Eminent Technology ET-2 Tonearm Owners

all the leafs are brown... the fall is coming.. :-)
Yes Blue-Tak is something to have around, and I use it (I'm swiss :-) on my jewelers screw driver - when I remember...

No, I wasn't in LP mastering / cutting, but I have a profound interest on the electronic & physics side of that hobby. I make recordings of concerts at our place, and did some recordings already in the 70's with a semi-pro JVC portable cassette-deck from my brother.
And I did a few Magnepan modifications for customers, and made new low-diffraction panels, and calculated all new crossovers for MG3 and MG 3.3s.

I had to trade in the ET1 for the ET2, so I don't own it anymore, contrary to the ET 2 it was slightly crude in set-up and detail solutions - but it worked very well.

My main messages about the arm (which I always loved) are as follows:
- If the bass is off, it's probably the set-up (side level or maybe a too softly springed counterweight stud).
- If I only touch the VTA adjustment a bit on *my* ET2 - the side-leveling is severely off. If it's not, I was lucky. To check is better than to believe...
- The "critical theory" against air bearing arms, and specially the ET2, stands IMO on very shaky feet, as I tried to show above. If there is a structural problem it might be the slight elasticity in some of the joints.
- subchassis turntables have two main problems with an air bearing arm:
- the lever mechanism of the shifting mass offsets the subchassis (-> increases sideforces)
- The needle drag problem, ie. the varying friction with tracking, potentially sets up rotational forces in the subchassis, with every arm. This leads to a slight instability in the subchassis and pitch uncertainties. But it also kicks air bearing arms in a different, very undesirable and quite audible way: Side-ways. (Much more audible than a radial tonearm, where the kick goes much more along the stable axis needle to arm bearing).
So one gets both problems - the bass instability and the pitch instability.
But it's still feasible and it can sound very good.
- In my book of experiences, every screw that creates a touch more grip than needed to keep a joint or a connection from gliding, introduces quite severe grades of transistor-feedback sound. I understand this as a necessary minimal torque, but every further bit of torque is like tuning the screw up, in the sense of a steel string. Tune these down & out, and they ceae to resonate. It is less storage of resonant energy. So my ET 2.5 runs with minimal torque on all screw connections. It sounds less artificial and more integrated to my ears.

My ET 2.5 sits now on a partially spring suspended Technics SL1210 with some modification on the electronics. With a very old, original AT OC7, which sounds very, very good here. I know, it shouldn't :-)

Hi Ct & Frogman!
"My place" is a historical house we run as a hostel, with a cultural program (which I organize with a few friends). The remaining time (not much) & energy (still enough) is spent on hifi and developing concepts & ideas. This has a company name and is actually more like a small personal counseling service to customers (who often are or became friends).
And I play in an amateur wind-instrument band.

And yes, Frogman, I read about and appreciated your similar experience with the screw torque. (And the sax (?) playing).

You're right with the several modes to mis-tune an ET2. It needs a bit of 3D operational understanding and then every screw (inside the brain too) falls into its place.
I leave the basic side-ways adjustment (the two posts) with very low torque, and keep the locking tilt screw fixed. I do lateral (and vertical) fine-tuning with the tripod screws in a balanced way: up one, down the other. The torque on the central pillar fixing screw stays the same this way.
I think it is really moving the VTA lever itself which dis-balances the arm a bit and the mechanism is not quite keeping the arm quite level. I pull the VTA lever with one finger using the bearing as a base, so there are (almost) no forces going to the plinth and the connection to it.
I "feel" the same about less interfaces is more (underneath the Tiptoes). But I got good results with small single steel pieces underneath the tiptoes. I think a whole steel or alu plate is less desirable. I will look to improve on this in my actual ad-hoc installation, which has a few things to improve.
BTW another tweak I use is trapezoid wedges of cardboard which I slide in (vertical) underneath both ends of the bearing housing (or damping trough) until they slightly lock the bearing to the plinth. This absorbs any horizontal elastic movement of the bearing on top of the pillar. They have to be applied with plyers, and should put symmetrical force to not unbalance the arm. I do this after having found my preferred settings (... :-)

Yes, this makes sense, and in an additional view-angle it's also like looking at ground loops like HF currents, overlaying each other with more or less phase differences, because "tuning" the screws (down) also tunes (down) the speed of each transmission path individually, and tunes (down) the Q of the resonances individually.
This BTW is also an aspect in different ways of mechanical equipment grounding. Depending on how you ground vibrations, more or less energy travels at more or less speed across the room, ie. across the floor, eg. to ones "ground receptors", the feet.
I mainly think in terms of rigidity as: "how much is *really* necessary". This & not more. One really has to check by ear, with a "natural" and integral way of listening. The "low rigidity way" keeps the musical range much more together, sounds more fluent. But it may sound less "impressive", less bassy, less "brillant" etc. Instead one hears more of the structure of sound, and listens into the quality of instruments *and playing* quite a lot easier.

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.

