Eminent Technology ET-2 Tonearm Owners

Hi Mkieser! I assume you checked this, but in case not...
It's quite easy to upset the lateral balance of the arm while changing cartridges or arm wands. Did you carefully check levelness?I had issues with levelness even when using the VTA adjustment. So my recommandation is to always recheck for levelness after changing the VTA, or touching the VTA adjustment. And I think changing a cartridge or arm wand would apply for the same.
Horizontal off-levelness skews the tonality of the cartridge and deteriorates bass quality to a surprising the degree.
Another variable for somebody with a good aural memory is the tightness of all used screws and connections.IME lowest possible torque sounds best. I use only as much as to prevent slipping of the connections or the cartridge.
Your opinion might vary, but at least play and check these things.

Hi Chris & Dave! Funnyly, I watched through all the cartridge setup videos, and the long "testicles" video about cartridges inner qualities & problems the last three days. There is a lot of common assumptions and concepts about cartridge setup, and I have / had a bit of my own. Listening through Ledermanns videos is very inspiring and like a wave of clean fresh air into the brain. He is a f... genius.

Regarding azimuth I always wondered what to strive for when cartridge / cantilever combos of very expensive cartridges can be visibly off by three or more degrees - otherwise it wouldn't be visible. 
So the cantilever/stylus can be twisted in the body, and we can assume that it's probably difficult to get repeatable precision in production below 1 degree azimuth angle.
The second question then arises: How exact is the mounting of the stylus in reference to the moving coil armature, or (around the cantilever axis rotationally) non-symmetric moving iron or magnet structures?All this results in the question: Does the coil/generator needs to be aligned exactly with the groove, or is it the stylus?Ledermann gives a clear and IMO decisive answer. The left/right tracing lines / points should optimally be on equal height – specially with line contact styli there is not much tolerance. Optimizing crosstalk often ends in tracing the upper edge of one groove / channel and getting (sometimes a lot of ) additionnal distortion.
Optimizing channel separation symmetry (as a one parameter measurement) yields in that sense wrong results.
I used to align my cartridges with mono recordings, or mono signals. I had the cartridge mono-strapped with switched +/- connections on one channel. The problem with this setup is that  signal level differences between L and R result in less clear cancelling which gives a rather broad minimum. But interestingly in off-phase mono one can still hear the distortion more clearly. Maybe one should minimize *the distortion* in that setup. I got good results when keeping an ear on the distortion. Ie. minimizing the distortion and then in the minimum /optimal zone slightly adjust azimuth angle for minimal cross-talk.
Effectively one listens to the vertical signal in that setup (as in the Fozgometers reading) – with distortion appearing in the lateral signal because of suboptimal tracing in one channel, highlighted by the opff-phase setup.
I assume the Fozgometer has an optimized way to ignore the channel level differences and thus attainig a clearer null. But IMO doing adjustment by eye only on a meter eliminates the important audible changes. Ie. eliminating an important sonic parameter, the distortion, eliminates any remaining audible hint to tracing distortions due to stylus position.
Both the Fozgometer and the Feickert system align the generator vs. the recording instead of the stylus, and therefore they are misleading (to put it in diplomatic words). And they measure only one parameter instead of the more multi-dimensional listening process. 

IMO Peter Ledermanns talks are a must hear&see for any analogue/vinyl lover.

I agree that the ET2 has (probably) the only thouroughly intelligent VTA adjustment, though it isn't / wasn't without problems in my setup. It used / uses very low torque direct wires, lower torque than original. With my arm lateral levelness was affected by the VTA setting, which it shouldn't by concept. The block screws are adjusted for equal torque... I will have to check it sooner or later with the "feeler" gauges.

I think the main difference and advantage is regarding the non changing overhang.

Non changing VTF is a question of having the centre of gravity aligned with the vertical bearing when floating the arm. This is not an exclusive feature of the ET2 arm, there are more that are concipied this way AFAIR. Fine-tuning this precis balance is however most easy on the ET 2. The WTA Signature (which I own too) is extreme in that regard, as the vertical bearing is at the lower end of the nylon threads, where the threads vertically leave the paddle block (which swims in silicone oil). Way below the center of gravity. 

To have the statical center of gravity aligned with the vertical  (or horizontal...) bearing axis is, BTW, a solution for only half of the problem: Elongating the I-beam until "mirroring" the cartridge/arm masses and lever lengths potentially aligns also the dynamic center of gravity into the vertical bearing axis. This reduces the dynamic, horizontally pulling forces on the bearing when the arm moves up and down with warps. Ie. it reduces a source of "microdynamically varying offset" with warps - and or vertical modulation...I have not seen a discussion of this aspect anywere yet, but it's a weak point IMO of the WTA and unipivot arms. If one considers the tiny metal point contact (rather a microscopically short metal string) of a unipivot this makes one scratch ones head, because this interface is "elastic by design" which "even" a ball bearing is, on a microscopic level.There is much talk about the elasticity of air bearings - but actually the "better" or more close toleranced ones are rather stiff (plus being chatter  / variation free) compared to the situation in metal bearings, at least compared to unipivots.

Happy New Year to all!Hi Chris, this two remarks of yours are still open:

Pegasus:
Non changing VTF is a question of having the centre of gravity aligned with the vertical bearing when floating the arm. This is not an exclusive feature of the ET2 arm, there are more that are concipied this way AFAIR. 

AFAIR - as far as I remember.  

Oh wondrous flying Greek horse - 8^0 - please do tell of another design that strives for this high level .... and achieves it. If you don't post back I will assume none exist.

 
I don't know if we understood each other correctly: I was speaking about static balance around the vertical axis, which defines if tracking force is stable with changing height of arm/VTA....AFAIR: 
- Any "standard" arm, with a straight tube (as seen from the side), a concentric counterweight and a vertical bearing axis crossing the arm tube in the center of the tube is in principle (almost) correct.
- The ET2 is not different in that regard from arms like the Rega, or the Graham Robin eg. 
It is easier though to correct the ET2 precisely, with the vertical position of the counterweight.
But... who does this precisely – and how?- Most unipivots try to stabilize the bearing by placing the counterweight below the (vertical ? :-) bearing, which introduces varying tracking force with height/VTA.

