Eminent Technology ET-2 Tonearm Owners

Not Utter Nonsense Dover, tell me about a resonant peak at 3 x Fr.

Dover says.
"....on an undamped standard ET with decoupled counterweight there is a resonant peak at 3 times the fundamental resonant frequency, and that this is reduced with fluid damping on a standard ET with decoupled counterweight."

I say.
"At 3x Fr the rise in response is almost zero."

In response to this question..

In the technical section you talk about phase shift beginning at 2 to 3 times the resonant frequency down to Fr.
Does this mean that there is a resonant peak at 3 x Fr or is this the point where the phase and response errors have reduced to low levels?

Bruce T says...
"This is the point where, above this frequency, the phase shift becomes minimal, as you approach the resonance frequency, the phase shift increases. I hope this helps, thank you very much."

brucet

Bruce uses the phrase "becomes minimal" I used the phrase "almost zero". Bruce and I are talking about the same phenomenon. Neither of us say it is zero because the curve is asymptotic to zero. It is this characteristic which causes designers in my industry to err on the side of caution and use 6xFr. A figure I have mentioned previously.

There is No resonant peak at 3x Fr. The amplitude and phase problems reduce the further we move above Fr. Exactly as shown on the transmissibility graph I posted, which is an accurate representation of what is happening with the arm at frequencies around Fr.

Ha_ha_he_man
Further to your request.

What I hear when making the counterweight arm solid with a suitably stiff structure and when using a low compliance cartridge is this...
The image is a little more focused. Individual elements within that image are a little more vivid.

I stress as Chris has quite corrctly pointed out, my arm is optomised for low compliance cartridges.
Further I now consider an oil trough to be manditory for this rig.

05-27-13: Richardkrebs
Dover says.
"....on an undamped standard ET with decoupled counterweight there is a resonant peak at 3 times the fundamental resonant frequency, and that this is reduced with fluid damping on a standard ET with decoupled counterweight."

I say.
"At 3x Fr the rise in response is almost zero."
In response to this question..
In the technical section you talk about phase shift beginning at 2 to 3 times the resonant frequency down to Fr.
Does this mean that there is a resonant peak at 3 x Fr or is this the point where the phase and response errors have reduced to low levels?
Bruce T says...
"This is the point where, above this frequency, the phase shift becomes minimal, as you approach the resonance frequency, the phase shift increases. I hope this helps, thank you very much."

Richardkrebs, you continue to conflate apples and oranges and misrepresent statements.

The technical section you refer to is for a standard ET, with a substantial rise in response below 20hz.

FLUID DYNAMIC DAMPING FOR THE ET-II
If a tonearm/cartridge system has a substantial rise in response below 20 Hz as most do, the phase response at the low end will be shifted and phase shift will occur beginning at 2 to 3 times the resonant frequency down to Fr

One can achieve a flat response by tuning the decoupled counterweight and keeping the horizontal mass and Q low as outlined in the ET manual and demonstrated in the Stereophile testing.

Your ET is not standard. You have doubled the horizontal mass of your arm by adding lead and you have removed the counterweight decoupling mechanism.

The effect of the 2 modifications you made to your arm is to increase the amplitude of the fundamental resonance by some 6-12db as shown by Bruce Thigpens testing.

Bruce Thigpen:
If the weight is coupled the system resonant frequency would be extremely low, a resonant frequency at 3Hz with a significant rise in response (6-12dB) results

The arm Bruce used for testing was deliberately set up with a high Q and very low compliance cartridge. The standard ET when used as outlined in the manual with a decoupled counterweight has a lower Q.

A low frequency sweep was performed twice on the tonearm, once without the damping trough and once with the damping trough. The cartridge used was of very low compliance and the tonearm was set up so that a high amplitude high Q resonance existed. The results of the test show a reduction in the amplitude of the resonance of about 8 dB (horizontal).

You continue to ignore Bruces stated view that increasing horizontal mass increases distortion

Bruce Thigpen:
If the weight is coupled the system resonant frequency would be extremely low, a resonant frequency at 3Hz with a significant rise in response (6-12dB) results, which would affect tracking slightly because of the asymmetric position of the cantilever, we opt for splitting the horizontal resonance frequency into two points and lowering the "Q" which improves tracking.

More important than tracking, the intent was to reduce the modulation effects of low frequency energy (FM and AM) that increase distortion in the cartridge,

Clearly the reduction of 8db is for a standard arm. In the case of your arm to which you have added lead, doubled the horizontal effective mass and removed the decoupling mechanism, all you are achieving is some reduction in the problems and distortions you have built into your arm.

You have misrepresented Bruce’s view on eccentric records,

05-20-13: Richardkrebs
BT uses at 30cu cartridge in his manual to calculate horizontal Fr. The arm weight he uses is 30gm plus 7gm for the cartridge. We have to assume that he is ok with this combination and that he is not worried about cantilever deflection on eccentric records.

