Eminent Technology ET-2 Tonearm Owners

Hi Richard

" spring cleaning ? "

I wish. its freezing here.
where to put the Christmas tree for best room acoustics in a shared room ?

I am interested in your I Beam testing/findings.

Is your manifold a standard low pressure one ?
If so consider including tests that use just enough PSI to make the spindle float and work as Bruce designed.
I think Dave's recent observations on music presentation when PSI is run higher on a regular LP 2.0, show how much we change change things up with PSI. This will change your findings/results.

I am also interested to know what your and others definition is of a really eccentric record ?

I believe we are all different in what we will tolerate as far as this is concerned.

Wouldn't it be nice if someone came up with a record making machine that could produce holes in vinyl - LIKE A CD.

Looking at the way the groove looks.

http://embrangleroot.files.wordpress.com/2012/08/tumblr_m7ob01afye1qlixleo1_1280.jpg?w=614

Now add an off centered hole to that mess.

Chris.
Yes spring has sprung here. BBQ's, Boating, Fishing, and company with great friends watching long sunsets over a glass of wine. I suspect that it was the change in temperature that precipitated the o"ring failure.
I am using a HP manifold at around 18 psi.

HF Dover.
I knew that you would bring up the added weight question inside the spindle. The 30 gm adder was a guess based on 16 year old memory. Clearly my guess was well overstated. I will be removing this when I do the swing arm counterweight test to bring the arm as close to stock as possible. The 95 gm total, arm and cart weight, is accurate. This depending upon c/weights and cart used by others, being more or less the same as a standard ET2 using a mag wand.



For further discussion on how every ET2 on the planet requires the cartridge to push sideways the total arm weight when tracing an eccentric record, please read below....


> Bruce.
> I have been thinking about the horizontal effective mass of your ET2 and have a question please.
> The horizontal effective mass calculation you give in the tech section of the manual shows an arm mass of 30 grams which is then added to the weight of the cartridge to give total horizontal mass. This calculation ignores the weight of the counter weight since it is decoupled via the leaf spring.
>
> My question is around the horizontal effective mass seen by the cartridge when tracing an eccentric record. The resonant frequency of the counterweight spring assembly is 2-5 hz and the lateral tracing frequency of an eccentric record at 33 rpm is 0.55 hz.
> At 0.55 hz the transmissibility would be approaching 1, even with a counter weight spring frequency of 2 hz.
>
> This would therefore mean that the cartridge "sees" all of the counterweight weight when tracing an eccentric record?
> Thus the effective mass at this low frequency, 0.55 hz, would be the total weight of the arm and cartridge including the beam and the weights it is carrying.
>
> Many thanks
>
> Richard.
>
>
Richard,

Below the counterweight decoupling frequency cutoff ~ 2hz, the effective mass becomes the total mass. Then you have another resonance freqeuncy to add to the mix which is typically much greater than .55Hz.
So yes, it sees all of the mass below 2Hz, but the combination of those masses results in a cantilever resonance above that frequency. You should see the arm move back and forth with the eccentricity of a record at .55Hz as opposed to deflection of the stylus.

I hope this helps and thank you very much for the interest.

brucet

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

Chris,
We are children of the revolution, the swirling 1960´s and we "speak" the same language. We have certain respect to our past, and it´s music itself. The super groups we listened when we were kids will be our musical heritage till the end of time.
The turning point for me personally was in 1974 when I used to listen FM radio and I occasionally managed to record some strange and quite extraordinary music to my PHILIPS radiorecorder (at the time I didn´t have a record player !) I captured "Shine on Brightly" by Procol Harum, "Meddle" by Pink Floyd, "Brain Salad Surgery" by ELP and "Starless and Bible Black" by King Crimson on tape. And "Twin Peaks" by Mountain as well, probably the heaviest/fattest bass sound ever put on vinyl. Thanks to Felix Pappalardi, the great late producer, band leader & musician. Of course, we kids listened the pop music too.
But I hadn´t any idea where this all will lead in next year. My dear dad bought me my first stereo system. The finest part of the sale was a bonus, the double album "666" by APHRODITE´S CHILD, would you believe ! Oh yes, the mighty music composed by Vangelis & sung by Demis Roussos who has a very unique and beautiful voice. This stunning music blew this kid´s mind away and never looked back ever since.

But it still took 26 years to find another musical treasure hidden in time, the fantastic Classic Italian Progressive music. In 1973 Alphataurus the Mighty Dove abandoned manking in frustation & anger because of commersializing the music culture. But mankind still has hope as we saw the triumphant return of Alphataurus in 2011 as documented in "Alphataurus Live in Bloom"

http://www.ebay.co.uk/itm/LIVE-IN-BLOOM-ALPHATAURUS-VINYL-NEW-/370760653864?pt=UK_Records&hash=item56530e9c28

And resulting a Renaissance in Prog Music, especially in Italy after all the years ! Another gem:

http://www.btf.it/dvd/prog-exhibition.html

Another thing I regard you as a sir is your TT, The Platine & ET-2. I think it´s a very special combination. In fact, you are running a double air suspension system turntable truly.
This unique and very sophisticated techique you are using proves that you take audio and music VERY seriously and you truly respect the things you love.

Furthermore and as for an extra suspension, I would suggest you to try a Reso-Mat made by Vic himself. IME over the years it is a true bargain in audio. In my system the improvement in audio guality & quantity is really huge.
It´s due to it´s feature that vinyl sits freely and uncompressed on vinyl spikes that allow resonances vanish into air and not bouncing back to vinyl and rearching stylus. Many things in mechanics are simple, also this. It works !

http://www.ebay.co.uk/itm/RESO-MAT-TURNTABLE-PLATTER-MAT-FOR-TECHNICS-SL1200-GARRARD-401-/181111989567?pt=UK_AudioTVElectronics_HomeAudioHiFi_Turntables&hash=item2a2b1da53f

Btw, thaks us showing the way to the record groove, I actually haven´t seen it so clearly before ! What a revelation !

Cheers

Harold-not-the barrel.
Absolutely agree with your eloquent post. You did forget to mention Jethro Tull though :-)

Although I have not met Chris, it is clear to us all that he is passionate in the extreme about his music and is a gentleman.