Pegasus:
From the info in your posts here, I recommend you remove your VTA block, re-align with a feeler gauge. re-install, and if not level... (leaning tower)... it's something before it causing your symptoms. I would not install the bearing, armtube, end I Beam until this was resolved.

Humble horse, although a racing horse, listened to massa Chris :-)
- I checked on a "spare" ET2 (Yes I have one... :-) and dismounted the VTA block. Yes, the engineering, idea and precision are admirable.
Yes, some people torqued the VTA block much too much like the pre-owner / pre-setup man (are there any setup-woman...?). But not me...
Two "axe blocks" left/right side of the VTA adjustment axe press the axe with the VTA mounting block to the air bearing block. Both "axe blocks" should exert the same force onto the axe, most easily done by precise adjustment of the gaps for equal depth.
- This was/is correct on my arm.
- I tested if changing the VTA with the VTA lever affects lateral levelness of the arm. It still does, lateral levelness is sligthly different with height, repeatable for different settings, some positions good, some a bit less so. Not to an obvious degree, but IME to a degree that necessitates rechecking lateral levelness after resetting VTA, based on my listening experience, specially in its effect on the bass.
Sorry for the still not totally happy news :-)
This is in my system with two twisted naked 0.1 mm silver wires,  two L/R independent caple looms in a ca. 10cm diameter, very low torque on the arm apparently.

@chris:

This is for SLAW and it is also for PEGASUS  
Jcarr and the ET2 VTA

Can you please explain why these two names in big letters?
Did these two persons something wrong in your opinion?
I don't hope so.

I don't think that any sort of superior beings / majesties exist in this thread or in engineering. There is only superior design.
The VTA design of the ET2 design has it, but with certain qualifications, as seen above.
Engineering is optimizating for and starting with certain parameters. Bad engineering is forgetting important parameters. But even good engineering can only optimize for a given *choice* of parameters. One necessary choice  of the ET2 VTA arc design is that of a certain precise height for defining 0 degrees. Therefore the optimization only works ca. perfectly for the chosen parameter. As explained by Richard.
I did own already an ET one, which was followed by the ET2. And I most usually never needed any lessons about setup or tonearm geometry.
cheers...

@slaw 
but you commit the continuous crime of not using the ET 2 for now.
This is a crime onto your ears... ;-)
I did the same for a certain time.
And I admit the crime of not using my Thales Easy for the moment.
Probably because I don't understand it. As a stubborn swiss I am uncapable of understanding superior engineering and mechanical skills.

@slaw 

...
I realize that the platform it was on was the main culprit. In the meantime I decided to go other routes in which I’ve learned quite a lot from.

The freedom of will is a crime these days, which is a joke in the context of our discussion...  ;-) (But is actually not really a joke)
While the ET2 sounded very good on the Merrill Heirloom turntable, The modded Technics unleashed a new level of solidity and added transparency, which is due to the absence of sprung subchassis and rotational movements of the subchassis. This is in short what I learned.

Since this thread started I have been contacted by numerous people wanting to join this party, but they are too intimidated.

This is the reflex thought that I heard often, but IMO the ET arm is not only very transparent sonically but also in its technical design.
It’s quite easy to adjust and very logical so.
Regarding what I have seen in radial tonearm adjustments, I’d say there is *much* less probability that something is going really wrong. To do it really optimal it’s the usual old song... :-) And not different than any other analog setup.
(Typing this while listening to my Raspi3 Hifiberry Digi+ streamer...)

The challenges for an audiophile are manifold.

In the end it's only a question of the correct mounting distance of the central mounting screw. Everything else can be adjusted by rotating the base around the central mounting screw, although it might look "non straight"... ;-)
Moderate arm length adjustments can still be made on the arm itself if necessary. Eg. to place the three base spikes more in the center of the arm board, not too close to the armboard edges.
The distance is 210.96mm if you have digital drill-fingers :-)

@slaw: Regarding Mapleshade scale - as much as I like it's precision, it is always drifting slightly (besides the necessity to place the needle at exactly the same spot).Thinking about it, I dream about a solid 5kg linear low noise power supply to feed the scale and to be placed on the subchassis while measuring :-)

- Regarding I-beam and weights: I often used BluTak to adjust or increase the counterweight mass to a certain degree and never felt it was compromising the sound in any way. I also form tiny balls of ca. 0.05g (or less) to precisely adjust the VTF in a repeatable way (by putting on and taking them away). For this I measure these balls on a 0.01 precise Mapleshade scale. BluTak is simple & very practical.

- On the website of the Adanalog MG1 arm – which is similar to the ET2 – several of the user images show Lenco drives with new plinths, and I heard very good sounds from a Lenco / Reinders PTP / limestone plinth with an MG1 arm.
In my experience idler wheel or direct drives work very very good for air bearing arms, ie. optimal. (Better in my system than a very good Merrill Heirloom, a medium weight belt / subchassis ET 2 combo).
- I think this has to do with the tendency of a belted subchassis to slightly  (counter-) rotate around the platter axis at low subsonic frequencies and the way this continually decenters the air bearing a bit, compromising (to a certain degree) bass quality and others. The very low horizontal resonance of air bearing arms adds to that effect.
A radial arm has the center of its horizontal mass (almost) in the rigidly placed bearing and so the cartridge/arm combo is not displaced by horizontal accelaration (or much, much less).

@ct517 the design difference has for shure not escaped me - "interesting differences" indeed!
But in regard of horizontal mass, the degrees of freedom of the air bearing (not the details of bearing tolerance and pressure) and its placement relative to the subchassis and platter, they are very similar. That's the point. And this is relevant regarding suboptimal drive pairings.

It's no accident that VPI and many VPI users have converted their originally suspended chassis towards rigid or semi-rigid subchassis coupling, similar to many of the newer (post 2000?) turntable designs.
This design change seems to be of sonical advantage (in general) already for conventional arms – my experience ist that this is even more true with air bearing arms.Interestingly, if one considers the Trans-Fi design or the Opus 3 Cantus and simlar "short arms", they reduce this sensitivity to rotational modes of a subchassis, because the rotational force on the subchassis pulls more along the arm instead of lateral. 