This assumption again is just plain wrong. I quote from Bruce Thigpen’s ET website:

ET2 Manual page 47 :
“if you like to play severely eccentric records, ones with run out greater than 1/8th of an inch, then we suggest you use a low mass pivoted arm.”

It would be helpful to move this thread forward if you acknowledged the issues related to adding mass and move away from using examples, maths and quotes that are irrelevant and taken out of context.

Dover - It would be helpful to move this thread forward if you acknowledged the issues related to adding mass and move away from using examples, maths and quotes that are irrelevant and taken out of context.

Actually guys – RK and Dover. I say this with utmost respect. I don’t know about the others here but I am personally totally glazed over with these discussions – back and forth. I would prefer you take it offline?

You see I trust my ears for sound not theory. I don’t need approval of somebody for enjoying my hobby. But as this is a public chat forum and there may be others here that like to dwell in theory I Ieave you as be - this is my opinion only.

Dover - I am really looking forward to your direct experiences again with the the ET2. Or did you get a 2.5 ?

What type of pump are you going to be using?

Dover - ...........Stereophile testing.

What review was that Dover – can you point it out please?

From the one that I read.

From the Stereophile review - "As for other cartridges, I would like to see very specific suggestions from the manufacturer as to the proper combination and location of weights for a given cartridge. The arm is now too adjustable for the consumer or dealer who does not measure low frequency resonance, and I still do not fully understand how the location of the counterweight package best interacts with a given type and compliance of cartridge."

Or to narrow it down.

The arm is now too adjustable for the consumer or dealer who does not measure low frequency resonance

Well - to me it would seem a reviewer that doesn’t trust his own ears or maybe he was rushed on time? Or maybe he should just go seeDorothy

Based on that statement Dover they didn’t even get close.

Like the review that John referenced. Some nice measurements and good reading, but no mention of weight location or how many; counterweight tuning.

IMO – this ET2 and ET2.5 can be tuned to the rest of your room/gear. But you need to live with it for a while to build a reference point. Then you can start tuning. Most audiophile friends I know have no patience.

This is a question for RK and Dover.

Have either of you used a double and/or triple leaf spring with a Low Compliance cartridge on an ET2 with the weights positioned at the end of the decoupled IBeam?

RK - Further I now consider an oil trough to be manditory for this rig.

After some tweaking I am getting excellent results with the damping trough. When I used it years ago I was obviously slugging the paddle through too much oil ! I am only using 1 CC per Bruce’ instructions.

Bruce is clear in the damping trough documentation that the damping trough should NOT BE USED until one becomes familiar with the operation of the ET2 and ET 2.5 without the use of one first. The added benefit I find is the visual confirmation of levelness in the trough. , as the oil in the trough is obviously affected by gravity.

Richard - I don’t like words like mandatory and absolute in this hobby. What we are creating is make believe really? This is why I like to use words like Winnie the Pooh and Goldilocks in my system page :^)

Chris and others.
I can see how our discussion has become tedious for other readers. I apologize for this and will be more considerate moving forward.

On a bit of a side path. What happens when a new better piece of gear is installed, say new speakers.
We set them up, friends come around and after they are run in, all listener's agree that it is a big improvement. We all hear better this and more of that,......for awhile. Then it becomes the new normal and we go on the quest again for "more". Has anyone else thought that this hobby of ours is an addiction?

BTW
When Goldilocks dipped her toe in the bath, she found the temperature to be just right.

I must remember my lines
Richardkrebs .... has an increase of 6-12db at fundamental resonance
I must remember my lines
Richardkrebs .... has an increase of 6-12db at fundamental resonance
I must remember my lines
Richardkrebs .... has an increase of 6-12db at fundamental resonance
I must remember my lines ....................
Dover

Richardkrebs - Has anyone else thought that this hobby of ours is an addiction?

A strange phenomena in my household. Family members seem to think that addictions can be treated; It forced me to use a different tact. I now use the word disease instead in our house. For some reason I can’t explain, it is more effective

Ha-ha-he man – please tell me my last post brought a couple ha-ha’s to you?

FWIW – the first time I saw that I almost soiled myself. I actually printed it off and put it on our fridge. I think it helped me to bring in one amp and one speaker. (grin)

Fyi –

Here is my ET2 and ET2.5 tuning information for various compliance cartridges from the last year. From a compliance high of 50 down to 10. And VTF’s of .8 gms to 2.1gms.

ET2 and ET2.5 Cartridge Setups

Richard – fwiw - I am getting excellent early results in my room with my low compliance XV1 and triple leaf spring. 2 fat and 2 skinny weights setup according to Dorothy. :^)

If you are the least bit curious I highly recommend you listen to your setup with a decoupled I-Beam – using a triple leaf spring and just the inert lead weights.
You could try this with and without your now famous lead spindle slug?

Two I Beams and 5 loose leaf springs to make up a double and triple leaf spring can be purchased from Bruce for a very nominal amount of money. Otherwise enjoy the tunes.