Yes frogman & CT0517 on a John Deere, what nice illustration of Americana seen the other way :-) It shurely tunes bass sensitivity, although only in a limited interval range...
Regarding "spit", isn't what most lay people (ie. the non-blowing family members too) think it is. It's mainly distilled vapour from the lungs, with maybe a bit of sulfur molecules here and nitrogen mol. there. But not much spit, I think. At least not anymore after one played two or three years.
I call my baritone sax my personal distillery. But the bowed neck (?) of a bass clarinet works already nicely as such.
Regarding trombone: This is a really great instrument! (And - ha! Ray Anderson will play november 11 in our concert program! :-) The instrument is extremely powerful in a seductive way, a lot of colours and expressive. Must be fun to play with this huge tool-box.
It's funny you mention this aspect, of first getting the fundament right, the rest then falling in place: If I'm asked about what defines the quality of a well set up ET2 (or even more a ET2.5) it is the "full-range" sound from the *lows* up, surrounded by a lot of air in the bass (first): Bass ambience. Yes, it's also sublime upper ranges, but it starts with a lucid, airy bass range with a high resolution of bass timbre & pitch.
It sounds "correct" by itself while not sounding tight-assed NFB correct.

@flemke: I agree! These are gradually more consequent and less reversible ways of what my cardboard wedges underneath the manifold/bearing do.
The wood option might create a more stiff but more vibration conducting, but less absorbing pathway than cardboard.
I might try a hardwood wedge someday. I like tweaks to be as reversible, low mass and "elegant" (not necessary in the visual aspect ;-) as possible.

Hi Dover, thanks for your clarifying comments!
Regarding the pressure compensation, it might help to use the analogy of a stiff power supply (air supply & reserve connected to manifold) with a few local supplies (local pressure zones around air capillary openings to the bearing) coupled with high series resistance (capillaries). As current (air flow) drops on one of the sub-supplies, the voltage (air pressure) rises - kind of a passive feedback!
Regarding the usually alluded inherent "stiffness" of mechanical bearings including unipivots, it's worth to consider the following thought:
No material is stiff, everything is more or less elastic. (With some unique properties subsummized in the poetic word "character", importantly damping, and including speed of transmission). Reduce pressure area, and elasticity increases. This affects resonance frequency inherent in any elasticity / mass combo. *Point* coupling as in a unipivot or a spike point, looked at on an "atomic level", is in no way making the coupling stiff, it's the opposite. The surfaces meet in kind of a balanced force & elasticity state, a bit like a jelly ball swimming in water, to put it to the extreme. You don't get steel more elastic than with a perfectly pointed unipivot interface. Then think "it" as an elongated point and you see something like a short subminiature "string" at the end of the point - quite elastic, like a very small piece of microscopic harpsichord string. "Flatter" points like balls have much less of this, and make stiffer bearings - that depend more on extremely complex polishing processes. Some arms use the tip of a roller pen, quite clever!
The whole "argument" (rather a mythical marketing image?) of the "mechanical diode" is moot. Point coupling shurely does "something" (as everything we do does) but shurely it is not "stiff coupling" or magic diode processes. It might eliminate eg. multi-point rattling by a multitude of low pressure indefinite points, eliminating noises of "buzzing paper on a comb"-effects, tingling in metal-to-metal sonority.
And... air bearings are at the total other end of the scale!
That's what Bruce tells us since a long time.

A question to all:
Does anyone have tried grounding the air supply's static charge?
I think Richard mentioned that he connected the brass of the pressure gauge to ground (which ground, where?).
Has anybody else tried it?
There are - expensive - antistatic "hoses" available. Would be interesting to try, maybe even only on the short distance between the last air tank (preferably antistatic & grounded too) and the arm.
Other grounding ideas? Like putting a copper grid into the air tank and potting the grounding wire in hot glue?
BTW my simple air tank is a 20 gallon fuel "canister" (unused :-) with a long and a short aquarium tube entering the cover of the tank reaching the top and the bottom), the whole sealed by hot glue and padded with acrylic wool. Very simple , cheap and working well.

Interesting “facts discussion” about linear vs. radial tonearms, most have probably read it:
http://forum.audiogon.com/cgi-bin/fr.pl?eanlg&1266367593&openfrom&1&4&&st100
Sadly mostly boring (ie. repeated, but skewed arguments)… but some interesting points. A main point is the quotation of a High Performance Audio Review test in the 80's measuring much higher actual sideforces and deflection of the cantilever on a SAEC radial tonearm vs. an air bearing arm.
The reaction of the (radial) “experts”: Hilarious, ridiculous! The facts don't follow their invented orthodox belief, so the facts must be wrong! The reaction of other more pragmatic non scientifical audiophiles: This is only one situation, we must collect other… (measurements).
Experimental science means, one well set up experiment with a non expected measured outcome can expose any pre-existing contrary hypothesis as wrong. In this case the “excessive side-forces”. But what am I as a humble pragmatic thinker compared to the pope(s)?
Over most of the thread the effect of mass and bearing friction on a cantilever are confounded, and bearing stick vs. bearing friction isn't even mentioned. Neither are there attempts to define the magnitude of differences of (horizontal) friction of radial vs. air bearing arms. I think/suspect that even with the “lever advantage” the best radial arm may just quite cope with an air bearing. Horizontally that is. The rest is wrong thinking about the optimal horizontal mass aka. the desired horizontal resonance frequency – for best bass reproduction with lowest phase shift. The dynamic side forces on a cantilever are simply a result of friction (mostly non existant in an air bearing) and mass. Ie. they correlate with the horizontal resonance frequency – and are taking part in a compromise, where the sonic optimum lays much lower than audiophile orthodoxy.

