I have found and copied the review from
The Absolute Sound with my response and a few comments:
The Odyssey RPI-XG
The Odyssey RP1-XG is a departure from conventional design
approaches and seems to embark upon a sonic path different from that of other
arms In the survey—an intriguing and (potentially) valid path. I am of two
minds about this arm. I love it and I distrust it. This is going to drive the
manufacturer crazy and give my critics ample ammunition to swipe at me, but
only If they choose not to explore the complexity of the dilemma. The Odyssey
sounds wonderful, has no gross aberrations in tonal balance—and yet I question
its accuracy. Possibly, just possibly, the Odyssey is a significant advance in
the state-of-the-art that is marred by subtle problems hard to pinpoint.
What does it sound like? A tonal balance similar to the
Syrinx PU-3, with slightly more low frequency impact. Rather than the
incomplete tonal body of the Syrinx, the Odyssey has a rare completeness of
tonality, from top to bottom. The effect is like taking the Conrad Johnson
Premier Three's midrange and extending that character to cover the full range.
There is a brilliant vividness of tone that is emotionally powerful. It sounds
like live music. It adds a luster to every record in my collection, which would
normally indicate a midrange prominence; but I detect no prominence of the
midrange at the expense of the extremes. The sound is addictive. So what's the
problem? The soundstage. That's my problem with the Odyssey. The soundstage is
very forward with a serious lack of depth. Yet, it is wide and there seems to
be good focus. But there is very little distinguishable ambient information.
The other arms set up the soundstage environment and the performance takes
place therein. With the Odyssey, there is no stage set; the Odyssey is the
performance. Seemingly, the Odyssey is recovering the ambient information
(hence the full tonality) but is not separating it from the initial sound
source. I don't claim to understand this, but that's how it sounds.
The oddness of the Odyssey's sonic performance compels a
more detailed, objective discussion. The Odyssey is a gorgeous looking arm with
unique design approaches. The most troublesome aspect is the looseness in the
bearings. Yes, in three separate arms submitted to TAS there was play in the
bearings. A letter from the designer informed us that the loose bearing was
deliberate because too many bearings were being rejected by quality control
because of brinneling. So, Odyssey loosened the bearings to avoid that problem.
Odyssey's position is that the mass of the arm controls the energy. I agree, as
long as it is an energy above the arm's resonant frequency. Below the resonant
frequency, the bearings must be tight to control the energy or, as you will
remember, chatter can set in. This simply cannot be good for the sound. As a
reviewer, I must express my disagreement with the manufacturing choice here.
The Odyssey comes with gold-plated screws, counterweights, and mounting base. I
would rather see the money spent on tight bearings with no brinelllng. On the positive
design side is the location of the bearing in the plane of the stylus. Also,
there is the unique asymmetric configuration that terminates in spherical
structures that are said to cancel standing waves in the material. The bearing
housing is offset at the angle of the headshell. The headshell is also unique—a
solid triangular block that may well be effective In handling energy generated
by the cartridge. Unfortunately, the headshell does not and cannot have slotted
holes. The stylus tip to pivot distance remains the same, though, because
overhang is adjusted by rotating the eccentric mounting structure. A clever idea
that overlooks the change it causes in the geometry because it is altering the
pivot-to-splndle distance (a dimension that is just as important for proper
alignment).
In summary, the objective Odyssey is a combination of
unique, innovative, though sometimes questionable, design choices. This makes me
wonder if the fullness of tonality is a successful attribute of the Odyssey's innovation
or a pleasant distortion resulting from design flaws. Can the soundstage
problems be solved without losing the full tonal body? They must be. If the
unique design of the Odyssey is to be validated. I sincerely hope so. One last
note. The Odyssey had to be used with its own cable. I'm trying to get new
cables made to see if the soundstage problems are hidden therein.
Tom Miller
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My Response:
2.1.85
Dear Tom,
I have been reading your special report on the 5 tonearms.
Thanks for the favourable comments, especially the one about the RP1 making
your recordings sound like live music which to me is what it's all about.
Regarding imaging, output leads do indeed make a
difference, and the leads currently used in the RP1 are actually due to be
replaced. This aspect of the arm is one which we have been looking at since
before last January but have encountered a number of problems trying to source
a suitable cable and universal connector without adversely affecting the retail
price. Perhaps I should also be looking at a possible flexible mini
interconnect which would allow standard interconnects to be used. In any
case a revision of leads is in the pipeline.
Another change is in parts sourcing and assembly sub
contractors which will allow tighter tolerancing of components and closer
tolerances in assembly which will mean in turn that bearing play can be
reduced, since new packaging will ensure that no damage to the bearings occurs
in shipping the arms which can be a problem.
To recap on the geometry, Tom, you are correct in saying
that the arm pivot to platter centre distance is important, but it is you, not
I, who have overlooked something. The thing to remember is that all the
parameters are interdependent, inasmuch as once the limits of the inner and
outer groove are established and consequently the zero tracking error points,
then a change in either arm pivot to stylus length (L), or arm pivot to platter
centre distance (D), or the offset angle (A), will affect the other two. The
overhang is simply a function of L and D.
In a normal slotted headshell, the reason for the slots is
to enable the cartridge to be adjusted such that the length L is correct, for a
given angle A and distance D, which are determined by the manufacturer and the
armboard mounting respectively. In the RP1, there are no slots, so L and A vary
with the cartridge. Consequently D has to be able to be adjusted which is the
purpose of the eccentric mount. Please see the accompanying sheet for diagrams
and calculations. Perhaps you should incorporate a précis of the basis of arm
geometry in your second part so that your readers can more fully appreciate the
reasons for the various differences in setting up, and if you could mention
that I haven't overlooked anything with regard to the RP1 geometry then I'd be
most obliged. Perhaps your editor would consider a feature at greater length on
the subject, as it can get a bit confusing.
Regards from Scotland.
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[Check out my post on SME geometry if you want to learn more and see where Tom Miller's misunderstanding occurred. He was and is not alone in this. I have seen comments not just from reviewers, but also from well respected designers and manufacturers which show they also didn't understand it. And compare the Stereophile article to see how a different reviewer perceives soundstage and imaging.]
