New Lyra Delos Cartridge


Hey guys,

Just wondering if anyone has used the new Lyra Delos Cartridge and what their thoughts were on it. I saw it on their site and on music direct.

Thanks,
Russ
rhohense
Dear Nrenter:

My observations have been that you can get pretty far in engineering circles by simply being able to "see the obvious" (smile). Actually, once you understand the underlying rationale and logic, the majority of engineering decisions should appear obvious, as properly defining the problems and issues is what gets you the majority of the way to formulating a solution. The catch to all of this is that many things are obvious once you grasp the underlying logic, but are elusive until you grasp that underlying logic (grin).

For example, consider the spindle and bearing design on Bill Firebaugh's Well-Tempered turntables. Somewhat like the Delos' mechanical pre-biasing system, the WT bearing is designed deliberately to place the spindle in the wrong position and wrong configuration under static load, precisely so that the dynamic load of the rotating belt will force the spindle into the right place and configuration. Once you understand the Well-Tempered's logic it is a very obvious thing to do, and given the simplicity of Bill's implementation the feature could have been incorporated into a belt-driven turntable from the 1960s if the designer would have had the insight. But did anyone do this before Bill Firebaugh?

>the design goal of symmetrical magnitic flux in the gap with an optimal tracking force applied seems intuitivly obvious to the layman.

I will point out that the magnetic circuits in traditional-style MCs do not even have symmetrical magnetic flux across the gap, as the asymmetrical positioning and proximity of the magnet exerts a warping effect on the flux-lines. The first challenge is therefore to design a magnetic circuit that has as symmetrical magnetic flux across the gap as possible, but that requirement by itself eliminates the majority of MC cartridges.

Regarding the novelty of the Delos' mechanical pre-biasing system, because I fully agree that it appears to be an obvious design feature (in retrospect of course - grin), I have discussed it with various Japanese cartridge designers and audio reviewers (some of whom have a good overview of the entire cartridge industry, including historical perspectives). The closest that I got to hearing about anything similar was with Matsudaira (formerly with Supex, Entre, Audiocraft, and now with his own My Sonic Labs). Although Matsudaira didn't specify exactly what he did, he said that he had tried to achieve similar goals with a few prototypes that he made many years ago, but chose not to take it beyond the prototype stage. I surmise that his magnetic circuit wasn't capable of creating sufficiently symmetrical magnetic flux across the gap, which reduced the effectiveness of the mechanical pre-biasing system, and made the project appear (to him, and at that time) to be not worth the extra effort and cost.

Regarding the entire cartridge industry, it appears that the focus has been primarily on achieving the correct VTA and SRA, and the angle between coil former and magnetic circuit under VTF-loaded conditions hasn't received the attention that it deserves (I haven't been able to find any previous article on this subject, whether in German, Danish, English or Japanese). Also, my experience has been that the coil former angle is quite sensitive to VTF amount, so if the cartridge manufacturer allows the user a fairly broad VTF range, we can deduce that most likely the relationship between VTF and coil angle (and by extension, the desireability of keeping the coil former and magnetic circuit angles as tightly aligned as possible) isn't a priority for him. In contrast, I'm stipulating a 0.1g VTF range (1.7~1.8g) for the Delos.

>what were the engineering challenges you had to overcome to put this approach into practice?

First is that the mechanical angles of the body structure will be a few degrees different from any of your designs that don't incorporate the mechanical pre-biasing system, so you will create a fair amount of component incompatibility among your product lineup, which normally is something to be avoided in manufacturing (particularly if you maintain large component inventories).

Second is arriving at the right combination of shape and elastomer hardness for each damper type, which is essential when progressing from theory to practical implementation. A key part of the mechanical pre-biasing idea is to consider the damper deformation due to vertical tracking force as an asset rather than a liability, and aggressively take advantage of it. But since the rate of damper deformation per unit of tracking force is influenced by shape, thickness and elastomer hardness, if the elastomer compound or thickness changes, so will the damper shape. Since a cartridge builder relies on a variety of elastomer compounds and thicknesses for different cantilever materials, coil metals, suspension wires, body material and structural choices, frequency ranges and so on, and also since good-sounding elastomers are not known for being particularly precise or predictable in terms of mechanical behaviour, extensive trial-and-error testing will be required. I believe that we went through over 50 different combinations of shapes, thicknesses and elastomer compounds before settling on the damper choices used within the production Delos'.

Third is that the suspension and dampers in a normal cartridge are non-directional, which means that the builder doesn't need to think about which way the dampers face or point. But since the Delos' mechanical pre-biasing system requires directional dampers, the cartridge builder needs to make sure that each damper faces in the right direction, and he must also rotate each damper until he finds the precise orientation that gives the proper amount of cantilever deflection for the target tracking force. Cartridges of this type are more demanding on the builder's abilities and attention to detail, and will take longer to build and adjust than a normal cartridge.

