Eminent Technology ET-2 Tonearm Owners

Dover.
I quote directly from your post of 03-13-13

*********On an eccentric record the acceleration will be the same for each arm –
0.0024metres / (1.8 sec x 1.8sec) = 0.00074 metres per second squared

The horizontal effective masses of the 3 arms mentioned in this thread are:

Kuzma has been quoted as 100g
Terminator 80g
ET2 25g

The force on the cantilever is as follows:

Kuzma = 0.1kg x 0.00074m/s2 = 0.000074 Newtons
Terminator = 0.08kg x 0.00074 m/s2 = 0.000059 Newtons
ET2 = 0.025kg x 0.00074 m/s2 = 0.000018 Newtons

Summarising then you can see that the increased mass of the Terminator and Kuzma arms increase the lateral forces on the cantilever by 300-400% over the ET2.

Now Krebs has modified his ET2 by adding 30gm of lead to the spindle. This adds 30g to the effective mass of the "ET2. Krebs also couples the counterweight ( no spring ) which adds another 30g to the horizontal effective mass.

So Krebs has increased the horizontal mass of the original ET2 from 0.025kg to 0.085kg.
The Krebs modifications have increased the lateral forces on the cantilever by over 300%**********

Dover
You stated in this post that the ET2's effective mass as seen by the cartridge WHEN TRACING AN ECCENTRIC RECORD was 25 gms.

This is not true. The effective mass of an ET2 below FR is the total mass of the arm including the weight of the counterweight. Depending upon cartridge and wand used this will be in the order of 75 to 95 gm. I say again, the leaf spring does not flex due to the action of tracing an eccentric record, so it does not lower the effective mass at these frequencies. The lateral forces imposed on my cartridge due to tracing an eccentric record are much the same as those imposed on a cartridge mounted in a standard ET2, Terminator and Kuzma. If the cantilever is flexing when tracing an eccentric record in my set up it is by definition flexing with a standard ET2 as well.

I am sure that others are finding this line of discussion tedious and for that I apologise.

Slaw.

Thanks for the info. I will take a look at M-30 M-60. Does this have an air bleed as well? I am already using a combination 3 micron filter and water trap.

Richardkrebs,
You are wrong. You continue to put up an argument for adding lots of mass to the ET2 and removing the patented decoupling methodology of the counterweight. Your argument is based on a strawman hypothesis that only focuses of frequencies below FR. Bruce Thigpens exhaustive testing does not support your view. You continue to ignore what is happening above FR when the decoupling reduces the horizontal mass, and your horizontal effective mass is 300% higher than a standard ET2 ABOVE FR.

You claim that 300% higher horizontal mass above FR ( ABOVE FR ) and removing the decoupling is of no consequence. Bruce Thigpens testing that he has documented on his website clearly shows that you are wrong and the problems of increased resonance when the counterweight decoupling is removed are documented.

Your claim that high horizontal mass has no consequence suggests that Shure, Ortofon, David Fletcher ( of Sumiko ), Alisdair Aitken ( SME ), Bruce Thigpen and virtually every tonearm and cartridge manufacturer has got it wrong. Record grooves are cut at 45 degrees, both vertical and horizontal mass matter. You cannot increase horizontal mass ( ABOVE FR ) by 300% and expect no change.

In this thread Dgarretson has reduced the horizontal effective mass of his Terminator and yielded significant improvements in speed and resolution. Frogman has further decoupled his counterweight and yielded significant improvements in speed and resolution, more bass notes he says. I have tested fixed and decoupled counterweights some 30 years ago when the ET2 replaced the ET1, and yielded significant improvements with the decoupled counterweight even with very low compliance cartridges.

Bruce Thigpen has documented the problems of high horizontal mass as have Shure with their white papers on tracking.

None of your claims that a rigid counterweight and increased mass are supported by proper documented testing. Your argument is entirely based on theory, and it is flawed. Your maths that you quote continues to ignore the fact that the decoupled counterweight splits the fundamental resonant peak into 2 smaller peaks ( as demonstrated in the Stereophile review and Bruce Thigpens testing ) that has benefits of lowering distortion in the audible spectrum ( ABOVE FR ). You have used mathematical arguments that are not fully representative of the cartridge/arm resonant and tracking behaviour and are taken out of context.

I would suggest that you should buy a Kuzma arm which has been designed from the outset with a high Horizontal mass and has a fixed counterweight if you wish to throw away the advantages of the ET2 with its design goals of maintaining as low a mass as possible and minimising resonant peaks in the ultra low bass & minimising tracking distortion through the employment of the patented decoupled counterweight system.