Frogman: If I'd live in NY or the states I'd shurely ask you for lessons on my clarinet(s). It would be fun tweaking my fingers tangentially to the holes with your help and having them (the holes) optimized by tweaking the diameters... :-).

Dover: I found your posts very interesting and I like what I'm hearing with magnetic damping - in my setup, with a small neodym magnet close to the bearing tube placed at the "backside" of the bearing, direct wiring some cms away from the bearing tube. Not tried yet the "naked" alu arm tube yet.

Setup: IMO my original ET wiring was introducing too high lateral forces. I use twisted thin Audio Consulting silver wires outside of the arm, fixed via two or three small double sided foam ahesive pads. The wires go in a light curve, with a vertical radius, L/R some cms separated, to 7cm behind the arm tube, in the middle of the travel path.
With this, the arm is a *very* precise leveling tool. It shows the slight change of levelness introduced by the level forces of the tonearm on my battery-modded SL1210 with "trick-subchassis". So I have to look for a very slow movement toward the outside at the beginning and the end, but perfect level in the mid of the LP, or mid arm travel.
Every time I heard slightly tubby bass, it was caused by an involontary change in lateral balance. Unbalanced side forces affects bass - one already has it built in with too stiff wiring.
I'll try Dovers idea of a slight overhang, this is such a delicate tweak, that it will create much smaller forces than any wrong balance setup.

Decoupled counterweight & ET: I think it is a brilliant idea to reduce the effective lateral mass - in case of rather high compliance cartridges. It makes the ET2 much more widely compatible, than the ET one was (I owned it), or most other air bearing arms, specially those with stationary outer bearing, long bearing tubes and counterweight at the opposite end.
My axe to grind is that optimizing towards a higher lateral resonance frequency than say 4-5 Hz (at least) is simply neither necessary nor improving sound. Based on the same thoughts that stand behind the Moerch DP-8 arm.
Ie. with moderate to low compliance cartridges the counterweight decoupling introduces a new (sonic) compromise instead of solving a problem. But to really hear the advantage of a rigid counterweight, one has to do a bit more fiddling with the ET2 counterweight fixing than just using BluTak to bypass the spring (which I usually did).
For high compliance - I assume - it's ingenious.
BTW I use a pressurized air bottle (rental system in Switzerland) as air supply at the moment.

Addendum: The VTA adjustment mechanism of my ET2 introduces slight (but IMO much too much) lateral imbalances when changing VTA. I assume Ct0517 will tell me that my VTA mechanism has a problem - but it was never overtightened or any thing like that, it has equal spacing around and moderate to low "clamp".
- so, after changing VTA I would *always* adjust lateral balance... :-(
- I use very small vertical cardboard wedges between arm housing and plinth to *slightly* couple the bearing to the plinth. One "outside", one on the counterweight end, underneath the damping trough. This improves stability and focus and is audible (and reversible).

- BTW I measured/listened to the energy put into the arm, arm base and plinth while playing an LP, by using a structural feedback microphone. I heard a wide-band replica of the LP signals across the whole arm structure into and including the plinth. With no audible HF roll-off "after" the bearing, it just went lower in level across the plinth, a bit absorbed probably by inertia. So much for "air bearings are inherently less stiff than radial arm bearings".
- And I heard bearing noise... like white noise, created by air turbulence of the exiting air. This has tobe put in the backside of our heads when increasing pressure on the bearing, although it's relatively constant.

Hi Chris (?) the compressed air bottle is a 200 atmospheres 60 liter steel tank. It provides "air DC" (to my arm & head) :-)

Wires: the Audio Consulting wires are twisted single strand 0.15mm silver wires with thin isolation. I dress them carefully (two L/R separated looms in a circle of almost 245 degree with ca. > 15cm diameter) going up from the arm in 90 degree to ca. 4cm above & behind the arm, slowly turning > 200 degree and back to vertically down. I measured the forces applied by the elasticity and weight of a single winding, it's around 0.05 gm. This is audible - if one does not correct for it. But I tune the downforce by ear anyway. The forces are low, and less in the horizontal plane. The end effect is what the arm does: It still skates off very slowly outside the middle 5cm to the inner and outer grooves.
The wiring works actually very well (far better than the original wiring), and I prefer to keep the wires twisted for hum compensation. Some time I used 0.07mm single strand copper wires, the applied slightly less force but sounded IMO worse.

Did you really check for absolute levelness after changing the VTA position, finding *no* change in side balance?
The imprecision is shurely on a very low absolute level, but not low enough in my case. I found out the hard way, by ear that there was a problem.