Regarding Decca - indeed something special.The energy it puts into an arm through kind of a flimsy structure is challenging. This is predominantly in the vertical axis, which is much stiffer. The recommandation is probably "heavy arm" but maybe in this case mating is easier with more conventional arms. Kind of "low noise" bearing, like WTT or Schröder, or some of the better unipivots. I think the Hadcock worked well (with a bit added mass).With the ET 2, the long beam is probably quite optimal, but the horizontal resonance goes way loooww. And I had strange audible effects from that, kind of "drop outs" in the signal when the horizontal lf resonance was excited. Never saw this with MC cartridges.The fundamental quality is one of extreme agility and superb natural midrange timbre.

@bdp24, the first "HighEnd" (of the 70’s) I heard was my oldest brothers Garrard Zero tt with a Decca London (Grey?) with a top Pioneer integrated amp feeding a pair of recently refurbished Infinity 1001A. I made many cassette tapes from this setup and from my brothers LP collection with music from Portugal and it’s recently "lost" colonies.
All these kept a cracking, mesmerising immediacy over all these dozends of years, besides sometimes a certain upper range "chatter".
The dynamics of the Decca London is what is always written about. But what kind of surprised me, when I reinstalled one, (refurbished by Reto Andreoli of Blue Electric) whas that this quality was even more one of microdynamics, a kind of grainless agility - besides the impact.
Superb dynamics can often be coupled to a certain relentless quality, something that goes at the expense of a heart-touching quality. Not in the case of the Decca London.In which tonearm do or did you listen to a Decca London?

@bdp24 this feels like an opened well or a stream of audio experience opened!
Some of the landmarks I know too: My first acquisition (for my fathers audio system ;-) was a Decca International arm for a Decca, mounted on a TD 124. The self-made arm board was a bit flimsy, and there was always an amount of structure bourne vibration coupled into the cartridge. My Decca arm had a too heavy counterweight, go figure. So this was ca. the scond audio item getting modified...Then the Mayware Fomula IV as its replacement, which ended with a Grado Signature and an "encasing" in BluTak, which was amazing with my hotrodded ARC SP3A. Alternatively I had a quite good Lustre GST1 on a TD 126 (a very low noise, but very boring sounding turntable compared to a Rega 2 or my favoured Walker CJ 55).On the Walker the Formula IV was swapped finally with a Eminent Technology One, ca. 1985 (?), which i replaced with an ET 2 when it came out. The tt was swapped for ca. 4 years for a Merrill Heirloom - my first "last turntable", a very good turntable, though not optimal for the ET2.After that the second "last turntable" was a Well Tempered Signature.Which I re-replaced with an upgrade to the ET 2.5, placed on a considerably modded Technics SL1210. This is my third "last turntable", since ca. 5 years...

The description of the sonic change with the Garrard reminds me of my friends system when he changed to a Lenco. Even with a very simple plinth the very satisfying solidity and propelling musicality just popped out of the speakers. Just *a lot* more "there there"!
This was compared with same cartridge (Benz LP-S) on a WTT Signature (rare beast!) to a Funk tt with FX arm. Both are in no way slouches in regard to transparency and quickness etc.
Regarding the thinness of the Delos on the VPI: When I tweaked & optimized a Benz for a customer I was astonished at how audible changes above 0.01-0.02 gram were. Too low and one gets an exciting, but edge of the seat sound, that sounds stressed sort of. Too high and the sound gets a bit dull and slow in the bass, with a lack of open timbres.
The easy way to tweak is to set the VTF low and start with small, measured Blue-Tak balls, that are lightly stuck to the headshell. (Yes they change the sound slight by themselves - but more slightly than the weight change)
Too low or high VTF has obviously the opposite signature to VTA changes. I think that the changes with tracking force are only partially explainable with implicite VTA changes. And I feel that the effect is more pronounced than VTA changes.
If one starts to think about tweaking VTA and loading, my experience is that is crucial to really first tweak tracking force (VTF) by ear, with a precise digital tracking gauge. - And high precision & repeatability in setting the needle down on the gauge.

Regarding the Trans-Fi arm: it is somewhat different to the ET 2, but it has more in common with it than with radial arms. It has an ingenious knife edge bearing for the vertical movement, a gravity loaded, open low pressure high flow air bearing, a very short and very stiff arm / sledge connection, and medium high rigidity for twisting the sleigh around the vertical axis. It is a *functionally* very high precision bearing design, that puts less strain on production tolerances than the ET 2.
The vertical movement geometry, with a high vertical bearing and considerably lower tracing point, is similar to some older linear trackig tonearms like Revox, or the Souther / Clearaudios, but is much better / stiffer in implementation. The closest today (in vertical geometry) is the RS Labs RS-1 arm. This geometry has some well known and discussed drawbacks (FM modulation with vertical warps) - but it has one less well known (nor discussed) advantage:
Placing the vertical bearing in +/- a line that extends the cantilever upwards (+/- 20 degrees) it reduces/eliminates a dynamical vertical force generated at the cantilever bearing, which is created by varying tracing friction.
The effect is very similar to the dynamic forces that are created by the horizontal offset angle of radial arms’, which varies dynamically too, and thus constantly feeds vibration energy into the arm/cartridge resonant system. Horizontal in the latter case, vertical in the case of all arms that set the vertical axis eg. on platter level or rel. low.
The Trans-Fi has outstanding customer reactions, the bass seems one of its key qualities (not as a trade-off), similar to the RS Labs RS-1. It is probably a bargain, similar to the Adanalog arm, but in engineering terms it has almost no compromises.This said, it *is* quite a huge "machine" that works only with stiffly suspended substantial turntable drives.

The tuning of the cartridge was a job I did for a friend & small audio tuning shop. and I am distributor of Ambience Ribbon hybrid speakers.
But this is not a business in any normal sense.
I run a cultural hotel including concert program and do some live recordings.
Audio is not my business - it is my passion.Around which I have acquired some skills. The Ambience Ribbons distribution came out of my interest in the product as a customer. It is a very good product but there is not a real market in Switzerland for a small company run on a small part time job.
I do not sell any analog products like cartridges, tonearms etc.
Why do you ask?

