Eminent Technology ET-2 Tonearm Owners

"you misunderstand how it works".

Not so.

Please reread my post.

I was referring specifically to the static effect - hold a magnet near apppropriate metal: does it have zero effect?

Of course much more important is what effect do these eddy currents have - must have negative effects. Has it ever been objectified ?

Thanks for your post. j

Very entertaining Chris, much mirth.

"I took one of the small circle magnets from the ET2.5 setup over to my Dynavector tonearm. What followed kind of reminded me of one of those horror movies –you know the one where the guy wakes up and finds himself magnetized in a kitchen; pots and pans, knives start flying towards him getting stuck on him as he ducks.

ok - no pots and pans or knives here. But I did LOSE the magnet as it flew out of my hand. I had to search to find where it had lodged itself."

"I am contemplating a post grad course in pseudo science"

So you've already graduated/excelled in pseudo science.

“para 1 - not obvious to everyone.”

Why not, there are only 2 words to understand: ‘modified ET2.’

“Adding lead mass creates higher inertia but does NOT retard motion.”

Yes it does, more energy is required to activate the system.

You’re banging on about lead mass and inertia as though it is a random activity.

Required mass (and its related inertia) will be cartridge specific, so isn’t it simplistic to state or imply that no mass should be added to an ET.

Can you please advise (and of course fellow posters) what speakers you were using in your system when you set up the loose counterweight decoupling method.

I am interested in this approach and its effect on the sound, particularly in the bass region. Thank you.

For clarity: the question in my last post was addressed to Mr Dover.

Bruce Thigpen:

"The ET-2 with the
damping trough will exhibit almost perfect low frequency phase response."

You don't like the ET-2 set up to have near perfect low frequency phase response?

Thats fine, its a free world, but it means you accept/enjoy DISTORTION.

BTW, as you haven't run an ET2 for heading towards two decades, isn't your credibility suspect?

"..... do not appear to grasp the physics and engineering principles involved."

MF wasn't speculating when he heard 1 of the best 2 arms in the world - I guess you'll never be able to look out the door and see blue sky and appreciate that (the Kuzma is just about the best arm on the globe, dispite it contravening your design principles ..... uuuuuuuuuuuum how many arms have designed and manufactured?

I hope Franc Kuzma casts an eye over your 'advice' to correct his fauly design.

Put on your knitwear cardy so don't catch a cold, your thick lensed glasses so you don't fall, then pop out and replenish your Prozac.

Chris (such a lovely guy):

"You come across as a real hard ass .."

Acronym: PITA

BTW did Richardkrebs pick on you at preschool?

Not an audiophile! Never mind.

But I do know what 'diatribe' means:

"A forceful and bitter verbal attack against someone or something."

Utter Nonsense Dover, and I quote you

"What Bruce Thigpen actually says on his website .......... 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."

It would have been useful if you had done engineering.

The peak is at the resonant frequency, not 3x Fr.

Dover wrote:

"This is nonsense Richard. Your comments that the air bearing is rigid defies physics. Have you heard of compressed air. You can get 2300l of air into a dive bottle with an internal volume of 11 litres. Try that with metal.

Why not try to compress 1 litre of metal into a 50ml can at audio frequencies. According to your thinking this is possible.

Do you get any of this?"

The writer should get this, from Franc Kuzma:

'At hi-fi shows, we routinely ask people to pull or twist the Air Line tonearm on a Stabi Reference turntable. The whole suspended mass of 24kg (52.8 lbs) moves back and forth for 1/4!9 while the air bearing maintains zero friction! Most people are shocked.'

Pseudo science from Dover:

"removed their fluid damping and replaced it with electromagnetic damping which has the benefit of not inhibiting movement until the movement happens."

Pseudo science: its identical with fluid damping - there is no damping unless there is movement (same with the dampers, so called shock absorbers, on your car. Drive slowly over a speed hump and the whole vehicle is raised, ie there is no movement, and no damping).

Slaw
"I have to say that as regards to using acrylic as a platform for the vinyl record ......"

Further reading, TAS 40th issue.
Wayne Garcia on the new Rega RP8:

"Most notable is a two-piece, 16mm thick flywheel platter made of float glass, a technique wherein molten glass is Floated over molten tin in order to create the flattest possible surface and overall uniformity of thickness. To form the flywheel platter, Rega joins two separate pieces of float glass to the underside .... adding mass to the circumference.

Damn marvellous I say!

Oh dear, Andy Payor doesn't know what he's doing either.

He's just added distortion by incresing the weight of his arm.

The world according to Dover.

Re the 'Audio' review. When you call up the pages on Chris's site, I've been alerted to what can be confusing.

Call up one of the pages, then hit the + button at the bottom right of the page TWICE, and readable it will be.

'Audio' review of the ET-2. Excellent read with some (if you haven't already read it) surprising, even startling, results. By Edward M Long in 1987, when reviews were a serious affair.

As I'm semi literate, Chris has kindly uploaded my jpegs to his site. Thankyou Chris.

