Eminent Technology ET-2 Tonearm Owners

Richardkrebs
Also it is made from the same grade of aluminium as the spindle, 6061 T6. This to minimise the different material count in the arm loop.

A correction to my earlier post regarding the make up of the ET gooseneck. The ET armtube insert is aluminum as well. The joint itself is Carbon Fibre. Sorry for the error.
Both Richard's and Eminent Technology versions can be seen
here

Ok I think my eyes are doing funny things. I admit I saw and read a couple posts now in the last couple of weeks here - only to see them disappear? I have heard similar things about this phenomena on the MM thread. But there the posts never made it.

I know we are all big boys here and can handle whatever controversial topic comes up but maybe we have reached tolerance levels with the moderator? I think we still can have robust debate. Maybe we just need to be a little careful with some of the words we use. Just a thought.

Or maybe it is my eyes and I should switch to South African wines from Australian for a while? Good thing this hobby is based on hear and feel.

Cheers

Why your Brain Craves Music

A warning up front – the author does not care whether we use a spring or not. And his main music source is Spotify.

By Dr. Mercola

If you’re a music lover, you already know that turning on the tunes can help calm your nerves, make stress disappear, pump up your energy level during a workout, bring back old memories, as well as prompt countless other emotions too varied to list.

Even if you’re not a music aficionado, per se, there are compelling reasons why you may want to become one, which were recently revealed by a series of new research.

Music Prompts Numerous Brain Changes Linked to Emotions and Abstract Decision Making

When you listen to music, much more is happening in your body than simple auditory processing. Music triggers activity in the nucleus accumbens, a part of your brain that releases the feel-good chemical dopamine and is involved in forming expectations.

At the same time, the amygdala, which is involved in processing emotion, and the prefrontal cortex, which makes possible abstract decision-making, are also activated, according to new research published in the journal Science.1

Based on the brain activity in certain regions, especially the nucleus accumbens, captured by an fMRI imager while participants listened to music, the researchers could predict how much money the listeners were willing to spend on previously unheard music. As you might suspect, songs that triggered activity in the emotional and intellectual areas of the brain demanded a higher price.
Interestingly, the study’s lead author noted that your brain learns how to predict how different pieces of music will unfold using pattern recognition and prediction, skills that may have been key to our evolutionary progress. Time reported:2

“These predictions are culture-dependent and based on experience: someone raised on rock or Western classical music won’t be able to predict the course of an Indian raga, for example, and vice versa.

But if a piece develops in a way that’s both slightly novel and still in line with our brain’s prediction, we tend to like it a lot. And that, says [lead researcher] Salimpoor, ‘is because we’ve made a kind of intellectual conquest.’

Music may, in other words, tap into a brain mechanism that was key to our evolutionary progress. The ability to recognize patterns and generalize from experience, to predict what’s likely to happen in the future — in short, the ability to imagine — is something humans do far better than any other animals. It’s what allowed us (aided by the far less glamorous opposable thumb) to take over the world.”

To read more

Air Bearing Stiffness

Richardkrebs

Stiffness

Many years ago I remember reading an audio magazine which tested the rigidity of the ET2 bearing. It may have been Martin Colloms, but I can't be sure. This was done, again from memory, where accelerometrs were used and a sweep frequency was applied to the spindle. The result showed a bearing that was stiff at audio frequencies.

This is explained by the design of the bearing (it's self centering characteristics) and its extremely high resonant frequency. Many times higher than the audio spectrum. Although the bearing uses air which we know to be compliant, at the frequencies of interest, the bearing medium is stiff.
I also show here a quote from an industrial air bearing manufacturer. While these a big load bearing devices, their design is virtually identical to the ET2

"Outstanding stiffness for small deflections Most engineers visualize an air bearing as being like a hovercraft, and they erroneously conclude that a bearing which floats on air cannot be very stiff. Actually these gas bearings are many times stiffer than a ball or roller bearing. Sapphire orifices within the bearing gap control the pressure in a film of air which is only 0.0003 inches thick. As a load is applied to displace the bearing rotor or slider, the gap decreases very slightly on one side, reducing the flow of air through the adjacent sapphire orifice. This results in a pressure increase in the gap on this side which pushes the rotor back to its original position. In essence, the air bearing is a servomechanism with closed loop control, and maintains a uniform gap in spite of external forces that may be applied. This results in bearing stiffness of millions of pounds per inch for small deflections. Stiffness is linear and does not change with temperature. In contrast, ball or roller bearings have almost no stiffness unless heavily preloaded. The stiffness of a ball bearing is not linear, and varies considerably with temperature."

Richard - thanks for providing this info - the part that hits home with me.

“This is explained by the design of the bearing (it's self centering characteristics) and its extremely high resonant frequency. Many times higher than the audio spectrum. Although the bearing uses air which we know to be compliant, at the frequencies of interest, the bearing medium is stiff.”

I usually hear only about audio designers trying to come below the audio spectrum – especially with a TT setup ?
That is what the conversations have been based on here as well ? 2hz – 6 or 7 hz.

This is truly outside of the box. Dover mentioned somewhere on this thread a while back that testing of the resonances with the ET2 seems to just pass through it ?

Dover - was this the same study? Maybe the test gear was not good enough to capture this info. I mean - its parameters setup for human hearing.

"Many times higher than the audio spectrum" I guess this explains why my dog does not start howling when I play music. Its beyond him as well. ...

Regarding leading note edge performance. My reference in my room are master tape dubs. No issues here with the air bearing.