Hi everyone,
Sounds like you all had lots of fun and gained some insight regarding the importance of proper turntable drive systems. Be it rim, tape or direct drive, it's about the right amount of torque vs platter mass with both the compliance of the link: belt, tape, idler( and consider the flux lines in a direct drive arrangement as a compliant link too!) and the frictional losses(bearing surface area, oil) being additional factors in this "equation".
I heard Chris' 380 prototype in march and realized right away that with some additional work, his effort would yield spectacular results. Can't wait for the finished version. RMAF, Chris?....
The Ref.arm that Thom uses has slightly too high an eff. mass to be ideal for the Universe, at least when the cart features the silver base plate. Tonally it will complement the Airy 3 better, since ebony has about the highest high frequency resonance damping properties of all woods suitable for making armwands. You may consider this somewhat of a sonic fingerprint. So pick the right cart(ZYX Airy 3, Lyra Helikon, even an Audio Technica AT OC9 - you get the idea...) and the combination will work like a charm, as long as the fres doesn't end up being too low(it would be difficult to build an ebony arm with an eff. mass below 15gr. without sacrificing stiffness).
Some time ago I tried to post a looong treatise on the correlation between arm design and the perceived differences in bass "authority" and dynamic "attack" between Unipivot, gimballed and "no"-friction-bearing arms. It never got out(moderator, did I do something wrong?). In part I was trying to explain how high frequency structural resonances can lead to the impression of a "faster" attack, just as a heavy bearing structure(often found in more "modern" unipivot arms) store and re-release energy to give that extra(exaggerated) punch on the bottom.
The Triplanar is an excellent gimballed design(if I may say so). Since the energy path is broken up("split" armwand) and the actual moving part has low mass(meaning actual mass, not inertia), it's bass reproduction leaves little to be desired.
The top end of the Triplanar is not entirely free of resonances which manifests itself not in a grainy or ill defined character, but in a slight tendency towards accentuating the leading edge of the note while foreshortening the trailing edge/decay of a signal, slightly diminishing "bloom" or the so-called harmonic envelope of an instrument.
The ZYX Universe is a great, marvelously coherent, musical performer, but also not entirely neutral. It slightly rolls off the top end and it is not as fast as some other contenders, namely the Lyra Olympos SL. It's presentation(particularly the midrange) is nevertheless very lifelike, seductive without being Koetsu-"juicy".It is this trait which make it an excellent match with the Triplanar, so I agree with Thom completely.
Now, a harder wood, with less high frequency damping, like the Jacaranda armwand(also lighter than ebony) featured in Chris' Ref. arm will give you just what is required to work perfectly for the Universe. I had less time than usual to finish the arm for the open house event. So the armwand has only about 15 coatings of oil instead of the usual 50-60. The result: a great match with Chris' Universe.
I've said before that the choice of wood is not one of sound and I'll stick to that. As a designer I'd rather hear what the cart does instead of building it's sonic mirror image. A user usually has a different goal.
But the treatment/damping difference shows how profound the influence of resonance control(armwand and elsewhere, quantitatively and qualitatively) can be. And how critical component matching even at this level is to get the most in terms of musical satisfaction out of it.
Both Thom's and Chris' tables will provide just that: utter musical satisfaction when partnered with the right arm/cart combinations. And if I had to decide, I'd do as my wife does:
"Honey, I bought both handbags".....(her only weakness ;-)
Right, if I had the money and space :-(
I'm well aware that this post might draw all sorts of criticisms/flames or "yeah, he had to defend his product again" replies. Please take it as no more than a personal rambling, a string of thoughts written down to make an excuse for myself for taking a break from work.
And for Dan ed:
Before I forget, the VTF finetuning feature can be added/ordered for all my arms, not just the DPS.
All the best,
Frank Schröder