@vpi: regarding hum:
The Delos has ca. 2.5 dB more output than the Black Beauty in low output configuration, with a quite low source / coil impedance. I suspect the vdH is more in the range of 20-30 Ohms.
I was & am amazed that this information is lacking in all sources I could find, be it van den Huls website, be it eg. Stereophiles / Sculls review! The source impedance is an absolutely essential technical information, as essential as the outpult voltage. There are two reasons:- Stray capacitance couples the static mains voltage field into the tonearms signal wiring and forms a RC voltage divider, the R provided by the source impedance - in this case the source impedance of the cartridge. Ie. a lower source impedance shorts more of the coupled mains field to ground. Shielding should shunt this voltage proportionally to the degree of shielding, and by adding a higher capacitive impedance against the external field.
- For MC transformer compatibility, source impedance is the key parameter (not voltage) - it makes or breaks compatibility.

Assuming a 3x source impedance, this increases stray hum coupling by 9.5 dB, which would result in 12dB more hum with the vdH than the Delos, based on simple and precise signal calculations.
The key issue comparing cartridges is the relationship of the voltages vs. the relationship of the source impedances. This defines in essence the relative hum levels.
Rel. low impedance / rel. high voltage are desirable. The Koetsus are quite good there, with Delos and others. Jan Allaerts and vdH (?) are more tricky in that regard.

Add to that, that the signal shield of the ET2 must be open for the "mobile" wiring loom. The Ortofon arm is almost completely shielded, except maybe 5 mm with visible wires in the horizontal bearing.
In my free external wiring of the ET2 I added a very thin wire from one of the fixing collars of the arm to the ground post. This helps, but not totally cures it.

- A bright timbre of the hum signal hints at stray field coupling (capacitive)
- A dark timbre with sometimes some nasty low harmonics hints at a ground loop, ie. magnetic coupling.

@vpi: Basically the hum level is strongly related to the efficiency of the magnetic circuit and specially the coil wire diameter.
Increasing the number of turns (because of an air coil or more windings for a higher output) basically means thinner wire.
Thinner wire helps to increase the signal, but even more increases coil resistance (ca. = impedance at audio frequencies). This leads to higher hum susceptibility with unshielded wiring.
Air bearing arms need at least 15cm of unshielded wires for the wiring loom. This increases the minimal level of hum.
With luck and good systematic grounding of arm and any conducting surfaces around the arm / platter / plinth / motor, and shielding the signal cables, grounding them independently at a single point at the preamp/step up input should eliminate any problematic level of hum.
My experience with the ET2 is that it’s unproblematic with low impedance MCs, even with unscreened cables, which I prefer.
In my actual situation with a London cartridge the source impedance of the coils forces me to implement screening – which is what I am working on this weekend...;-)

The great swiss writer and dramaturg Friedrich Dürrenmatt once said (ca.) that today (in the 20th century) there is no way to write dramas. Anything is a comedy. And the greatest comedy of all is reality.I like this sort of fun. And similar things happened to me too.
It's more fun to laugh than to cry (if possible...)

I only see one solution (or is it a soulution?): A Lyra Delos in P-mount T4P-norm.
Jonathan, are you listening?
Actually it's not a total joke. I admit that the concept of setting tracking force by standardized brutto P-mount cartridge weight-actual cartridge weight is too restrictive to design high quality cartridges.
But a standardized electrical/mechanical connection eliminates in many cases a few crimp and / or solder contacts. Besides eliminating the hassle of fiddling with cartridge clips and their solder connections, and eliminating the possibility of swapped ground or signal connections. 

I use a bottle of pressurized air, this comes from an industrial gas tank company. It’s not "free air" anymore, but it holds for a pretty long time, at least with my ca. 0.7 Bar optimized high pressure bearing. I think it’s somewhere around 2-3 l/ min.
The bottle keeps 30 liters, filled with ca. 200 Bar at the beginning.
The quality of the air must be very good... ;-) It’s from the swiss alps. Try to order it to Mexico... !
Jokes besides, I think in Mexico you might get similar industrial air, and you might ask about the humidity of the air under normal air pressure situation ("exhaled" ;-)

I recently was returned to AMC (the analogue manic clinic.)
It started with staring at the cold black turntable and dust accumulating there on. We know that seeing dust & cleaning is dangerous to many in average predominantly female persons, leading to well known manic episodes. Where at some places undefined flying objects appear, in the latter case defined objects disappear in a flying mode. Including sometimes dear and important things. (I admit havin some messie traits).
The more serious part:
I had a fight with my London pony on the ET2.5 which has its damping trough inabled, but with moderate eddy current damping provided by a small magnet (far away from the wiring).
So I still intend.ed to model the complex spring mass interactions of the ET2 & ET2.5 and I asked Bruce Thigpen (once more) for the +/- precise masses involved with the ET2 & ET2.5, and quote his given data for completeness of infos on this board:

- original aluminum wand mass: 12 grams
- CF wand mass about: 19 grams
- magnesium wand mass about: 23 grams

- Joint insert into wand is 6.5 grams

- ET-2 spindle 23.5 grams
- ET-2.5 spindle about 30.5 grams.
(spindle figures are without wire or connectors)

From measurements, roughly:

the lowest vertical effective mass is

- about 12 gram, original wand with 7 gram cartridge,
- about 12 grams CF arm wand with 7 gram cartridge
- about 14 grams for mag arm with 7 gram cartridge.

- Vertical effective mass increases about +2 grams for the 2.5 spindle.

The lowest measured horizontal effective mass is

- about 30 grams, original wand and 7 gram cartridge
- about 38 grams, CF wand and 7 gram cartridge
- about 42 grams, magnesium wand and 7 gram cartridge
- Horizontal mass increases another +7 grams for the ET-2.5 spindle.

