will help to clear up ALOT of questions with some of you. It did for me.

The high pressure manifolds are not all the same. The ET 2 and ET 2.5 high pressure manifolds were built based on customer specifications for the pumps they were planning on using. So there are different versions. The higher pressure versions of these will handle more PSI and will also handle more weight. How much weight ?

On January 3rd - I posted this information from Bruce regarding adding more weight.

Chris
Adding weight in this direction causes an asymmetric load on the air bearing so there will be a point where the bearing may bottom at the end of play position.
The other thing to consider is the suspension system of the turntable, you are adding moving mass, this weight moving laterally may cause the suspension to deflect and change the state of level of the tonearm. Increasing the horizontal inertia can cause increased rumble.
As long as you understand these potential problems it does not hurt to experiment and have fun. Thanks

brucet

In Support of this.

Here is an email trail from “today” to help as well. Understand that the ET-2 Design and the existing ET2.0 manual is based on the original design running at 3 – 3.5 psi from years ago

On 1/17/2012 7:35 AM, wrote:
Hi Bruce

The ET-2 is provided with counterweights for 15 grams.

The use of less weight with lighter cartridges as the manual discusses is preferred - and the goal is to keep the weight at the end of the IBeam (higher number).

The manual says we can add more weights up to 20 grams.

Is the 20 gram a threshold number where after that, the weight affects the arm in a negative way?

What did your studies show will happen to the arm with more weight than 20 gms?

Thank u.

Chris

--------------------------------

Chris,

Use the minimum amount of weight far back on the beam meaning beyond scale number 4. The only limitation is air bearing binding at the extremes of travel due to the asymmetric load. If your air bearing will carry the load you can put any amount of weight on it. I hope this helps.

brucet

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Thx Bruce - in your opinion does a higher air pressure 20 psi coming out of the manifold allow for more weight to be placed on the I Beam than say 6 psi.

Does the higher 20 PSI support the air bearing better for more weight than say 6 PSI or does it have nothing to do with it.

Chris

-----------------------------------

Chris,

Yes, higher pressure should allow you to carry more weight. – brucet

REVELATION PART OF IT

I then called Bruce.

I found out that all these ET 2.5’s manifolds are designed based on the pumps that were to be used with them by the customers ordering them. They will not all do 20 psi at the arm. If you bought a new ET 2.5 the manifold has been built for the pump you are using or told Bruce you were going to use.

If you bought it used what was the previous pressure the owner was using? If you don’t know there is an easy answer – bump up the pressure and listen to what happens. When does it hit the brick wall? It sounds like for some here it is 15 psi – 17 psi. For others 20 psi is not an issue and maybe beyond.

My ET 2.5 manifold was designed for 20 + psi. How do I know? I had Bruce do the update from a ET 2.0 last year and told him I was running 20 psi on it and above. It still works at 10 and 15 psi but I can also go to 20 psi + with no issues and I now intend to try 25 -30 PSI with a different hose and see what happens.

I hope this clears up questions.

BTW – If it is not obvious from the Jan 3rd post Bruce does not know how much weight a high pressure spindle designed for 20 psi can carry. He did tell me definitely more than 20 gms. Too many factors involved including the turntable – like if is suspended, and other considerations ….

This is why he says experiment and have fun.

Cheers

I hate these long posts - sorry for any errors.

Hi Frogman,

For direct couple counterweight, I am thinking of fabricating something similar to the Walker
http://www.6moons.com/audioreviews/walker4/vtf%20and%20center%20gravity.jpg

I think it is probably important to keep the total weight of this counterweight assemble close to that of the original design.

Cheers!