Cheers

Chris.
I have added a multi spring test to the long agenda of things to try.

Liked you cartoon. How true.

Many thanks

Richard - I find the word multi-spring can be misleading.

We are actually joining (glueing) single leaf springs to make one thicker one.

Think of a truck with a leaf spring in the back.
leaf spring suspension

I see this as similar physics except we are working in a horizontal fashion not a vertical one.

The suspension becomes more compliant if we remove leaf springs from that truck. More firm if we add springs. As we add springs we need to add weight to the truck otherwise it becomes bouncy on the road. The ET2 is the same. As we add a leaf spring or two we need to increase VTF if using the same cartridge. We also need to keep the inert lead weights at the end of the I Beam for resonance control – away from the air bearing.

MOST ET2 users go wrong with the lead weights - imo - because they are coming from developed habits with a pivot arm. What do you do to increase VTF with a pivot arm? You bring the weight in more toward the bearing. The ET2 is a unique tonearm unlike any other with a decoupled counterweight. The weight needs to stay at the end away from the air bearing to not impede it and for resonance control – away from the air bearing. So we just add a weight and keep it at the end.

My direct experience – adding a leaf spring (glueing two together) to the ET2 or Et2.5 means it can carry a higher load (heavier less compliance cartridge) better. The result in sound with heavy MC is amazing. Bass is further tuned to your room by turning the counterweight cap downward or upward. This will depend on your actual room and how good your bass compression is with the speakers you are using.

Thanks again to Frogman for bringing the double and triple leaf spring to the discussion here. Bruce has been shipping loose leaf springs out with his tonearms for years. His customers probably look at them and think - wth is this for - maybe a spare ?

Apologies for making this statement without reading all I've missed. (My father passed away and I had been his primary caregiver for several years, this has severely dampened my ability to give my (all) here for quite some time).
Just wanted to add... I've been using aftermarket 80W silicon fluid available at hobby stores with no sonic degredation,( paddle barely skimming the fluid)( I use an oral syringe to add/subtract fluid as needed, it's so much easier than fiddling with the paddle!), also using DuPont NLGI #2 w/ Teflon white lithium grease in my VPI bearing (ceramic ball bearing) to excellent effect.

Ct0517: an excellent description of the goings on with the leaf spring and how it works. I only wish Bruce would have mentioned the effects and the availability of the differing leaf springs years ago. A neccessity at this moment in time and should be included in future owner's manuals.

Hello.

There has been some private questions about the design of my modified ET2.

I have included here some more photos for those who may be interested.
The target design brief was to
- eliminate all unneccesary joints.
- minimise different material count
- eliminate any unneccessary components that could move
- make it as rigid as possible
- make it as inert as possible.

These took precidence over convienence of use.

http://cgim.audiogon.com/i/vs/i/f/1370870032.jpg

The main pillar and manifold are acrylic, since the decission to make the TT plinth out of acrylic was already made. This allowed me to fuse the arm pillar to the TT chassis eliminating one joint. No allowance is made for making the spindle parallel to the platter, after the fact, but I decided to machine the bottom of the pillar should this be required. Measurements showed that this was not needed.
Two cavities are milled into the pillar. In one is glued a lead billet, the other is filled with sand.

4 X M5 capscrews in machined slots pass thru to the manifold. These are loosened and the removable VTA screw is turned to raise or lower the manifold. One turn is approx 1/2 mm (20"). Tightening the cap screws creates a very strong joint. The manifold is indexed to the pillar with a lug each end to keep it level.
The pillar manifold interface is not curved. This because I did not have the machining capability at the time of build.

2 x M2 grub screws pass thru the manifold and contact the bearing sleeve pushing it slightly towards the pillar. At 120 degree increments there are 2 small pieces of shim metal inserted in the gap between sleeve and manifold. Tightening the grub screws presses the sleeve against these shims removing the compliant o'rings from the loop.

Arm lifting is done by hand and the wand rests on a piece of foam at the cartridge end, when off the record.

The goose neck is solid aluminium made from the same grade as the spindle. The oil trough paddle is attached to the goose neck.

This is a 15 year old design, if I did it today there would be a few changes, but the fundamental architecture would be the same.

As you can see my ET has had a little surgery :-)

Richardkrebs: That is quite an unique design, so unique that it becomes very different from the standard ET design we are all using. In this respect there may be little use for any comparison. Therefore, I understand Ct0517's remark above. One thing I've been thinking about for some time for my upcoming tt project is machining tolerances. Checking my pricy platforms (Symposium, BDR) and even the acrylic top on my VPI plinth @ platter with a accurate level, there are enough variations in the degree of trueness that leaves me extremely conscious of the importance of the ability to machine as true as possible. This is one reason why I like the added flexability the stock ET design offers.

Slaw.
"Variations in the degree of trueness"
Totally agree. Since I had the luxury of building the arm and TT, almost concurrently, I could deal with these topics in real time.
Getting accurate alignment when two components are brought together from different manufacturers, without the ability to adjust, would be pure luck.