I try to let models follow, maybe some weeks from now.
The second part in my next post:

"Do the wrong thing!"
Having trouble with my London cartridges mechanical behaviour, having tried quite long, I concluded that I simply wasn’t able to apply enough damping, the thing was "meta-stable", although there were quite a few elements of greatness.
So, what do to do? I had as an interim replacement of my MC phono stage a Lehmann Black Cube SE in use for my London, set to MM cartridges. So staring into my not (...) empty cartridge drawer, I recognized a slightly dusty beauty lurking within:
A B&O MMC1, bought from a B&O dealer, seeing it’s lonesome place in a window, this was maybe beginning of the ’90s.
So out with London, in with B&O. Well... magnesium wand, ET2.5 spindle and whatever counterweight will be: "The wrong thing".
From time to time refusing correctness is indicated by your mental health officers: Yes, the horizontal resonance is around 3Hz, the vertical considerably higher but not visible. As you may have noticed in this thread, I have my counter-orthodox opinions in case of low horizontal resonance frequencies (not in case of vertical resonance).
Theories besides: This combo works absolutely *phantastical*, it digs deep into the grooves and is highly musical as well as very uncoloured and naturally liquid. It also has deep and quick bass. It stands out of the way in communicating the music and constantly bringing this amazing slightly shuddering feeling when you enter different worlds from LP to LP, hearing amazing musical, timbral, expressive nuances.
So my quintessence is: From time to time, try things that don’t work, as far as anybody knows. And be amazed by the unexpected joys of reality vs. correct thinking. It is indicated for mental health - and for sheer pleasure & guilt.
The MMC1 is one great cartridge – as probably the MMC2 is too - and it works in whatever ET combo, I have to assume.
This is probably thanks to the B&O engineers being *the* kings of precise engineering and damping in turntables/cartridges. Remember: The actual (eternally circulated) knowledge about optimal tracing and suspension tuning / damping of turntables comes from... the B&O stable. What great lab!
PS 1: Soundsmiths SMMC1 is the ca. successor of the MMC1, except that it uses a "massive" ruby cantilever instead of a small saphire tube (with superbly mounted paratrace diamond in the original MMC1).
PS 2: It "feels" to me like every cartridge with saphire cantilever has/had a very special quality I very much like: The Sumiko Talisman S, my "special" Jan Allerts MC 1Mk2 (and MC2 Finish) cartridges, as well as the MMC1. It is a grainless coherence and ultra-quickness through the whole range through midrange into upper treble. It’s a cantilever that kind of disappears from the mechanical formula.

Hi Chris - thanks for your thoughts!
As you might remember I already owned the ET One and bought the ET2 about when it came out, and the physics behind interest me and I try to understand, master & use them since a long time... and I actually like to adjust & optimize the arm :-)

The London cartridge has a very uncommon combination of very high horizontal vs. very low vertical compliance. (ca. 40cu or more, vertical is below 10 cu). With conventional arms this leads to a one octave separation between horizontal and vertical resonance.
So, the cartridge does somehow the same "thing" with normal arms as the ET2 / ET2.5 or other tangential arm do with normal cartridges, (air bearing or mechanical passive arms) or the Moerch DP8 or the Dynavector arms: They split the resonance frequencies (of "normal" cartridges) too.
With such cartridges, I think Supexes were similar, you end up with two times the stretch of resonance frequencies - which is critical.
It results in an optimistic 12 Hz vertical resonance and 3 Hz or even lower horizontal resonance.
My London cartridge was restored and optimized by a swiss guy who learned / was trained & worked for Garrot Brothers. It has an even higher horizontal compliance than the usual Deccas (leading to lower VTF)

The lack of damping in the suspension (which provides a highly linear and probably also frequency-independent spring force) makes damping IMO a necessety. My small magnet is simply not enough, though it works very well in normal situations.

It sounded very good in pressings that worked. 
I use.d the new long i-beam, single spring, lowest counterweight far out (to bring this stiff vertical compliance to a rel. higher vertical mass).
And no it was not the low resonance of the i-beam / counterweight that made the thing slightly instable. And neither do I see a real indication that the low resonance frequency in itself was the problem:
The MMC1 has a similarly low horizontal resonance (ca. 3Hz) on my ET2.5 combo.
My feeling is also that other cartridges work more linear with wide excursions: They are more bullet proof, and "behave" better or / and are implicitely more damped.

It is BTW principally by no way easy to tune a tt suspension to fit / isolate a highly untamed vertical resonance of not far above or around 10 Hz from floorbourne vibrations.

Hi Chris - yes I remember that frogman has direct experience with a Decca London, although not all Londons are created equal, you could try it. Although it also waits for being mounted in a Thales Easy arm... sending a cartridge between continents needs a bit of research how to do that in an economical way.

I think fluid damping is necessary with the Decca on the ET2 or 2.5.
Taking Bruces numbers, I doubt that "my" "heavy" setup will essentially change resonance characteristic compared to the lightest setup (in numbers: ca. 49g eff. mass with cartridge vs. 37g). It’s a not really considerable 30% difference, which results in ca. 15% difference in resonance frequency. Eliminating a major problem normally means considerable changes.
Ie. a 15% resonance frequency change is IMO usually less important than to introduce damping.
As the London Deccas come with a very "clean" spring with practically inexistant damping - which leads to some of its qualities, overdamping with it's sonic issues goes one or a few mile with that cartridge...
The Grado wiggle vs. London dance is a bit like senior gymnastics vs. voodoo dance.

Hi Davey, you’re outside of the fenced green pastures of audiophile correctness if you mount an ET2 or ET2.5 onto a Linn. But outside the fence, there’s life too!
Because the ET2 / 2.5 is not a heavy arm it’s feasible, probably needs "expert tuning" of the springs.
Caveats are two: The leverage of the arm tends to tilt the subchassis slightly from one side to the other when playing an LP from beginning to end.
And there’s a second issue that can be resolved with a Linn accessory / modification: The Bespoke spokes, that stop the subchassis from rotational modes, but leave the subchassis vertically decoupling.
This is crucial because rotational modes are only very mildly coupled to a radial tonearm (they counterhold the vast majority of these forces within the horizontal bearing, except for slight dynamic imbalances (in the horizontal plane).
With tangential arms thr inertia of arm and counterweight don’t compensate external forces. So rotational modes lead to slight, but constantly varying horizontal movements of the bearing and cartridge suspension, and therefore a subjective instability, in effect like a wobbly skating force. These modes are "tracked" because usually the horizontal resonance of the arm is below (or around, and not better,) the frequency of these rotational modes.
The Bespoke modification has some slight drawbacks, it seems, but it is in effect quite brillant and will work wonders in this (specific ET) situation.