Go to

http://s1173.photobucket.com/user/CT-993/library/?sort=2&page=1

(it works, I've tried it) and you will find 7 pages of review, including v interesting measurements.

I did try to post this review here, but that cann't be done presently.

Sorry guys if this duplicates an earlier ET-2 post. I haven't read every one of well over 700 posts.

'Audio' review: further to my comment about enlarging individual pages on Chris's site.

I've found it better to use View(Toolbar)> Zoom > Zoom In, and Ctrl + or Ctrl-

Dover has repetitiously stated richardkrebs ADVOCATES adding lead mass to ETs

This is incorrect.

Mr Krebs openly told the forum how he sets up HIS arm for his LOW compliance cartridge, and the reasoning behind it.

He (RK) suggested others could try it to educate/inform themslves, adding to the collective knowledge of posters, because IT IS EASILY REVERSED.

RK has not tried to CONVINCE others to follow his setup.

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

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

Yes indeed Chris, that is a time honoured method, and can satisfy oneself.

But not Dover - it lacks 'science and concrete evidence.'

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.

Chris: further to your comments on changing to the magnesium wand.

According to Dover, what you heard was meaningless, unless the system was described at the time of testing - it could have been due to colorations elsewhere in the system.

Additionally, without science and concrete evidence, its useless 'just' describing what you heard.

“If the goal were to keep the cartridge still, then one would never reach the end of the record.
The record groove is not a straight line; it is a spiral with a decreasing radius that requires the cartridge to move to the center of the record as it plays.”

Mumbo Jumbo from Dover.

When you ran these same arguments months ago I suggested you drive quickly over speed bumps and see whether you need damping.

Better still: disconnect one end of the rear dampers of your car (not difficult to do) and drive quickly over speed bumps. Tell us whether you need dampers. Remember to fasten your seat belt!

Dover
"Loading the tonearm with mass, as Richardkrebs has advocated, increases inertia, and as the groove moves in and out, the increased resistance to lateral movement means that the cantilever will flex more and the measurement of the groove modulation will be impaired and inaccurate.

This is the fundamental principle upon which Bruce designed the LOW mass, decoupled counterweight ET2. Richardkrebs in this thread has advocated converting this tonearm into a very HIGH Mass arm. He also advocates removing the decoupling. These alterations add 60g to the effective mass of his ET2, increasing inertia and resistance to lateral motion by over 300% compared to a standard ET2.

These gross alterations will result in destroying the inherent advantages that the LOW mass ET2 offers in
superior tracking and minimising distortion."

This is what you wrote on date xx ..... take your pick.

Repetition is the sincerest form of flattery.

Why do you keep (repeatedly) trying to prove the arm designer wrong?

Dover: lack of response by yourself was not noted.
Further, whispers suggest all here join with you, and hope that any further neurosurgery you have is successful.

Dover wrote:

".... Bruce goes through a design process, supported by principles of physics and sound engineering, includes mathematical modeling, the production of prototypes and thorough documented testing before his products go to market. There is no speculation or guesswork involved."

You say "I agree with Bruce's observations."

Please advise what testing you have done to arrive at that conclusion.

It should be verifiable engineering: no speculation, guesswork, or internet regurgitation will suffice.

Oooooooooooooh no - you omitted the dayglo label!

Dover
Having a titanium arm tube sitting around somewhere unused, you must be highly satisfied with the one piece gooseneck a la Krebs, and aluminium armtube.

What difference did you hear when you went to a one piece gooseneck a la Krebs?

Give me a convenient time and I'll come round and photograph the titanium wand: many will be interested (you could also let me know how much you want for it).

Chris, google isn't as good as it used to be: it hasn't brought up a chartreuse key with a dayglo (bright) label attached to the short end reading ... HOLD HERE.

Dover, please advise what colour Allen key Ct0517 should use.

"By the way in your original post you suggest using the short end of the allen key - in fact using the long end in the cap screw, and turning the short end to turn will put less torque on the bolt." Dover

“Magnetic dampening will vary with the speed of horizontal motion whereas the added mass approach is simply increasing static inertia considerably.”

"The magnetic dampening only commences its action once the arm starts moving, and is proportional to the rate of movement. I should point out that the dampening is created by eddy currents which are only generated when the arm moves relative to the magnet."

How was no static magnetic effect achieved: did you switch off the magnet?

After a week in Australia for F1 racing, I checked this thread.

Surprised I was, that it continues: high horizontal/lateral mass wrecks cartridges (words to that effect), or at least Richardkrebs arm setup does (words to that effect).

It catalysed me, finally, to read Michael Fremer’s review of the Kuzma Air Line Tonearm.

I figured as Franc Kuzma uses significantly MORE horizontal mass than Richardkrebs with his low compliance cartridge, Mr Dover would implicitly conclude Kuzma doesn’t know what he’s about, selling a defective design.