Hi Chris, BTW the pressurized air bottle is true. :-)
I forgot to answer an earlier question of yours: I prefer to use less counterweights farther out on the I-beam. I prefer it because this way the center of gravity of the arm is more centered along the bearing, and because I have less lever forces on my semi-springed subchassis. It helps to float the arm better across it's way.
It also reduces the maximum lateral mass, effective at "DC", below the resonance frequencies of arm/bearing and I-beam/counterweight.
Less counterweights farther out in effect tunes the I-beam / leaf spring resonance lower down. In the end, this is a more important aspect than the leaf or counterweight looked at separately I think.
I went through many such tests during the 80's and beginning of nineties, taking some of them up in the last years.
I didn't like the single leaf springs with my medium to low compliance cartridges, I preferred the double spring ones - I don't think I have a triple leaf I-beam.
There is another aspect of the I-beam, which is critical / sub-optimal: The weights are not centered around the I-beam, ie. it exerts an offset torsional force on the leaf. This means that any vertical movement of the arm activates a hidden torsional resonance, which slightly modulates tracking force. The vertical axis is the one axis, where you want *absolute* "true inertia", and as few resonant modes as possible, including arm resonances, as it affects the critical downforce.
My feeling is that the stiffer beams control this aspect better than the single leaf beam.
I always preferred the I-beam leaf with a bit more damping than originally provided, using BluTak.

For balancing I move two Blue-Tak "saddles" along the I-beam, and the arm lever extension, to keep lateral forces equilibrated.

My ET2, now with ET 2.5 bearing is an early one. I ordered the bearing for around 0.8 bar (ca. 11 psi) and it still runs OK with ca. 3 psi. Though below ca. 6 psi things go audibly downward, the magic disappearing somehow. In fact the ET 2.5 has "simply" more surface and is therefore already stiffer, but the price is a higher lateral mass, probably 10g more.
Sending the arm from Switzerland to the US - and parting from it - would probably affect my sleep... not in the best way. :-) It works good enough... I'm Just checking lateral balance after adjusting the VTA.

Slaw, could you tell me which of my post you find offending and maybe why? I have no problem with disagreement. But I know sometimes my tiredness of repeated misinformation pushes me for words that fit my feelings. :-/

Regarding your photograph, Frogman...
A real audiophile is one who looks first at the turntable and tonearm in the background. I - almost - did.
:-)

Hi ye all! Did anybody ever try a Decca in the ET2.5 (or ET2 arm)?
I once did with an ET one and was not blown away - it didn't quite fit, but this was with a rel. light subchassis turntable, which acerbates several problematic aspects: High horizontal, quite low vertical compliance (one third!). Subchassis resonance above the horizontal resonance frequency of the arm/cartridge system.
I assume, but don't know, that using the decoupled counterweight could help here really. The question being:
Which stiffness, which weight/distance.
My feeling with decoupling and the rel. high compliance in the horizontal plane goes into the direction of
far out weight, with medium to low stiffness spring.
But I'd like to hear of real experiences, not virtual ones, or concepts. Of the latter, I have enough myself :-)

Thanks a lot Frogman! The wiring is an issue for sure, but the EM-field situation is actually the cause, and the noise is the symptom. And the ET2 / wiring / Decca system seems to be very sensitive. What turntable do you use, and how close are other power supplies?

Thanks Ct0517 & BdP! I am wondering that the conceptually very similar London air bearing arm (based on the Cartridge Mans's Conductor arm), with similar wiring, and at least these four "naked" unscreened (or five!) wires without screen for about 15cms, is the recommended arm for the London cartridges. It want hum, I'm shure (not the cartridge :-).
I suspect it's something to do with a missing ground link from the arm to the preamp. Does the original ET2 wiring has a 5th wire? Mine certainly does, but I have a different wiring & routing to the original one.

Thanks Ct0517 & BdP! I am wondering that the conceptually very similar London air bearing arm was "built for London" cartridges... (based on the Cartridge Mans's Conductor arm) - it must have functionally similar unscreened wiring, at least these four "naked" unscreened (or five!) wires without screen for about 15cms.
Could it be that it has something to do with a missing ground link from the arm to the preamp - does the original ET2 wiring have a 5th wire? Mine certainly does, but I use a different wiring & routing to the original one.

Richard
Yes i have two twisted silver wires running left and right of the tonearm. They are mounted to the tube via three very small pieces of double sided adhesive foam strips, to hold the wires and prevent them from touching the metal arm tube. They "exit" the arm connection bending a bit up and then down in a wide radius to the plinth, where they are supported again with an adhesive foam pad. And there is a separate ground wire to one of the arm screws.
With careful wiring dressing the arm is completely free in movement, and very sensitive to the smallest lateral imbalances, as it should be.

Hi all - interesting bits & pieces!
Ct0517: interesting to hear more from internal design parameters of Bruces bearings. Some time I'll make photographs of my wiring etc.
Dover: The wire experiences are very interesting, as they are real findings. I'm not convinced however that the reason for the RF issue is solid core or silver, it could be the insulation environment of the wires affecting HF reception too, or the smaller wire diameters. As always the observations are true, the causes sometimes can be more complex than expected.
Were the silk litz wires individually isolated (HF litz) or just the whole bunch? (Besides HF detection / diode-property could also be a cold soldering joint, but I don't suppose that).
My turntable still has the original alu plinth (not too long anymore), but the motor is fed by batteries and the tt as such has no connection with the mains when running. grounding a "raw" alu plinth surface is a PITA...
The Deccas by definition have each channel ground connected ("matrix" summed through the vertical coil). So the ground loop is there for the small EM-field buggers to sneek behind and find. Luckily they oversee the possibilty under certain circumstances - but which? Hum is a dark asian martial art, teached under monumentally wound trees and learned by the nasty little buggers. There is some hope though in the light swords of master Yoda...
Your check list will be very helpful for many in trouble! Like a friend who messed up the ground connection on his new, outstanding phono stage, complaining about everything except his wiring arts.
- Generally, I find that one considerable advantage of low impedance MCs is that they don't need screening through bypassing / dumping external EM-fields through their low impedance.
It's certainly a drawback that exactly the type of cartridge that is more sensitive to capacitive loading - and therefore the sound of the dielectric too - needs screened interconnects. IMO & IME screening doesn't help the sound quality except for eliminating potential hum.