- Regarding London Maroon / Art Dudley (Listening 156):
In the comments about arm matching, Art got the resonance frequencies of the Abis SA1 the wrong way: The horizontal is in his test about an octave lower (centered around 6Hz) vs. vertical (around 12 Hz), not the opposite way round.
Assuming the SA 1.2 has only slightly differing vertical and horizontal masses, this leads to a 4x stiffer vertical compliance than horizontal, this is what I wrote, and was to be expected.- I don't agree, that a horizontal resonance at 6Hz poses any problem, but optimally the vertical resonance is considerably higher, which is the case with the SA1. Therefore (and because of the chunk solid construction of the arm) it is expected that the SA1 was (slightly) preferred. But damping would be desirable as also his situation shows.
- In one of the better german magazines there was a test of the London Studio which is similar to the Maroon, but using a front and back tie-back thread, instead of only one pulling back. The review  sounded somehow surprised by the (even better than expected) sound quality, which Intrigued me. - Is this possibly the best sounding London, at least of the "basic" ones?
- Reflecting abouth this review, a suspicion came up: The double tie-back thread is probably for DJ cueing reasons, but... it stabilizes ("grounds" ?) the cantilever better, and must reduce horizontal compliance. Both are very desirable effects - specially in the ET2 arm, because it might lift the horizontal resonance a few Hertz, a few dozen percent. This gives more playground for optimizing the counterweight / spring combos. If buying new - this would be my choice (and using it with the damping trough).
- If one can go without the airy-fairy upper highs of the more modern styli, the conical stylus has its own considerable advantages - musical coherence: See DL-103 & Ortofon SPU.
(OK, I think the VTF is a bit higher too).

Thanks Chris - pretty sums it up.
- Why London?
I recorded my brothers "world music" LP collection from the 70’s end of 70s to ca. 1980. Garrard SB 100 Decca Grey cartridge, top "high end" Pioneer receiver :-), recorded to a portable JVC pro cassette recorder.
After 40 years, these recordings still have this abundant energy, are fun to listen (and in some high level upper range passages sound a bit "relentless", diplomatically speaking.)
But: Unforgettable.
- safe bet for problems: High quality low friction arm with high lateral mass, as I experienced.
- *thinkable* solutions: Such arms with damping (a bit vertical, more of it horizontal) - I’d try London in an ET2 with a good amount of damping.
- Or, known working solutions: Unipivots, like Aro etc. with a moderate amount of damping, and the Well Tempered arms.

Ahh, good to know that! :-)

Hi Chris it looks not the "traditional London way" as in your photograph, instead it's this way:
https://audio-intl.com/wp-content/uploads/2018/04/c_91_pro.png
If one looks carefully, one can see the thread that "secures" the cantilever from the front against backward scratched groove motion, instead of pulling only from the backside.

- BTW - anybody had the issue, that the damping trough "moved" over a long time? Ie. the bonding tape letting loose slightly, not symmetrically bearing side vs. outer side.
In consequence the "oil bath" is not level with a level arm.

- Any plusminus systematic listening impressions with the long i-beam? Ie. whether the counterweight far out (lower i-beam resonance) is preferred to less far out and a heavier counterweight?
I tend to feel ( ;-) that the bass with my high compliance cartridge / ET 2.5 is unusually quick and extended with the long i-beam, and with the counterweight rather far out.

The road: started for me with the Et One ca. 1985. After I’d explained the physical drawbacks of the construction a few months earlier to an enthusiasmized friend... :-)
It worked sonically rather well - with the one exception of the somewhat lacklustre sound of a Decca London cartridge, which I couldn’t explain - at that time.
Then, ca. 1987 an offer I couldn’t resist: The offer for an ET2.Later adding the damping trough, in between the (shitty) WISA pump and the expensive & OK lab tank, which now is broken thanks to ageing PVC. It is replaced now by an adapted cheap PE gasoline tank. Then the high pressure bearing and the ET2.5...The evolving ET 2/2.5 is the best audio & musical joy investment I ever made. Returning to it after ca. 15 years of Well Tempered Signature front end was like coming home.

The one thing I always come back with surprising consistency: Maximized (and almost) perfect lateral balance is surprisingly audible. The ET2 / 2.5 is an audio measuring tool for forces on the cartridges cantilever. It’s more easily adjustable than any other arm IMO. First level the turntable on its own as precisely as feasible (more difficult because without the help of the ET2.) Then level the arm on the ’table by nulling the tendency to glide away.After this, in my somewhat "organic setup" (wood floor, wood parts in the base), I level the integral turntable with help of the arm.

And the other thing really standing out: The front end is so revealing that several times during the last weeks I heard something slightly off, and it was either the floor "working" (level, see point above) or:
By handling of the arm, touching the counterweight or some other handling, the VTF differed *slightly* - ie. not more than 0.015 gram. It was eally less than 2cg. Context: I do not really tighten any screw in my setup, because of (...). This *was* audible in a close to blind test situation - "... somethings sounding not quite... ??". In such a revealing setup it’s *musically* rewarding to a surprising degree how much (less than) 0.01 gram VTF can do, sonically.
I invite anyone to try first before argueing against - an ET2 or any other superb front end BTW will show it. (And yes, I know that temperature and other factors modify the dampers properties constantly).

@chris
I think the reason for the ET2 spindle design was
a) it was quite brillant with any cartridge (and still is).
b) the ET2 spindle is ca. 23 g vs. 31g (ET 2.5). This concerns horizontal mass 1:1.
Also the bearings outer tube is considerably heavier. This concerns compatibilty with sprung subchassis.

Mid 80's there were a lot of english (and swiss/german) tables around, with rel. lighweight sprung subchassis. Minimizing mass was important for compatibility.And keeping the spindle (and horizontal) mass low was important for optimized MM & MC compatibility. (If only not to stand too much out in the theoretical rain concerning "much too high horizontal mass").

The high pressure bearing increased stiffness of the bearing, and the larger spindle increases stiffness of the bearing by an additional factor of 2.5! The ET2 bearing is stiff to begin with (it's not the "intuitive" air cushion one imagines), but the  ET2.5s large surface high pressure bearing is even stiffer by (guessed) almost an order of magnitude.
Practice shows that even the high compliance B&O MMC1 "likes" the heaviest ET2.5 configuration, without getting hickups.(as it "likes" a longhorn stabilizer even though the coupling of the  cantilever to the body is of rel. low stiffness.)