Dover.
Sigh.... You need to read my posts properly. This is taking us nowhere.

Slaw.
I checked out the M-30 and M-60 filter. That is most impressive... 0.1 micron.
What regulator are you using? Testing with a small amount of air bleed in between my two filter regulators yielded strongly positive results. I suspect that this is due to some tiny instability in the regulators themselves.
I may experiment with a second bleed in between the last regulator and the arm. The arm should be a constant load, so bleed there should not result in varying pressure across the arms travel.

For those who desire the best and the perfect match for the ET2, there is a rare opportunity to purchase a Kondo Ginga TT for sale here on audiogon.

The Kondo Ginga is a derivative of my Final Audio Parthenon which is now unobtainable. In addition the Final Audio Parthenon has adjustable torque control of the motor and the SPZ base. I would expect however that the Kondo Ginga would be very close to the Final Audio Parthenon in offering unparallelled performance and resolution.
Having used the ET2 for a number of years with my Final Audio Parthenon, this combination is unsurpassed.
http://app.audiogon.com/listings/turntables-turntable-ginga-kondo-ginga-2014-02-05-analog-italy-irwin-oh
Disclaimer : I have no relationship with the vendor who is unknown to me.

Chris, you are a brave man opening up the proverbial can of analog vs digital worms. Perhaps the relative insulation of the ET thread will keep a discussion from getting out of control. The comments about square waves are very interesting, but it is not clear to me what, exactly, the author is trying to say. While I can't dispute his assertion that analog is unable to "reproduce" a square wave the way that digital can, I don't see that as a liability and take exception to the implication (as I read it) that analog is "warm" compared to digital as a result of some shortcoming or distortion; that it is less accurate. Additionally, the comment about the reason for this being, in part, the length of a cartridge's coil windings just doesn't hold water because, as you know better than most, the "warmth" of analog is found, even more so, in RR playback. It is true that analog is "warm" compared to digital. However, it is warm the way that real, live music CAN BE warm; it is not a distortion. It can also sound nasty and ugly the way live music sometimes is. Someone please tell me what I am missing here, but the author's comment: "Digital, especially MP3s, reproduce square waves like crazy. That actually upsets people! You’re triggering your fear, which also triggers fatigue. It’s unnatural." does not make sense to me. Does he not mean to say that digital "produces" square waves as they are generated by logic circuits in digital processing?

Now, before the arrows start flying, we all know that both analog and digital can sound very very good. But, to these ears, eventhough some digital playback can OVERALL (and depending on one's priorities) sound better that some analog, there is always a certain quality to analog that IN SOME WAYS, for me, brings it closer to the sound of real than even the best digital; and there is a certain quality to digital that, for me, always says DIGITAL (square waves?). Sorry if that offends anyone, but that is simply the way I hear it. It is not because of any bias, delusion or stubbornness, but simply a result of being around the sound of live instruments for hours practically every day; and my set of priorities in stereo playback.

Slaw, your comments about needing to always go "back to the music" and about "Nightfly" are right on and very apropos, but I am not sure what you mean by saying that some may be afraid of that. In fact, I would like to respectfully (and in the spirit of lively debate) take you to task. When I first mentioned "Nightfly" (quite a while ago) you felt that you couldn't listen to it because of its sound quality. To say that I was surprised would be an understatement due to my feeling that (especially for a digital recording) it was very good sounding and "fun" in a heavily-produced studio recording kind of way; a feeling shared by many. I am glad that solving some "room issues" now allows you to enjoy that recording, and I can only assume that recordings that were previously fine sounding are now simply spectacular. But, I guess that what "going back to the music" means to me is being able to enjoy the music even if the recording quality is less than stellar. I am having some trouble accepting the fact that your room was so problematic that it rendered that particular recording unlistenable. I will concede that the recording is clearly digital sounding, but it is not grating and has less of that typically digital quality that I would best describe this way: remember the old "Star Trek" TV show, and how when the crew would be teleported ("beam me up Scotty"), the image of the person being teleported would appear to be separated into molecule size dots before disappearing or reappearing. That's how digital images often times sound to me, there is a lack of completeness to the image density that analog seems to have even when there are deficiencies in other areas. There is also a completeness of rhythmic density (?) that gives music the warmth of human rhythmic expression and interplay that seems to be a challenge for a lot of digital recordings.

Thanks for the update on "Nightlfy", glad you are enjoying it and try to find Wayne Shorter's "Atlantis" for a wonderful analog recording in a contemporary jazz fusion (hate using that term but....) bag from one of the greatest player/composers of all time. Sealed copies are not difficult to find.