TW-Acustic Arm

Hi Jaspert, I have had the chance to listen to the TW 10.5 on two occasions. Both in private set-ups ( one on a Raven AC ) and with familiar cartridges (Titan i and UNIverse).
However - I do not think that anyone here would really appreciate my comment. Looking back in this thread and reading some of the posts here we can generally assume, that I have little clue and certainly are unable to appreciate or judge a great component anyway.
My prejudice was largely regarding the praise in advance - before any test or listening took place.
Did it sound good to me ?
It did not sound bad.
Pretty balanced, controlled, good and fast upper bass, nice integrated lower midrange. Good staging, not too detailed. Reproduction of height was a bit limited, but width and deep pretty good. I wished for a bit of more "air" and inner detail. This could be an issue of internal wiring maybe.
Bottom octave was not as good and fast as the upper bass - but then you rarely get that at all.
And hardly any speaker or woofer can show the picture.
It did however hold its own against a few other top-flight tonearms of today. But it did not outperform any of them either.

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Dertonarm: "My reservations with either tonearm is the amount of bearings and moving parts involved in these designs. My reservations here are about energy transfer and the rigidity. But I will soon have the change to work with the Simplicity in person, - as I have already done with its big brother the Thales last November."

I think that's the Archilles hill of tonearms like that; too many bearings and moving parts and the lack of rigidity. Having a pivot point right above the stylus have the potential to introduce unwanted noise, obviously. Another concern I have is the vertical geometry. I know the Thales Original arm (the designer certainly is inventive in naming tonearm names :) ) is capable of zero degree tracking error using the Thales theorem but a pivoting headshell can introduce vertical error, unless the record is absolutely flat, since at the armbase the bearings are not capable of compensating the constant changing headshell angle, unlike a gimbal arm with the bearing angled approximately 23 +- degrees, so it can be very sensitive to VTA and azimuth adjustment - because microscopically they are constantly changing - also compounded by the fact the armwand is very short. The guiding arm, part of the Thales triangle, which is very long and pivot horizontally AND vertically and the vertical plane has to be below the main arm to minimize skating force otherwise it would swing down, adding inertia. I believe the guiding arm is where a linear motion bearing might work better but the insistence on avoiding linear bearing is its selling point. Overall a very clever design and looks to be well executed like a Swiss watch, as the designer is, not surprisingly, a watch maker. The Simplicity is rather more elegant and only sacrifice a tiny bit of tangential error. Please report more of your findings on these interesting arms and preferably on a new thread.

Sorry to hijack this thread with the post. I will quietly go away now. Please continue with discussion on the Raven.

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Hi Dertonarm,

Thanks for giving some context to your impression on the said arm. Balanced view i thought and I appreciate that.

Things do tend to get a bit headed between the TW fans and some detractors so you get a lot of noise in a big thread.

Hiho, no need to leave - we never actually had a discussion about the Raven TW tonearm here. Your questions and remarks regarding the M. Huber tonearms were about the only ones about tonearm design in this thread.

The Thales/Simplicity tonearms design do indeed focus on the zero tangential error. But to me it seems a bit like jumping out of the frying pan and straight into the fire.
So far my impression is that the mechanical (and therefor the sonic ...) trade-off for close to zero tangential tracking error is way too high. The increase in moving parts and bearings does heavily interfere with energy transfer and rigidity.

Yes, - how about someone opening up a thread about zero error pivot tonearms in general or the Thales principle tonearms in specific ?

I will venture a comment on the Thales principle.

It seems to me, neither a trained physicist nor engineer, that the best and highest purpose of a Thales-type design would be to create a high inertia mass at the end of a tonearm and hang a cartridge off it. If the high mass headshell mass had an EXCELLENT horizontal bearing, A-N-D the record was free of warps (and perfectly centered around the spindle hole), then the concept should work very well. The real problem is that...

a) with a light headshell which allows the arm to deal with vertical plane issues, there are inherent weaknesses in the coupling of parts in the arm.

b) with a very heavy mass and rigid arm structure, the cantilever of most carts (and the inertia of the headshell mass) would mean that warped records would have problems.

That said, with vacuum-held flat records, or records put through the "Record Flatter" that concept has real potential merit (as long as the hole is not off-center).

Nuf said for a guy who don't know...