Best wishes - & hopefully less long states of mental hibernation or coronation...
I wanted to bring to your attention this jewel of a technical discussion from Pierre Lurné:
https://www.tnt-audio.com/sorgenti/lurne_air_bearing_e.html
now, well... :-)
- even a french emperor walking the naked truth may be clothed by invisible (very, very) small pieces of textiles covering some sensible parts of the body (impeding some directions of clear vision).
Even if he's called Prince Pierre Lurné who built one or two of the most beautifullly and perfectely crafted one point tonearms. (Which sound excellent too.)
- split horizontal and vertical resonances are rather an advantage than a drawback. (I've not seen or read ever convincing proof of the opposite, and Moerch is following this path with his top arm).
- therefore some of the cartridges with remarkably good bass do feature distinctively different compliances in both planes leading to the same split resonances with conventional tonearms. (eg. Decca, all true mono cartridges like Myajima).
- Listening, measuring and comparing the vibrations on the headshell of the ET2 vs. the vibrations on the outer bearing housing with a measuring coupler showed a remarkably similar frequency response at least up into the upper midrange.
Ie. the air bearing seems to be pretty stiff & well coupling to audible frequencies. The ultrasonic spectrum hitting conventional roller bearings, seems to me rather a multitude of metal to metal resonances of scattered and reflected energy back into the arm modulated by slightly elastic and moving point contacts. Ie. a process prone to  a certain alu-foil on comb quality, a form of distortion.
So I think the air bearing grounds vibrations rather well - and without introducing variable noises (except those inherent to the air film itself, which are like a very low level stable white noise).

Hi all & Dj...
Just my thoughts: Your selection of cartridges is tasteful, even mouthwatering...
Generally there is only one sort of cartridges I'd rather stay away except for a wish to abuse time, like to teaching a rhinoceros to dance. This is the combination of high horizontal compliance with low damping. This means Deccas, maybe the DJ Decca (double tie-back string) mightwork - this would be highly interesting. (It's worth the hassle, but...)
Myhigh compliance B&O MMC1 (root of the Soundsmiths) works *superbly* even if it shouldn't. This is because it's  "well behaved" = damped.
The new ATs are higly interesting - I'd look maybe more for the 500 series and a Shibata tip. I read a careful review in a german journal where they hinted at a slightly more upbeat character of these vs. the more refined (aka. slightly over-civilized) 700 series. (There are technical reasons for that). They play in the league of the Ortofon Black.
The Nagaoka I don't know, the Grado might be less damped (mechanically) and a bit more characterful=" musical !!!".
The Denon and Hana seem to be winners. Specially the Denon but maybe the Hana too will profit from a 5g brass "shim" between headshell and cartridge. This worked wonders with a DL 103 in a friends Thales Simplicity arm. There are IMO no reasons to expect different on the ET2.
The lower compliance of these two MCs will make setup somehow easier specially on a springed subchassis turntable.

BTW - constant VTF isnt’t the issue of the arc-block for VTA adjustment. It is the constant (zero) overhang with different VTAs.
Increasing VTA by increasing the height of the pillar of a radial arm, the arm shortens in the horizontal plane. Thus overhang is reduced:... by 0.5 mm for a 9" arm with a change in VTA of 3.8 degrees... which IMO is close to academical... :-)
The VTF varies with height if the counterweight is "underhung" or "overhung". Ie. if the centers of gravity of arm tube / cartridge and the counterweight "connect" below or above the horizontal bearing. This is the case with most univipots and strongly with the Well Tempered arms.
What is special with the ET2 is that one can perfectly balance this (if one wants to and knows what to do :-).

Hi Nandric, one of my fondest memories is a FR 7 /FR 64 combo, the sound and solidity of which I see like carved out of rock. I also remember how low the horizontal resonant frequency was... fumbling around with tuning aspects of a tonearm is not to everyones taste. Neither is studying physical formulas - and even more difficult is to accept that some things work although they shouldn’t.
I exchanged posts and mails with Richard Krebs earlier on and I didn’t find his observations absurd in any way, rather I see them as a worthwile contribution to the knowledge base here, based on systematic experiments.
They (partly) fly in the face of mainstream analogue wisdom. Which BTW has been challenged more recently by the Moerch DP-8 which instead of staying proudly slim on horizontal mass, states big is beautiful (on the horizontal level...).
Rigidity with low resonance structure and high mass is helpful in more than one aspect, sometimes. The ET2 / ET2.5 is a triumph in making an air bearing linear tracker "compatible" with sprung subchassis tts. This triumph was made possible by rel. rigid low mass parts and by increasing the complexity of the horizontal mass combo by decoupling the counterweight. This is in many situations desirable (because tunable), is prerequisite for sprung tts, but it is not necessary for low compliance cartridges - in fact (what Richard is saying) eliminating the additional decoupling can in some cases improve the sound.
"His" arm looks like many highly regarded (also) superbly (but differently) engineered air bearing arms, but is based on the ET bearing. Although not for anyone, I like the inquiring spirit and the idea - even if it appears like heresy to moe. :-)
Let’s not forget, that the resonance frequency is changed less than 30% by adding 30g to a high hor. mass tonearm like the ET 2.5. Which, with most records. causes no problem. Increasing hor. mass with a linear tracker just increases the necessity of really good hor. balance adjustment and levelness of the platter.
Even if the adjustment procedure might look like a religious ritual... ;-) it’s very much worth it!
 

@nandric 
From what I have read and understood, the removal of the post has only to do with eliminating the bot-trigger word "me.t..." to save the discussion thread being flooded with spam. Using this abbreviation is "logical" and understandable in verbal communication but it triggers the spam button on web-based discussion platforms.
Removal of that post had IMO nothing to do with something personal against you.

 

@ct0517 & @lewm 
Using the same counterweight spring, to half the lever, ie. the distance of the counterweight from the pivot axis and to double the weight increases the resonance frequency of the counterweight-spring system (by SQR(2) methinks).
Ie. bass pulse / group delay aspects come into play too. With the decoupling the resonance system is more complex than without (nifty 4th order instead of 2nd order).
Increasing the weight of the assembly / counterweight increases the "weight stress" *and* the "leverage stress" on the air bearing. Optimally, in mid travel of the arm, the center of gravity of the whole arm should be centered in middle of the air bearing. (Something eg. the Kuzma, Air Tangent and adanalog arms are by design). A short i-beam / short lever severely shifts the center of gravity toward the end of the bearing and increases the leverage stress. Ie. the bearing works less stable.

Is there anybody reading here, who is experienced in modeling mechanical systems as equivalent electronical circuits?