Does your design allow enough adjustment for the differing heights of the various cartridges out there? How about overhang? Any adjustment for this? Of course, these two go hand in hand most of the time.

Slaw – good to hear from you again.

You are the only music lover I am personally aware of that has the capability and makes his own custom listening chair!

Thanks for sharing the pics of your setup Richard. An obvious amount of time and passion went into your setup. Interesting the side the oil trough is on.

I have thought a couple of times of removing the back end of the ET2 that holds the railing and handle to raise and lower the ET2. My Dynavector DV505 is without a lift and I hate it; but it also at the back which makes it awkward. I like having my ET2 arm lift especially into those late listening sessions. Putting the cartridge down is not the problem – its lifting it at the end – knobby fingers and a 10 year habit with the luxury of that elegant lever – I am not taking a chance on an expensive cartridge.

I believe Dover posted that he inserted some material in the handle to decouple it more.

Slaw.

Wrong thread I know, but are you in a position to tell us about your "up coming tt project" ?

Chris.
Yes lifting off at record end is an interesting exercise after a few glases of fine NZ Pinot Gris.
Which end for the trough? The one with the least amount of joins and material changes before we get to the cartridge. In my most humble opinion :-)
Was it Townsend that put the paddle on the headshell itself?

Slaw - there are enough variations in the degree of trueness that leaves me extremely conscious of the importance of the ability to machine as true as possible.

Richardkrebs - Getting accurate alignment when two components are brought together from different manufacturers, without the ability to adjust, would be pure luck.

Slaw, RK, others...

From my experience with 7 or 8 TT’s it is very difficult imo for a TT manufacturer (without naming brands) at certain cost points to reach a certain degree of trueness between the tonearm platform and the platter (all the way around it). What I have personally learned, when you come upon a serious manufactured TT design; a different standard/level of trueness is found among other good things. Just an observation.

But then no two records are true....the source media.... and records provide a medium to reveal amazing things..... as long as the stylus is placed as correctly as possible in the groove.

So how correct is correct ? What does correct mean. Some food for thought.....

************************************************************
From 25 years ago. Not much has changed.....
“The angle that the cutterhead is placed at when a record is cut results in an included angle in the final disc. This included angle must be duplicated with the reproducing stylus or distortion will result. The problem today lies in standardization of the angle by record manufacturers and corresponding standardization by cartridge manufacturers. Presently most records are cut with resulting vertical angles between 16 and 20 degrees. The average vertical angles of cartridges manufactured today is slightly higher than 22 degrees. The result of this mismatch is less than optimum performance for many cartridges.
Although the vertical energy contained in a record represents approximately 40% of the total energy on the record (60% lateral). The distortion levels we are dealing with are quite high. In some cases, the vertical performance with certain types of distortion can be improved from 2.5% to 1% or less.”
Taken from Page 51 ET2 manual
************************************************************

Hi Bruce - a question from your past testing if you have the answer.

Did you find any relation between the included angle of vinyl records and their thickness.

Example -
Is it possible to assume that that you can have two same thickness records with different included angles?

Thanks Chris


Chris,

The standard was supposed to be 20 degrees, when you talk to people who cut records, they do not check, so it turns out to be random, close to 20 degrees, but not exact. Yes, two records of the same thickness could require different VTA settings. I hope this helps.

brucet

************************************************************

This tells me if we are going to be anal about level trueness we need to be anal about VTA because the records are cut with random included angles!

Different records even if they are the same thickness, can have different included angles. This explains to me why same thickness records sound different (bass compression / HF’s ) with the same cartridge sometimes in my room. We really do need to trust our own ears with our own cartridges and not assume a certain degree of setup for cartridge X with all our records.

So ?

For me it is very good and desirable to therefore have a high degree of level trueness (tonearm platform and platter) but it is only half the battle.

I have discovered the other half of the battle is the ability of the tonearm to adjust so that the stylus can be placed at different VTA angles in the black disc – conveniently. Meaning as the records is playing as I am listening !

Vinyl is a total mechanical process and I don’t want to stop my listening routine to adjust more parameters.

So to me having with the ET2 unlike any other tonearm I have ever personally owned .........VTA on the fly that works (meaning it does not change cartridge VTF and overhang) while the records is spinning is very important.

In the past I considered removing the ET2 VTA mechanism (I thought to make it more rigid/less resonant in effect). You see for me personally I don’t change VTA for every record. I am not that anal. But there are some records that are off compared to the other mediums digital and tape and it is noticeable in my room. I would not be without VTA on the fly with my tonearm.

Slaw – I think we are thinking the same thing in your last post ....

RichardKrebs - Yes lifting off at record end is an interesting exercise

Richard

moving speakers an inch and listening to the differences is interesting.

Changing out footers and listening to the differences can be interesting.

Trying some NZ Pinot Gris sounds really interesting !