BTW, yesterday all of the printed instructions arrived, so we got busy putting everything together and writing export documents for our very first Delos shipment. We shipped out 29 Delos' yesterday, and more followed today.

kind regards
Great news.....I hope that some will be going to Music Direct....I want my Delos Santa :-)
I completely understand - You do not know what you do not know, until you know what you do not know, and only then can you make a guess if it really matters. :)

Do you believe the primary role of VTF is to align the coils & iron core within the gap, or to facilitate sufficient stylus / groove contact for proper tracking? And if the primary effect is to align the coils & iron core within the gap, I'd assume your dampener materials / suspension design / stylus geometry were selected to optimize tracking at the precise load to align the coils & iron core within the gap?

And given your narrow range of VTF (and subsequent VTA) to align the coils & iron core within the gap, did you take this opportunity to help users ensure a proper SRA during setup (i.e. if VTF is within tolerance, and, for example, the head shell is parallel to the platter under load, VTA - and therefore SRA - will be optimized)? Given your necessary design tolerances, I'd think this would be plausible.

Thank you for indulging my questions!
Dear Nrenter:

>You do not know what you do not know, until you know what you do not know, and only then can you make a guess if it really matters. :)

As a designer-engineer, one needs to be able to come up with a steady stream of new thinking and new technology. What is harder is to know in advance what will make a big contribution to the sound, as opposed to parading new technology for new technology's sake. The answer is to have lots of ideas and filter out the mediocre ones at the prototype phase. Not particularly efficient, but it works.

>Do you believe the primary role of VTF is to align the coils & iron core within the gap, or to facilitate sufficient stylus / groove contact for proper tracking?

Both. The importance of VTF in maintaining sufficient stylus-to-groove contact for good tracking cannot be downplayed. But it is also true that VTF _can_ be an important tool in aligning the coils to the magnetic circuit. OTOH, with a conventional symmetrical damper system and body structure, it simply isn't possible to get the coils aligned to the magnetic circuit with VTF applied (as should be clear if you study my pdf on the audionord website). Even applying a little VTF introduces an angular alignment error, and the higher the VTF, the worse the error becomes. Either the cantilever mount needs a mechanically pre-biased suspension and damper system (like the Delos) so that applying VTF will bring the coils into alignment with the magnetic circuit, or the body structure needs a special design so that the magnetic circuit can have a different angle from that of the cantilever mount.

>I'd assume your dampener materials / suspension design / stylus geometry were selected to optimize tracking at the precise load to align the coils & iron core within the gap?

Absolutely. The damper shape and compound, suspension alloy, diameter and length, and stylus angle were all selected so that proper tracking would be achieved at the same VTF as required to make the coils aligned with the magnetic circuit. However, also note that damper hardness and therefore angular deflection will change depending on ambient temperature (this is true of most cartridges). If the temperature drops you will need to increase the VTF to keep the coil angle aligned with the magnetic circuit, and if the temperature increases you will need to decrease the VTF to achieve the same. I normally recommend for the user to keep a small incandescent lamp and thermometer in the vicinity of the tonearm, and use that to control temperature as well as maintain good visibility. Target temperature should be 23~23 degree centigrade.

>And given your narrow range of VTF (and subsequent VTA) to align the coils & iron core within the gap, did you take this opportunity to help users ensure a proper SRA during setup (i.e. if VTF is within tolerance, and, for example, the head shell is parallel to the platter under load, VTA - and therefore SRA - will be optimized)? Given your necessary design tolerances, I'd think this would be plausible.

Yes, you have it right. All parts in the cantilever assembly were designed and all tolerances specified with this goal in mind. If the tonearm bearing height is positioned so that the application of the recommended VTF aligns the tonearm pipe so that it is parallel with the LP surface, the cantilever of the Delos should assume a 20-degree angle to the LP and be perpendicular to the red piece that carries the front magnet, and the stylus should have a 1-degree (+/- 1 degrees) rake angle to the LP. At least whenever I have set up the Delos with proper tonearm bearing height and proper VTF, all of the other angles including VTA and SRA have more or less fallen into place.

The Delos incorporates another unique but IMO sensible feature which is intended to facilitate proper cartridge alignment in the tonearm headshell, the body structure makes greater use of non-parallel surfaces to better control resonances without relying on excessive damping which could rob the sound of dynamics and immediacy, the instruction manual discusses in-depth what cartridge loading does and how to achieve suitable loading, even the packaging box was designed to be more interesting to look at than normal. It will be fun to hear what Delos users think about all of this.

>Thank you for indulging my questions!

No problem. As you can probably guess, working on the Delos has been a fun and educational experience, and I hope that some of that spirit is reflected in how it sounds and what it is like to use.

cheers!
Mr. Carr,

You have been very gracious with your time and your candor. Your insights are not only interesting, but also very informative.

I would be curious to know about some of the ideas / technologies you discarded as you finalized the Delos design, as they did not provide the benefits you intended, or because they will be saved for other cartridges (due to the monitary costs to achieve the experienced benefits).

Also, how do you select your stylus profiles for your various cartridges?

You are very crisp with your technical specifications, however, you openly offer a wide range for catrige loading (100 Ohms to 47 kOhms). Why such a range? What specific impedance would you suggest for the Delos?

I like the suggestion of the incandescent lamp and thermometer to help moderate temperature around the cartridge. Thank you very much.