I was not able yet to figure out the equiv. circuit for the (horizontal) 4th order system tonearm / decoupled counter weight myself. I think this could be very helpful in understanding and optimizing the setup.

The longer i-beam allows much lower resonance frequencies ie. potentially a wider tuning range.
Intuitively, tuning the counterweight res. +\- precisely to the spindle/arm/cartridge resonance and optimizing the damping should „drain“ the main resonant energy, as shown in certain plots of the decoupled Dual counterweights in the 70s.
I‘d like to see and play with these interactions in a quicker, less time-consuming medium than the actual tt setup (with measurements another PITA).

I was able to optimize the mechanical panel resonance of aMaggie MG 3 and MG 3.3 in a similar way, but kind of a hybrid mechanical/electrical filter. It worked :-)

@nandric
your posts and experiences with audio are still appreciated. The removal of the post has nothing to do with paranoia, neither western or communist. It‘s only about keeping the spam cleaning task if the moderator low, by removing trigger words for bots.

 

"Normally" the I-beam is in line with the tonearm, ie. "horizontal" tonearm & I-beam.
(I think that's what you see in the manual.)
"Underhung" - which is popular and necessary to a degree with unipivot bearings, the I-beam would slightly slope down to the end. But... this is neither necessary for the ET2 nor does it make sense dynamically.
If not going "normal" I'd try to slightly lift the end of the I-beam, meaning to set the counterweight sligthly above horizontal.
Dynamically it is IMO optimal to have the line from center of mass of the tonearm & cartridge to center of mass of the I-beam passing exactly through the center of the bearing tube.
The beautiful thing about the ET 2 bearing is: It works admirably well even without thinking too much about such issues :-)
 

Coming home from a show and maybe listening with ones partner is always interesting and sometimes also telling something, but what?
I was favourably impressed even by my "little digital wonder" of battery-fed RPI3-Hifiberry Digi Pro streamer / CEC TL2 CD transport, battery-fed MF DAC-V90 digital front end. Everything you could wish for was impressively there...

And then... my wife called for Grieg Peer Gynt by HvK which I was able to stream - I quite like this recording on CD and it sounded good streamed (Roon / Qobuz) but my wife reacted somewhat lukewarm, after some highly impressing audio experiences just before - and she wished for phono.
I have my alternating phono & digital sabbaticals. Saturday ended such a more than half-year sabbatical on phono. The return of... the king? ...the glory was shocking, I simply wasn't prepared for it. The connection to room, music-making, dynamics and see-through transparency and coherence hit me right between the eyes. (And later all the miserable pressings, noise & wet-play artefacts of several records). The stability, dynamics warm, full & extremely resolving sound with a stand-out lucid quality in the bass has floored me in this unattended moment.

- Within the time gap rel. to my last phono phase I changed only two things regarding phono: I started aurally from new, with a digitally cleaned set ears. Last time I only had a short time with the I-beam. And, under my speakers, I replaced harder one-point (center of gravity) springed feet with an adjustable air cushion. Already before this did cut the feedback loop within frequency range which my speakers are able to reproduce (realistically not much anymore below 15Hz).
I think both aspects contributed, but (I guess) at least half of the improvement in see-through bass transparency and general palpability comes from the I-beam.
Ie. the I-beam is IMO a must have for any ET2 / ET2.5 owner.
Reducing feed-through from speaker to floor, and floor to turntable is (as we all know) very important.
The improvement wasn't subtle at all!
The other involved gear in my system is:
B&O MMC1, ET 2.5 (Audio Consulting silver tonearm wiring, pressured air bottle) / Audio Consulting  battery phono / Audio Consulting TVC line amp / Berning ZH270 with some mods / lessloss speaker cables / Ambience Audio Ribbon Hybrid Reference 1600 / Ambience subwoofer / and TakeT supertweeters and TakeT wide-range "energy-fill driver" WHDpure.

- Last week a post-Munich dealer / customer exhibit took place at Micha Hubers (manu-) factory near Zurich. I met Micha for the first time, haven’t used his products in my own system (yet).
On show were two Thales turntables and a new smaller EMT ’table, mated with Exquisite low and medium output & new EMT cartridges on a Thales Statement & new EMT arms. Electronics were a prototype Thales (phono)-preamp, EMT tube phono listened through CH precision amp & Stenheim 3. And an Audio Consulting (of Geneva) chain, consisting of Tube battery phono / amp & Rubanoid hybrid speakers w. lessloss speaker cables. The factory tour was totally impressive, both from a technical "artistic" level, the research behind, the agility, commitment and efficiency of the team - and Michas relentless fine-mechanical searching spirit and his modesty & friendlyness. Every audio afficionado will be totally impressed by the precision & handcraft applied by that team in a highly inspiring atmosphere.

Listening to "show systems" has its limits, less here than, it seems, in Munich. A moderate area, old wooden floor room made some floor / room resonances, apart of which the huge qualities of the front end & systems were very audible: The breath, resolution, dimensionality of the A.C. system, the precise matter-of-fact see-through quality of the CH Precision / Stenheim system. The extreme levels of precision, focus, natural ebb & flow of the Exquisite-powered front ends was supremely audible: The Statement arm is flabbergastingly open & transparent, it’s in every technical and audio detail a tour de force, the engineering and "simple form complexity" of the parts, the execution and its seemingly simple function. As a scepticist regarding complexity I am still in awe of the total success of this very complex concept. It sounds totally lucid and non mechanical, like an exquisite master tape. The Exquisite cartridges whose interiors and fine adjustments we could observe "live" under the lab microscope are unique in more than one way, which made itself very (in-)audible in a complete lack of artefacts. They are indeed state of the art as well. No wonder some big names use OEM cartridges out of Michas manufacture.

- The massive reduction of overhang in the Thales tonearms and hence the minimizing of skating forces does to my ears very audibly increase tracing stability under dynamic signals, something we experience too with a correctly adjusted air-bearing arm. The advantage of "Tangential" is IMO primary the reduction or elimination of overhang, not the moderate or small angle error of radial arms.

If it must be simple in handling and more conventional in looks & adjustment than an ET 2/2.5 (and if finances are available), there is IMO most probably no real alternative for the Thales arms, notably the Statement arm. Specially impressive ist the smooth solidity of all bearings and fittings - and their finish: Pieces of art without snobbery. And the sonic result is simply superb.