Taking out an expensive cartridge... not interesting. :(

Which end for the trough? The one with the least amount of joins and material changes before we get to the cartridge. In my most humble opinion :-)

Great idea!

Slaw
Yes the arm has considerable vta adjustment but it cannot easily be done while playing. Chris's post clearly shows the importance of correct vta.
This adjustment on the standard ET2 with the curved pillar is a brilliant design feature and one that is was unable to emulate with mine due to the machining capability I could access back then. MK2 will address this.
Other than the three wand positions, alignment adjustments are facilitated via the gooseneck like the original.

Here is a conundrum. Stylus drag is significant, being able to slow some TT platters. What effect does this force have on cartridge alignment?
Since the cantilever is angled down towards the record, any change in drag would tend to increase or decrease this angle.
Does this mean that the stylus is not only moving in the desired x and y axises but also in the z axis due to changes in drag, I.e modulation level and frequency?
It is amazing that we get anything that sounds like music off LPs. This given the myriad of compromises and the lack of industry standards

Another Pinot Gris I think.

I can only add: when I set up a cartridge, I try hard to set the appropriate VTA for said cartridge in the "neutral zone", (my term), of the arc block. The "neutral zone".... This to me is the (center range) of the arc block, where as if I adjust upward or downward, it will have the least effect on overhang, ( which I choose to reserve for differring weights of vinyl), this is in fact the center of the arc. Logic 101! Yes, I choose to make this adjustment for the differring thickness of vinyl records. What makes the ET such a great arm (for me)is for such a choice. Despite what is written in the manual, an up or down adjustment of the arc block results in another adjustment that needs to be corrected for overhang. There is no doubt about it! Yes, I'm probably anal. So what?! If we are going to the lengths we go to to extract every inth of information from vinyl, that to me is a definition of anal. Why Fremer chose years ago to suddenly forgo this, is beyond me and frankly deminished any respect I once had for him.

Slaw- from my experience if another adjustment is needed for overhang, something is off in the setup. To break down the set up we have 3 sections.

1) Sub-base plate – the one with the 3 leveling spikes and the one bolt holding the arm. Holds all the goods.

2) Mounting base and post. (includes the VTA arc block) – holds manifold, spindle, armtube, counterweight. Mounting post needs to be level and true with platter level for VTA to work properly.

3)The actual manifold housing, air bearing spindle, along with the armtube and counterweight.

If the ET2 is setup properly, the mounting base post should be level and true with your platter. The mounting base post is after all what holds the VTA gearing that raises and lowers the ET2. The platter is what the stylus overhang reference gauge rests on. The two are a marriage.

Check level on both. How true they are to each other will determine imo how true your overhang is when you raise and lower the VTA.

Richardkrebs - Here is a conundrum. Stylus drag is significant, being able to slow some TT platters.

What about the other side of the coin?
What about a TT platter system that doesn’t slow down with stylus drag, but can’t slow down fast enough after a real tough vinyl passage?

That can sound interesting? Some really like this sound. :^)

Chris and Slaw. This whole geomerty thing is interesting.

This is how I understand it...if we set up a curved pillar in Slaw's "neutral zone" for a given record thickness, the arm will land the stylus at the same point on the LP for a range of VTA's, provided we always use the same thickness record. Change the record thickness and the stylus will land at a different place.
For a straight pillar, the stylus will land at the same point for different record thickness when setting the same VTA, but will move when we use a different VTA.
This could explain Slaw's need to adjust overhang for different thickness records.
So the choice is which feature do you want?

Chris. Speed accuracy, yes a Pandoras box.
Cheers.

06-12-13: Richardkrebs
Slaw.
"Variations in the degree of trueness"
Totally agree. Since I had the luxury of building the arm and TT, almost concurrently, I could deal with these topics in real time.
Getting accurate alignment when two components are brought together from different manufacturers, without the ability to adjust, would be pure luck.

Yes I suppose almost concurrently could be considered real time for some folk.

What you have forgotten is that the ET2 has 3 adjustable feet that ensures that the arm can be leveled for any turntable.

I should also point out to readers that engineering wise it is almost impossible to machine 2 flat surfaces, without manufacturing 2 or 3 of each component and flipping, polishing and lapping in the 2 surfaces to be mated. So in most instances the 3 footed approach of the ET2, properly anchored, will be inherently more stable than 2 “flat” surfaces mated together.

06-16-13: Ct0517

Richardkrebs - Here is a conundrum. Stylus drag is significant, being able to slow some TT platters.

What about the other side of the coin?
What about a TT platter system that doesn’t slow down with stylus drag, but can’t slow down fast enough after a real tough vinyl passage?
That can sound interesting? Some really like this sound. :^)

Ct0517 – the question I ask myself is
How can someone listen to a direct drive for 30 years, before discovering that the timing is out, and finding a “fix” ?
It would seem to me that they must be less sensitive to timing errors and other artefacts from the speed instability to have put up with this for so long.