- ct0517: It's interesting what you quote about the wire loom. While radial tonearms have the advantage of leverage on the point where the wire exits the tonearm tube and enters the base (tube), the distance is short, and the wires are somehow uncontrollable in their movement, so they are inclined to rub / stick / jump - and this "out of sight". The latter problem is nonexistent in tangential arms, if the wires are properly arranged. Thales' Micha Huber prefers *very* thin wires (ca. 0.07mm), probably to have the arm movement as free as possible. If this is necessary "even" with radial arms, not even a trace of a problem will remain regarding freedom of movement will remain with such wires for tangential arms either. IMO even two twisted 0.15mm wires, carefully arranged, do not create a problem.
- Dover: The silk wires are interesting, as these have much more electrostatic "field" surface covered with natural insulation than the compared solid core wire, this might (on sinister or twisted paths) affect RF sensitivity...
Somehow a "better" insulation with thinner litz wires should be "capable" of better radio reception :-/ ;-) In this case: The opposite!
Isn't reality from time to time baffling us?
Actually it's more of a surprise if we actually and really *know* something for sure.
- Decca: I had a first try yesterday with a artisanally rebuilt Decca, in the Garrot tradition. Yes, it's still a bit of a hassle concerning hum and screening. My 1.25m unscreened solid core wires are too long, but the hum with one phono stage we compared yesterday was quite acceptable even in my suboptimal situation (the Lehmann Audio Black Cube).
The first results are extremely impressive - in a truly musical way. This cartridges liquidity, high resolution, ambience retrieval (not 1:1 = big spaces) and grainfree transparency is *hugely* impressive!
Yes, there is a slight upper mid forwardness (but still in the range of "realistic") and yes, there is a certain upper limit in tracing (now, in my present setup), which is slightly modulated by the very low horizontal LF resonance (not yet damped enough). I will experiment with different spring / counterweight settings.
Still my rebuilt Koetsu Black is - as yet - more general purpose, and extremely natural too, and as yet it traces better.
- Phono stages, in short: The Black Cube is good enough by far to show off the superb qualities of the Decca. It seems to sound better on MM than MC and it's good. The Lehmann was a trace gray on MC, but well organised, generally transparent, dynamically stable and transparent. I had some issues with the Koetsu on high level historical horns (on fff).
. The same issue on blasting horns did arise with an austrian phono stage from pure dynamics. This one was very good, transparent and open, with very good stage in all dimensions. The bass was very good too, and it was fuss free in setup. (It costs around or below 1000$)
. The real stunner was an older LFD MM0, same circuit as the LFD Mistral and later basic LFD phono stages (but with a much beefier power supply). While I had a big issue with some intermittent RF signals ( ;-), probably radar, it was truly superb in timbre, agility, space, musicality and dynamics with a very natural, open bass. My feeling is that the LFDs phono stages might be considerably underrated in the press.
. My Audio Synthesis Passion phono had probably an issue with the supply connections, resulting in a not typical slightly opaque and undedamped quality in the bass, and a slight haze. The Passion Phono was still very transparent and true to instrument characteristics with wide and high stage, depth was a bit shortened probably by the mentioned issue. Generally and over long years this is a superb Phono stage.

The real fun in research is the reality. It has a certain from time to time recurring character trait of disrespecting the holy truth of any hypothesis. Without that, life would be pontifical s***. :-)

Regarding RF: It was only a problem with one phono stage, that might have some issue in the power supply (while still sounding very impressive). The power supply is one of the places where rectification "happens" (yes, it does), the others are nonlinearities in active devices or shaky contacts. No problem even with ca. 1.5m of twisted non screened solid core wires. That's my experience in the context of my system.
Very important: I compared the phonostages with a superb insulation transformer that does a lot (by sounding like less devices in the signal path).
I placed a Stadler air cleaner / ionizer in my listening room, that ran for very few hours (1-2) but was unplugged while listening. After experimenting ca. three weeks with "high quality" water in a humidifier which improved the "atmosphere" or energy but made the sound somewhat dull. The results with the ionizer are amazing: Remarkably more full and transparent - and no charged LPs... !!
We suspected already during an earlier listening sessions, that the slowly increasing amount of dry air exiting the tonearm creates - a lot! - of static charge on the vinyl surfaces. And it had a considerable effect sonically. The ionizer, building up a certain reserve of air ions (smells also a bit like Ozone), seems to eliminate this problem. Hmmm...

