Eminent Technology ET-2 Tonearm Owners

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.

John47,
my name is Dover, not Utter Nonsense Dover. I have in fact studied engineering and English as well at university.
Please see below the difference between “a” and “the”

"a" [uh; when stressed ey]
indefinite article
3.another; one typically resembling: a Cicero in eloquence; a Jonah.

"the" [stressed th ee; unstressed before a consonant th uh; unstressed before a vowel th ee]
definite article
1. (used, especially before a noun, with a specifying or particularizing effect, as opposed to the indefinite or generalizing force of the indefinite article a or an ): the book you gave me; Come into the house.
2. (used to mark a proper noun, natural phenomenon, ship, building, time, point of the compass, branch of endeavor, or field of study as something well-known or unique): the sun; the Alps; the Queen Elizabeth; the past; the West.

So, in the context of a “resonant peak” “a” does not represent “the”.

Do you know what PSI and Pump type your ET2 or ET2.5 was designed for ?

3.6 PSI - Original Takatsuki and ET-2 or 2.5

5.0- 7 PSI - WISA 300 air pump and ET-2 or 2.5 with high pressure manifolds

>10 PSI - users with shop compressors and ET-2 or 2.5 high pressure manifolds

Note, if the pressure readings are higher than those listed above, the manifold could be clogged, if the pressure readings are lower, this suggests that the pump may not be performing correctly.

(Taken from Bruce's website)

What other thread allows us to learn about fine wine from downunder and good English ?

Well I did enjoy that youtube video Dover. Not surprising that not much has changed with the actual record since 1958 when the film was made. I could say they don’t make records as good anymore....anyone disagree?
In 1958 - I was just a thought in my parents eyes till four years later. Does anyone listen to music in a shirt and tie anymore?

At the 4:40 mark is an excellent example imo of a speaker setup. Nearfield and eliminating room problems by taking the room out of the picture. I love those speakers spikes. We can learn lots from these films.

The fellow talking reminds me of my Grade 8 science teacher. The guy in the film does show a bit of a smile at the end however. My science teacher in middle school was a German fellow that never smiled.

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.