Is it possible that the insertion of a lead slug and the removal of the counterweight decoupling on the ET may help to slow down the “sound” on those passages where the composer or conductor got it wrong?

06-15-13: Slaw
I can only add: when I set up a cartridge, I try hard to set the appropriate VTA for said cartridge in the "neutral zone", (my term), of the arc block. The "neutral zone".... This to me is the (center range) of the arc block, where as if I adjust upward or downward, it will have the least effect on overhang, ( which I choose to reserve for differring weights of vinyl), this is in fact the center of the arc. Logic 101! Yes, I choose to make this adjustment for the differring thickness of vinyl records. What makes the ET such a great arm (for me)is for such a choice. Despite what is written in the manual, an up or down adjustment of the arc block results in another adjustment that needs to be corrected for overhang. There is no doubt about it!

06-16-13: Ct0517
Slaw- from my experience if another adjustment is needed for overhang, something is off in the setup.
If the ET2 is setup properly, the mounting base post should be level and true with your platter. The mounting base post is after all what holds the VTA gearing that raises and lowers the ET2. The platter is what the stylus overhang reference gauge rests on. The two are a marriage.
Check level on both. How true they are to each other will determine imo how true your overhang is when you raise and lower the VTA.

Some discussion on overhang is required here.
Back in December last year I posted a postulation that one could consider mounting the cartridge slightly forward of the tangent line. The theory is that if you are running at the tangent then there are no lateral forces on the stylus and it will “chatter”, slowly eroding the high frequency grooves over time.

If you also go back to the Stereophile review posted and read it you will also find that when tracking at the tangent then one channel leads the other by a few milliseconds. See bottom page 86….
http://s1173.photobucket.com/user/CT-993/library/?sort=2&page=1
which can be corrected by running the cartridge forward of tangent.

Slaw- the answer to your VTA adjustability and overhang may be to add a lead slug and remove the counterweight decoupling. With this mod you wont hear any difference if the VTA is out a bit. The only downside is that playback appears in 3/4 time, even when played in 5/4 time.

Alternately, you might be better setting the VTA for the thickest record, and then use shims under the record matt to adjust up the thinner records. This way you will not have the “overhang” problem.

The issue I had with changing VTA on the fly is that the bearing tube can go out of level very easily when adjusting VTA. This may have been due to the fact that I used a single point ground when tightening the bolts holding the bearing to post. Whenever you loosen or tighten the pillar bolts you need to recheck the bearing tube is dead level.

Ct0517
The best Pinot Gris in NZ are from the Central Otago region as are the best Pinot Noir. Even the cheapies from this region will usually be better than from elsewhere in NZ. The Hawkes Bay region is known for its Cabernet/Merlots's and the Marlborough region for Sauvignon Blanc's.
Unfortunately for those with a lead fetish, they must avoid wines with high lead content as it can lead to irrascibility, irritability, confusion and even delirium.
Some of the vinyards to look out for are -
Mt Difficulty - very very good, a tonic for those who are struggling with their ET.
Wooing Tree - something aromatic you could share with Dorothy
Dry Gully - for those that are shall we say "having trouble with the waterworks".
Two Paddocks - this is owned by Sam Neil the famous NZ actor, probably one for those with too many Kangaroos in the top paddock - hence the name Two Paddocks.
As you can see there is a suitable wine for all occasions. In fact after a particularly good meal and Pinot Noir the other night I had a brainwave. I'm going to eliminate the counterweight completely. By my reckoning I can use a helium balloon to hold the cartridge up. I'm just trying to work out how to adjust tracking force up and down down in increments of 0.001g. I think I can do this with a temperature controlled environment used in tandem with the helium balloon.

Dover - The issue I had with changing VTA on the fly is that the bearing tube can go out of level very easily when adjusting VTA. This may have been due to the fact that I used a single point ground when tightening the bolts holding the bearing to post. Whenever you loosen or tighten the pillar bolts you need to recheck the bearing tube is dead level.

An observation on running the wire on the outside of the armtube.

Running the wire in this manner allows one to disengage it; set the ET2 up without it, then add the wire and see how big the influence of the wires is on the leveling of the air bearing spindle.

Its significant.

Some of you may be throwing the level of your VTA post out dealing with the wire influence? The happy face loop going direct to the preamp has worked best for me.

Also to consider - what if your TT platter goes out of level with the changes in season – have you guys ever thought about that ? Its only a few bolts to disassemble and reassemble the ET2 to check the subplate levelling.

When the pillar is assembled the vertical bolts should imo just slightly be touching making firm contact – each side very much the same. Any significant adjustment to the screws for the air bearing spindle should be an indicator that something is out. If it is go back and fix the sub plate level and your turntable platter level.

There is one more option here. More of a bandaid but what the hell. It requires some thought ahead of time. Gather the records you intend to play - lets assume eight of them for example. Sort them by thickness - greatest thickness to the least. Go in one direction with the VTA for your listening session. It will be much smoother even if your pillar post is not perfectly level. Going back and forth on the VTA will make a wrongly setup post more noticeable.