The Decca continues to amaze - fantastic! And this already with the Lehmann Black Cube... :-)

Regarding EI (there are several other "square" cores BTW) vs. toroidal transformers: Things are not that simple. While a toroidal has the advantage of a more simple "flowing" magnetic circuit, it's main "advantage" is the absence of an air gap - an economic advantage. This makes for considerably less iron for a toroidal, and more inductivity with less windings. This makes for a low (ohmic !) loss transformer, with low impedance windings.
However this creates disadvantages: The saturation of a toroidal is very sharp, and with the industry practice (and the practice of almost all audiophile transformer builders) of driving the transformers too close to the magnetic saturation point of the cores ("Efficient" ! Bling!) they are *the* achilles heel of excessive sonic mains sensitivity.
And within these issues DC on the mains (a strong disturbance of high variability) drives a toroidal transformers very easily into saturation, a massive disadvantage!
The last related disadvantage of a toroidal is the inherently lower ohmic loss: It produces (much) higher charging current spikes, which on their own magnetize the (hard limited) toroidal core much harder, and again pull away reserves from the iron core. Low loss is not per se better, on magnetic circuits it creates very audible problems.
A correct air gap of a well made EI transformer (not the usual cheap chinese ones) makes it much more linear, and it absorbs DC on the mains with much less hickups. And yes, it usually sounds better.
As does a well designed "artisanal" insulation transformer with EI core.
One example more of reality vs. hype and hypothesis.
And a toroidal "out of reserve" creates very strong hum fields BTW.

In my system, there is a low count of transformers (and an increasing count of batteries). The LFD, with some hum and interference problem in our test, has toroidal transformers ;-) Close to my phono front end (1m) there is only one transformer plus the phono stage transformer, if there is one.

My LFD MM0 looks like it has the same circuit board as the LFD Mistral, but has a double mono power supply fed by a very generous toroidal transformer. It's switchable between MM and MC, it seems to sound very good on both inputs. I saw that one was sold on ebay for 275£, and another one advertised in spain vor ca. 310€. These are extremely attractive prices. Sonically, to my ears it plays well into the 2000$ phono stage league.

Transformer saturation is one of two main loss factors with transformers, magnetic and ohmic losses. The doubling of the power in high power amps with low impedances highlights the problem of ohmic losses. There are two questions about reducing transformer losses: Does it correlate with better sound, and at which output power levels? And which design optimisation has to take places with which compromises to reach the intended goal. Think also about the sonic qualities of single ended amps, some tube amps too with extremely good bass, but no doubling of the power to lower impedances. The optimisation of audio quality in the major signal range is important - even with considerably compressed music the main energy range is at -10 dBU rel. level, which means at one tenth the peak power. With better material it's rather around -20dB and more. In a normal listening situation one is inclined to reduce the replay level. Generally 90dB medium level, except peaks is very loud. My speakers need less than one Watt average for this. Everything that improves sound quality from zero up to this power range has a lot to do with sound quality. Doubling the power into half of the impedance would be desirable, if there were no inherent sonic compromises. I know this flies in the face of orthodox engineering, but there is some empiric and well thought through truth to it.
Reducing ohmic losses leads to an extremely high current path for the capcitor / rectifier path, with considerable problems, exacerbated by "stable, high energy" designs with huge load capacitance.
Interestingly one of the better sounding Goldmund transistor amps as well as some Cello designs did search for an *optimal*, not maximal load capacitance, with very good results.
One of the reasons is reducing the stress factor inherent in increasing charge current peaks with increased capacitance. The same design compromise is involved with low loss transformers.
There is a way of thinking (shared by some famous names) that a "transformer only provides voltage & current and has no influence on the sound whatsoever". If one starts to experiment with different (brand) transformers, one finds the opposite is true.
This has - in empirical evidence - strongly to do with the magnetic circuit, and wire diameters (and rectifier and power supply design). This is a wide - empiric - research field of patient work, which very few people have done from both sides, the producing and listening side. Most any "normal" transformer is built following general design rules, strongly economical ones, which overlook some key factors, which are relevant "only" to audio. Optics are sometimes also optimised.
It's BTW a question too, how desirable a wide bandwidth is for a power transformer, which is an inherent property of the general winding technique of toroidals.

- Ct 0517: The funny thing with ESLs, Quad etc. is that they do much better with something closer to a current source, this means they deliver much more voltage on high impedance than a low one. Doubling the power in each halving of impedance is the definition of a perfect voltage source. A voltage source gets tricked out on the voltage increase needed for the bass impedances (except if one uses insanely powerful amps). And it delivers the current in the highs (doubling, doubling, doubling the power) like a preussian soldier by executing it's order - but there is an intrinsic stress in that, of which thermal stress is not the least.
There were some highly regarded german SS amps that worked as a current source. It's a pity I never heard one or could try one.
So you listen on Quad ESL 57?

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?

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.

