Eminent Technology ET-2 Tonearm Owners

Frogman - BTW, the Forsell still sits in the box (es) :-(

Frogman - this indicates to me that you are happy with the current set up. enjoy the music :-)

fwiw - I find it very ironic and kind of funny actually that your Forsell, and my JN Lenco, two highly praised tables from a particular bloggers webage, lie in storage..... albeit for different reasons. Fascinating hobby.

LK - VdHul silver wires, a little stiff from what I can gather

imo - stiff for this ET2 air bearing application - not great. In another air bearing application where the design needs the wire to resist a little for damping - another story. Which do you feel is a better design ? Stiff wire inside a speaker cabinet - not a bad thing.

my experiences - Braided unshielded wires help to resist RF, which is a good thing. But the wire itself become very unruly with a mind of its own when braided and asked to curve just a little. This can become a real PITA real fast. Where it leaves the armtube my wires are separated like strands of hair. Their physical resistance is cut by at least half by doing this. Each wire is then tested for RF individually. Preamp muted, lower the stylus onto a still record, unmute your preamp phonostage turn the volume up - move each wire around until things are quiet. Hold in place with blue tack.

Look forward to your impressions LK.

Cheers

New member of the owner's club here. I'm a bit confused by mine though. Do I need a special turntable?

I'm a (very) long time user of the ET2 arm, I owned the ET one before. I still find the arm superb!
I have a first comment, others might follow.
The question of resonance frequency is mostly re-cycled from some sources, that did a lot of calculations a lot of time back. That's OK, but there is one aspect missing IMO.
The main signal is cut laterally, one can safely assume that if there are very low frequencies on an LP it is cut *laterally*. The main disturbance laterallyis off-center records (0.55 Hz).
The off-phase info is cut vertically. The off-phae low frequency part is not doing anything helpful in normal rooms, so usually the LF signal below ca. 100Hz is blended to mono.
This leads to severely different optimal resonance frequencies horizontally and vertically. More will follow.
Let it be said that my most memorable analog experience in the 70's was a FR64 & FR7 combo - it had *decidely* "suboptimal" resoance frequency, ie. far below 10Hz. It sounded better than anything else I heard at that time, and I still the *bass" and ambience of that front end. There's a physical reason for it, I think.

I remember this combo clearly because it was visible that it had rel. low damping and an unusually low resonance frequency. I knew and was used to tonearm/cartridge combos with "correct" resonance frequency. This one was incorrect - and sounded better than anything I had heard (in the low-mid frequencies, in dynamics and resolution).
If "correct" resonance frequency would be the main reason for optimal or non-optimal sound, such suboptimal resonance frequency should have almost destroyed any potential of good sound. (that's what I thought then).

The normal warp & rumble zone is usually quoted between 2 to 5Hz - it leads basically to vertical accelerations. If one assumes that there are no important signals to be traced below 20 Hz or even below 50Hz (because the big excursions involved in low freq. creates problems for the cutting head *and* the cartridge. And because even in big listening rooms it is difficult to reproduce phase differences in LF) one places the optimal *vertical* resonance frequency between 5 and 20, or more radically even below 5 and 50Hz.
-> Vertical optimum is around SQR(5x20)=10 Hz or even SQR(5x50)=21 Hz
(so long so good, so often heard).

Horizontally there is a main disturbance at 0.55Hz (33.333rpm/60"), maybe 0.75 Hz (45rpm/60"). But there is a good reason to extend extraction of musical information like ELF reverb etc. down to at least 5Hz - if possible. Cutting and manufacturing LPs has several modes of creating vertical disturbances but only one or two horizontal issues: Off-center records (which actually could and should be corrected) and horizontal bumps on the cutting lathe - rare (but I have one such record in thousands of LPs).
So there is a moderate, but constant excitation/acceleration on 0.55Hz (basically correctable) and a useful extended LF range down to 5Hz which leads
to an
-> optimal horizontal res. frequency of SQR(0.75 * 5) = 2 Hz

I agree that low horizontal res. frequency is not without problems (with highly off-center records). But preventing this problem with much higher (ie. standard) horizontal res. frequency means loosing very worthwile ELF information (which, as said above, is cut mainly in the horizontal plane.)

So the *often" alluded main "achilles heel" of air bearing arms is actually an advantage, in an "objective", physical sense. About the same time, I drew these thoughts up on paper, I found the new Mörch arm which does *exactly* follow these reasonings, with superb result. It couples the cartridge to a *very* high horizontal mass. Experiments show that the rigid coupling of that horizontal mass vs. the cartridge is sonically important.

The ET 2(.5) and other air bearing arms have the same high hor. mass advantage "built in for free".
The decoupled counterweight of the ET 2 gives simply more freedom with problematic pairings of cartridge, arm and off-center records.
Maybe, when it is not necessary, blocking the decoupling could have advantages sound-wise.

BTW in my experience it is extremely important to have both the platter and arm *extremely* well levelled in the horizontal plane. Side-forces on the cartridge cantilever lead to plummy bass. Probably because a variable pull with varying tracking friction on a laterally deplaced cantilever gives dynamically varying side forces - which might energize the horizontal resonance. It sure is very audible. In my setup it is important to check regularly, floating the arm with two equal blobs of Blue-Tak on both sides of the arm, one at the backside of the arm, the other on the counterweight.