Dover – thanks for the wine recommendations. Dorothy happens to be a whiskey girl. Hardcore all the way just like the ET2. No pussy footing around here.

Her personality is also just like Bruce’s for those that have had the pleasure of talking or emailing with him. All business. If Bruce wasn’t into flying I bet he could come up with a hell of a race car :^)

When any wine is being served I accept it - as it is Gods drink. Well that’s the excuse to my wife. If I have to buy it myself I am more a red wine guy. Prefer wine I can’t see through. So it is Pinot Noir over Gris for me if I had a choice. White wine tends to taste like grape juice to me for some reason and goes down same. Car keys please....

As it is summer here now I enjoy Sleeman Cream Ale while listening to bull frogs and authentic Canadian Loons that have come home.

Correction: the review I posted was not Stereophile. It was Audio magazine, 1987, reviewer Edward M Long.

Dover: "Back in December last year I posted a postulation that one could consider mounting the cartridge slightly forward of the tangent line."

I don't believe you "posted a postulation."

You reacted to information known since Edward Long published it in the measurements section of his Audio review, year 1987 (that channel synchronization wasn't achieved until an overhang of .125 in was used).

I phoned Bruce Thigpen on the issue in 1987 ie overhang, and channel synchronization.

He said "He's probably right. I was aware of this, and should have, but never pursued it further."

We assume, I suppose, on this thread, that BT can solve all problems, but he has fingers in other pies.

John47 - We assume, I suppose, on this thread, that BT can solve all problems, but he has fingers in other pies.

No not really John - check the original post for this thread.

http://forum.audiogon.com/cgi-bin/fr.pl?eanlg&1325551242&&&/Eminent-Technology-ET-2-Tonearm-Owners

Its asking for ways (as a team)to improve the tonearm.

My personal definition of a great design is one that can be tweaked and made better without changing the basic design.

With that I have tremendous respect for people that think outside of the box and don’t follow the herd. Are willing to take some chances.

In this audio hobby with my personal experiences I could name maybe 4 or 5 individuals including BT. I believe we all have this list of people from our own experiences?

Cheers

06-17-13: John47
Correction: the review I posted was not Stereophile. It was Audio magazine, 1987, reviewer Edward M Long.
Dover: "Back in December last year I posted a postulation that one could consider mounting the cartridge slightly forward of the tangent line."
I don't believe you "posted a postulation."
You reacted to information known since Edward Long published it in the measurements section of his Audio review, year 1987 (that channel synchronization wasn't achieved until an overhang of .125 in was used).

John47 - it would be helpful if you read my posts more carefully.

This is precisely what I wrote -

Back in December last year I posted a postulation that one could consider mounting the cartridge slightly forward of the tangent line. The theory is that if you are running at the tangent then there are no lateral forces on the stylus and it will “chatter”, slowly eroding the high frequency grooves over time.

The postulation has nothing to do with the Audio article on timing differences - it is about possible tracking issues at tangent due to the lack of lateral forces on the cantilever.
This is similar to olden days cars that had kingpins in the front steering - drive in a straight line and the wheels wobble, but as soon as you turn the steering wheel off centre, then the wheels stop wobbling and start tracking securely.

The following paragraph on the timing differences between channels highlighted in the Audio article is a different issue, albeit one that has the same possible remedy of running forward of the tangent.

So when you said

I don't believe you "posted a postulation."
You reacted to information known since Edward Long published it in the measurements section of his Audio review

you are wrong.

Dover: "The theory is that if you are running at the tangent then there are no lateral forces on the stylus and it will “chatter”, slowly eroding the high frequency grooves over time."

The theory - its A theory.

I'm fully aware of engineer Tony Kriletich's ideas (as above).
He suggested running with overhang in the eighties.

I recently received my magnesium armtube from Bruce.
Here is a picture that shows some big differences between the magnesium versus aluminum armtubes

What is not so obvious in the pictures is how much beefier the head shell is on the mag tube.

Cheers

Chris.

That is one serious looking wand.

Have you tried it yet? How does it perform compared to the AL version?

Thanks

Richard, its even more serious when you hold each in your hand. They were definitely designed for two different cartridges. The mag looks like it has been lifting weights and has been on steroids all its life.

I will put it on soon and provide an update. Guess I am being a little cautious :^)

I think Ketchup still owns both armtube versions but his are on two different TT’s? Maybe if he sees this he can chime in on his experiences. Or maybe one of the other thread readers can provide input?

Cheers

Dover: I agree about the 3 point leveling of the ET. Your acknowledgement of engineering differing materials to the same level of trueness... This is what I'm getting into now, I'm aquiring a granite surface plate with a remarkably true surface that I'll be using to "true" each and every section of my upcoming tt project. The "anal" part of me would prefer that my project is as level/true as possible, all the while knowing I have the flexability/adjustability of the ET to take up the slack if needed! I know that no matter what one's skills are, they are for not if the 'right' tools aren't being applied to a project. You have some interesting points regarding overhang!