Hi Chris! The magnet damping doesnt't work the way you describe it. What you describe is the magnet "levitating" of the Verdier (and others) by opposing magnets of same polarity.
The proposed damping works by eddy current, the same as eddy current brakes. Basically you put a magnetic circuit very close to a electrically conducting surface. The magnetic flux crossing the surface induces a current in the conductor / surface, which creates a counteracting magnetic field.
I placed a neodymium kitchen magnet (or two) on a blob of BluTak underneath and very close to the spindle. (I like my setups to be a bit messy - but reversible :-).
My wires exit the arm relatively "straight" at the end of the tonearm proper, the magnet is on the opposite side of the bearing.
The small round kitchen magnet has a magnetically conductive (steel?) "guiding" sleeve around the magnet that guides the back side pole to the front, so you have opposite poles in the center of the magnet vs. a circular opposite pole around.
In my case it works "enough", so that the arm has no high Q lateral resonance. It's probably still slightly underdamped though. Which is IMO desirable as a trade-off.
I don't have an alternative anymore, as my oil trough is leaking.

a) regarding wiring: I have to try again to photograph - the lighting makes pictures difficult... patience :-)
b) Fridge magnets & damping: Drop a circular magnet into a vertical copper tube. An enlightening sight - the magnet centers itself and *creeps* down very slowly instead of passing quickly!
Magnetic attraction is needed for static force only or for DC so to say.
With movement or "AC" the magnet induces a current into a close conductor (for which alu is moderately good), which creates a counter field, ie. a damping action. OK :-)

Chris

So just a question.
Bass waves are slower than all the others. So why do people put subs X feet behind their mid and tweeter drivers ? Just asking.

If I was you Harry I would be very tempted just "temporarily", to set up in near field for one hour - just to hear what was possible with one sub.

I’m not exactly shure what this would mean? More upfront placement = faster bass?
Placement is a question of "allowable" phase angles between drivers caused by offset drivers (specially in distance to the listener). As long as this offset phase angle is not far off, there is no "real" problem.
Bass waves travel at the same speed as any acoustic wave in air, but have longer wavelengths, so offset distances in the low bass can be considerable without being audible. Usually it’s said to be desirable to be below 90 degree - I’d keep it lower, to be on the safe side in the cutoff region where the subwoofer is still emitting considerable upper bass levels.
At 40 Hertz xo this would still be 67cm for a quite tight max. 30 degree difference. This results in an allowable 120 degree two octaves above, at 160Hz, at eg. -24dB (for 12 dB/oct.)
But I agree, that close-field placement is the preferable "error", because a) the excursion / level of the subwoofer can be considerably lower, b) the decrease of room reverberation level relative to the direct sound level should reduce audible room resonances & bass colorations = c) the modification of the subs frequency response by room resonances drops an order of magnitude.
But... it works only if there is no spurious midrange energy exiting reflex tubes or coming from the driver. Still - the lower sub levels reduce distortion and "box talk" & "cone cry", both help.

Re/ VTA & gooseneck range not high enough: Having a BSc in audiophilia nervosa including a MSc in empirical material testing... :-)
I'd propose a surprisingly crude idea, which might work better than it should. Have a carpenter (or your right hand :-) make a wedge formed piece of wood - good sounding wood like solid fir or similar, or maybe also birch plywood. The wedge is placed between the ETs headshell (doesn't need to protrude from the wand) and the cartridge, covering not more than the interface between your cartridge and the arm wand. The wedge corrects for the back tilt angle of the arm if the manifold and gooseneck are in middle & correct positions. Maybe the wedge is 2mm front and 4.5mm back - make a drawing and calculate the height correction.
You could glue the wedge to the cartridge with a bit of white glue / elmers glue which doesn't hold to metal all too well. This makes an easily breakable connection. The other side (either to the arm or to the cartridge) uses screws - or maybe even thin double stick tape. *Not* having a totally rigid connection with natural materials in the "mechanical loop" often sounds more natural.

Regarding arm boards and optimal materials, it's very interesting to watch the diverse experience in idler drive plinths. A mixture of natural and slightly lively wood layers, combined with *some* more deadened materials, like *a bit* of MDF and maybe one layer of stone seems to yield very good results. Pure MDF not, neither Corian, synthetic stones, marble or metal is desirable. I think a considerable part of this experience should be considered when thinking about armboards. Solid wood and *maybe* a bit of acryl or alu smewhere should work well too.
Personally I'd seek other materials than overdamped polymers like Sorbothane - it's sounds like s*** as a platter mat, and it's audible wherever one uses it. Even natural rubber feet on speakers (or under analogue decks) sound IME sluggish. It's easy to overdamp surfaces and overtighten connections (not only because of eg. making cracks in the ET structure :-). Both result in kind of a deadened, "negative feedback" kind of unnatural sound.
Solid maple? A friend uses solid oak to very good effect for the adanalog arm.
For ET arms maybe solid sBruce is the optimal wood...?
An eminent discovery.

Hi Chris! I accidentally grew up with a Lenco B55 (practically same technology as L70/75/78) and a Thorens TD 124. These were the first victims of my brothers and my audiophile interests - we dismounted and reassembled them. I was more impressed by the ingenuity and elegance of the Lenco - *and* I still remember the sound as very upbeat and vivid, memories reaching almost 55 years back! Much more so than my slightly lukewarm memories the TD124, I'm sorry to say...
The Lencos plinths empty rooms are not for controlling resonances - they are for ventilation, as the motor, a shaded pole motor, has very low efficiency and consumes *35W*...! I rather think that in the end this is more of a weak point than the idler wheel. My impression is that the vertical low mass idler wheel is (within the context of idler wheels) a very good idea. The weak point there is a) the steering of the wheel with kind of a rod with limited stiffness and b) the exact positioning relative to the conical axe of the motor. But...
Rehearing the L75 in a friend's (superb) system with modded Avantgarde Trio etc. etc., after years of listening to a Well Tempered Signature, then a Funk tt with Funk arm was a revelation - already with a simple plinth. Of all "real existing" turntable platforms it is in musical, timbral, dynamical and coherence terms almost in another league - and it is a "stone age" concept. It really was a jaw-dropping experience. ca. 1980 I *never* considered re-using a Lenco or a SL1210). I was a *real* audiophile, who had to use a belt-drive... I bought a Thorens TD 126 - one boring lifeless turnatble. Then came the Rega 2, then a Walker CJ55. Both really much better in musical & colour-terms, then the WTT Signature in my system too.
Funny how  I moved from "scientific" musical medicine back to "evidence based" or empirical musical medicine.
Today I use a much modded SL1210, which has a slight advantage in purity / stability of upper midrange timbres.
In Europe Pet Reinders is the Lenco "guru". I can do without gurus, though he has a good solution for the basic motor / bearing platform.