Well, revelation: Michael Fremer says (after initial academic objections to the design)

“Ultra-black backgrounds; enormous, airy, startlingly stable soundstages; palpable images perfectly placed and sized; ear-popping harmonic, dynamic, and transient complexity—I could blather on about the Air Line's convincingly natural performance and brilliant overall balance.
I'd rather just get to the point: In every playback parameter I was able to delineate, the Kuzma Air Line's presentation was staggeringly better than that of any other arm I've auditioned—with the exception of the one included with the $70,000 Rockport System III Sirius.”

“With the addition of a damping trough, the Air Line could very well be the finest tonearm ever built.”

Mr Kuzma replies to MF

"A question of damping..."
A system will resonate only when disturbing forces appear at the resonance frequency. If there are no disturbing forces, then there are no problems. However, if a system is overdamped, then instead of one resonance, two smaller resonances occur, one below and one above the previous resonance, which can create further problems. There is, in fact, a level of effective damping on the Air Line tonearm. The cantilever suspension, and the air supply tube add damping. Our choice was for either too little or adequate damping; we chose the latter.

"Eccentric LPs and any deviation from absolute horizontality will create...problems..."
Horizontal disturbances of an eccentrically spinning record occur only at 0.55Hz or 0.75Hz (33rpm or 45rpm). This is well out of the Air Line tonearm's resonance in the horizontal plane, which is between 2 and 5Hz and does not cause problems tracking virtually all LPs. Plus, if one has a defective disc so poorly pressed or off-center that it might cause such problems, it is perhaps most prudent to simply not play it.”
(Sorry guys if these comments are already part of the thread).

After such a classy weekend I cann’t energise myself to provide a series of theoretically derived, professorial quotes.

It is self evident Franc Kuzma is the real deal, producing superlative product with inherent sonic performance at the far end of world class designs.

Suffice to say Franc Kuzma can be trusted to confidently illuminate the subject.

The same cannot be said of Mr Dover’s bombastic contentions.

Hi Chris

“Can you guys recommend a good cabernet sauvignon from ‘downunder’ that will not break the bank and is safe?”

After decades of research (not backed by multiple degrees mark you), I can offer an opinion that might help (I won’t say satisfy, as one man’s wine might be another man’s poison, thus safety not guaranteed, but works for me!

We (myself + TSO - The Significant Other), are fond of rich, fruity, gutsy Australian reds. Gutsy, as in full bodied – I can’t bear rough stuff.

What has become a staple is Taylors Shiraz, preferably 3 to 5 yrs old (if you can keep your mitts off it that long) and warm, not cold, temp wise. Don’t sweat over, ‘Oh it’s not Cab Sav,’ we’ve drunk a lot of that also.

Warning: you will enjoy life a lot more.

Whether your arm is lead augmented, or made of balsa wood or unobtanium, or setup according to celestial directives, becomes less important. You will not be very likely to write epistle length diatribes.

BTW, so you aren’t confused in future, I’m thinking of acquiring an alias (false name): BenDover.

The writer, Dover, has written a great deal about air bearings lack of rigidity on this thread.

A few comments:

“In the Hifi News Review of the ET2 Martin Colloms concluded that the shape of the resonance passing through the air bearing remained intact.
This is not per se empirical proof that air bearings are rigid.”

Prove your assertion, thank you.

“Air bearings have compliance, and gimbal bearings can only be too tight (loaded) or too loose and can chatter.”

“The response above to my original post of 04-17-13 contains misinformation.
The comments plucked from the internet are irrelevant as they pertain to ball bearings and air bearings.”

Why is information on air bearings not relevant to discussion of air bearings?

“Unipivots are mechanically coupled, whereas an air bearing is not rigid and loses some of the leading edge.”

You have proof?

“So one could surmise that the Kuzma does have a stiffer bearing if you accept that Bruce Thigpen knows what he is talking about, which I do as he is well studied in Physics, Maths, Audiology and has been designing air bearings for some 30 years.”

Your statement regarding Bruce Thigpen is equivocal.

I suggest you contact Bruce Thigpen directly. Tell him you are the poster on Audiogon who has been promulgating the lack of rigidity of air bearings.

Ask him why he designed a floppy bearing and POST THE RESPONSE HERE unedited. Thank you.

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.

Slaw
"I do agree with Fremer that this (acrylic) isn't the best material for great transient response, tight, controlled musical bass @ realistic sound that I crave."

Interestingly, last night, I stumbled on the following comment re the VPI Scout 1.1 platter (Joel Salcido, TAS 40th anniversary issue): This one is Not acrylic and to hear Harry (Weisfeld) tell it, acrylic platters are a thing of the past. It's simply easier to machine metal to tighter tolerances, and the fact they sound better ices the cake.

Back in the Goldmund days, I understood their acrylic platter was for optimum impedance matching (with vinyl). Life moves on huh.

Dover, you wrote regarding Richardkrebs (and Chris/Ct0517 when he changed to his magnesium arm wand, as they used the same methodology) ....

"I see very little science and no concrete evidence to support your observations."

With all due respect, would you please articulate what 'science and concrete evidence' you apply in similar situations.