Ct0517: Whoa! My testosterone runneth over. That armwand... did I miss something?
Is this a true one-piece design? I assume you've seen the 3D printed VPI arms... any thoughts?

Richardkrebs: In response to your inquiry as to my tt project.... it's at least a year from reality. there won't be much new ground broken here, I'll be using my current VPI platter/bearing, there will be prescision engineering in all phases, a (4) pod design, (motor, pulley/pinch roller arrangement, tt plinth, ET pod.)
My hope is the "anal" focus on prescision mating of parts and excecution will be a plus. The use of differing materials from wood to high tech options. I'll either fall flat on my face or end up with something very special.

Dover: The granite surface plates vs. a CNC machine = my version of "shade tree mechanics" in my world.

Ct0517: Sorry, should have replied earlier... Holy Testosterone Batman!!!

I know I'm stretching the positive here, remember A J Conti, his claim to fame is ultra high demands on the end "TRUENESS" of his product, hence the normal acrylic platter vs. his acrylic platter and how it may compare. This is the "anal" I am speaking of, I only hope I can achieve it once.

The use of differing materials from wood to high tech options. I'll either fall flat on my face or end up with something very special.

And you will have fun and learn a lot. This is what a hobby is all about. Imo – whether the learning is happening with the music itself new/old or the equipment part – when you stop wanting to learn you start to die a slow death.

Slaw – I can share some observations in regards to TT design from my experience the last four years.

What sets my Verdier apart from other tables I own and have owned is the use of materials, an understanding of their properties and documented results from measurements that were taken. I have emailed with JC Verdier many times, he has all the information and is very open with info; just as BT is with his tonearm. BTW from pictures JC Verdier is very impressed with the ET2.5 and did not know what it was when he first saw it . The Verdier is all about decoupling with levitation. The decoupling is carried over into the spindle/platter design as the spindle is brass and the platter Aluminum.

My Jean Nantais Lenco uses a Metacrylate mat that JN bonded to the stock Lenco platter to become one. You would never know it was not part of its original design if I didn’t tell you. His plinth is meant to become one “thing” 100 pounds worth with the top plate and tonearm. The top plate holding the platter from what I see must be fixed to the plinth in a way that it is “bonded” to it as well just like the Met mat and becomes part of - for the idler resonance control. I don’t like the spindle as it fatter.

My learning/hobby TT has been the SP10MKII. I am on version ?? now :^). It sounds better with the copper platter but I fear I will screw up the servo on it due to the weight. The latest version can be seen in my virtual system.

Whoa! My testosterone runneth over. That armwand... did I miss something?

Mounted today :^) Its too hot to go outside. The CF version is in the pic too.

Richard

It sounds better with the copper platter but I fear I will screw up the servo on it due to the weight.

I made that comment in regards to my SP10MKII - any comments / advice with your and others MKII experience ?

Thanks Chris

Chris.
Quite a few of my customers use after market metal mats. SS and CU.
This adds considerably to the moment of inertia of the platter, but none have had any problems that I am aware of.
My own custom platter is the same weight but a slightly higher moment. Again no problems.

Slaw
I very much look forward to reading about your TT project.
As before I agree totally that things need to be true. If you are controlling the whole process and have access to a good machine shop, this should not be difficult.
My TT and Pre happen to sit on granite surface plates, surplus left overs from our machin shop. They are used, not of their flatness but their energy sinking properties.

If you are going to pod the arm, is it necessary to retain the standard arm/ plinth arrangement? Could you machine the arm pillar and pod as one piece? Some would argue that multiple paths to the plinth (pod) can be problematic. Maybe have the final adjustment of the arm's trueness set by the pods feet? Just a thought.

I have fused my custom arm pillar to the plinth with a solvent that actually melts the surface of the acrylic. The vendors of this stuff claim that the result is a homogenous material as strong as the parent. Thus the pillar and plinth are effectively one. I retained the ability to correct any dimensional errors since the whole plinth could be machined with the arm pillar attached.

I'm sure that your project is going to be a lot of fun and produce brilliant results.

Ct0517 - I have listened at length to several SP10's both MkII and Mk3 both with and without the krebsupgrade. To my ears none of them are particularly transparent. Both the Micro Seiki 5000 ( air bearing ) and Ipad (on BDR cones with Cambridge 840 DAC ) sound more resolving, more fluid in terms of timing and have an openness that eludes the Technics.
Re the mats - I've compared the std, stainless and copper and preferred the copper - a bit more focus and cleaner through the mids. The Mk3 is substantially better than the MkII - less jittery and grainy, but bear in mind the Mk3 platter is considerably heavier and more damped than the MkII. In my view playing around with mats on the MkII merely highlights its shortcomings, and you may be better off with something relatively benign rather than resolving.