those nasty motor wheel - rumblings.

I was actually amazed about how they disappeared behind the not inconsiderable LP pressing and cutting lathe rumble (the latter sometimes audible too), and behind the superb musical information & drive. I expected problems, but...

armboard holes are helping to provide tonearm isolation

I assume Jean Nantais has pretty good reasons and convictions why he does things the way he does.
But - looking at physics - how could these holes provide isolation from either acoustically transferred noise (which, if they'd change at all, would rather increase) or structure borne noise.
Besides: How does it sound?

Hi frogman, I share with you the admiration for Paul Desmond. I play the alto myself and he has +/- my ideal sound on the instrument (within the limits of my abilities, and the recorded sound as you point out).
Loading MCs: Your line of thoughts reminds me of my experiments  with the Magnepan MG3 speakers with their superbly transparent, but often a bit glassy sounding tweeter. I started with the usual recommendation to put a "normal" resistor in series, but this was loosing much too much transparency (a noiseless back-ground with kind of a plentyful sea of lively information). Then I used parallelled  ERO Resista metal film resistors, but the effect was not much better. Then I replaced the HF-Litz feeding the ribbon with a thin solid core wire and had success with more transparency and less "noise" and brightness. Ultimately I developped an independent, three-wired new crossover (with soldering to the ribbons... :-) which somehow integrated the superior mid/high transparency of the two-way MG 2.5 (and MG 2.6) into the three-way-MG 3.
Before these changes I had the feeling that my Koetsu Black / VdH 1 needle (Gyger upgrade) was sounding "bright".
Removing the transparency obstacles, which created stress and brightness, allowed to retrieve the VdH1 stylus information without glassyness.
I am skeptical of loading as a cure for problems created elsewhere, it's not really working in that context, it's too much of a compensation game (for me). I loose too much, gain not much.
Besides: The direction of the resistor is as audible as that of cables, as is the brand and type of resistor (and the preparation of the wires and the soldering including the solder).
To attain an experimentally "clean lab table" for these kinds of comparisons, within the context of the ultimately almost always slightly sloppy way people generally do their comparisons, seems pretty optimistic to me.

@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...;-)

Frogman, I can only second what you wrote! To hear the elimination of contacts or to compare different connectors under controlled listening tests has been my most educating experience in audio. I think the effect of contacts on sound quality are highly underrated. I guess that from the omnipresence of brass based "professional gold" contacts in a wide field of the audiophile market. Listen once, never return back.I was an anti-WBT low-budget "snob" :-) but the copper based WBT RCA connectors and the Clearaudio MPC were hugely better than any silver- or gold-plated brass connector back when I compared these (with ca. 7 identically constructed & oriented silver interconnects). Yo don't get what you haven't paid for - except for soldering directly!

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.

Regarding pumps and pressure:
a) Back in the 80's I found that the WISA 300 "high pressure" model (of which I bought several, directly from the company) was a single membrane pump, not a double one like the original HiBlow. My high pressure WISA model dropped in actual measured pressure level at the arm below the HiBlow, and had a high variation of pressure (mains frequency) - and the needle vibrated. This resulted in a "homeopathic 50Hz drone" that subjectively gave more, but a slihtly tubbier bass - this was *with* a ca. 7.5l tank.
b) I then chained two HiBlow pumps, ie. I hot-glued a piece of silicon tube to the inlet of one pump and to the outlet of the other pump. This resulted in (if I remember correctly) ca. 0.45 Bar (6.5 psi?). Three pumps were around 0.6 Bar, all this sounded very good, and was more silent  than a WISA pump. The HiBlow has a surprisingly steady flow and it's limitation can be surmounted by chaining two or three. On the ET 2's "normal" low pressure bearing the two HiBlows were a remarkable improvement.

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. 

This is indeed the way I tested this. Stylus in groove, platter stationary, pump running, phono gain turned up. In this test the HiBlow was audibly quieter than *my* WISA 300 high pressure.

Hi John, no, your WISA pumps work the same. But connecting them parallel and out of phase makes them work the same way as a double diaphragm pump, like the original HiBlow: Single ended vs. push-pull... The air pressure is much more constant, "stabilized" pressure being about the same as the pressure peaks of a single WISA.
How high is the pressure? I assume it’s still not much higher than the original pump, and the worse noise/vibration is remaining. Besides I was not able to connect WISAs in series (nor will such a parallel combo), contrary to the HiBlow pumps with their air-sealed housing, which allows operating them above normal atmospheric pressure.

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.