TONEARM DAMPING : DAMPED OR NOT ? ? USELESS ? ? WELCOMED ? ?

Raul,
Congratulations for picking another fascinating and controversial topic for discussion.  I intended to sit it out because there is no single solution to your puzzle, but decided to chime in with my opinion based on some measurements and experiences with two different set ups.  First set up:  Arm, SME Series III.  Cartridge, Shure V15 Type V MR.  Test Record used, Shure ERA IV.  I know you are aware, but for the record this was a high compliance cartridge and a low mass tonearm, considered state of the art back in the day by Gordon Holt among many others.  It still sounds very good mounted on a VPI HW-19.  Anyway in setting it up first without damping fluid in the trough, and then with damping fluid in the trough there was very little difference in tracking ability leaving the VTF at a nominal 1 gram with the little damped brush down as per Shure's instructions.   With the brush up, the damping fluid in the tray might have made a slight difference, but really not enough to get excited about in my opinion.   What did make a clear difference, however, was that little brush, stabilizing the arm and improving tracking in all tests.
Sometime later I played with fluid levels in the trough and found that it made no discernible difference until too much fluid was added.  I determined too much fluid to be approximately half full for the Series III trough.  Too much fluid made the sound thicker somehow and noisier.
Second set up, I added a damping trough from KAB to my SL1200GAE, a SoundSmith Hyperion made no audible difference, although using the Ortofon Test Record, it did track a bit better.  I have not experimented with fluid levels on this set up, but left the level below half full.
This experience is not enough to draw broad conclusions from, although I believe Shure demonstrated conclusively that a damped brush on the end of any tonearm can stabilize the arm and aid tracking.  I will go further and opine that this would be so for high and low compliance cantilevers, low to high mass tonearms, and would be particularly efficacious as tonearm length increases.  Again, for emphasis, that is my opinion only and is not based on experimentation.

Bill

Yes Bill, all that makes sense. Basically damping can be useful with cartridge tonearm mismatches or if a particular combination has a very high Q. Using a Kuzma 4 Point (the 11" one) horizontal damping made no audible difference with the Lyra Kleos and Ortofon Windfeld Ti. This is three people listening. Both cartridges have a compliance in and around 14 um/mN and are well matched to this arm. It would have been nice to evaluate this with an oscilloscope but one was not available then. I have one now but my current arm and the ones I lust after do not have nor do they need damping. The Friend with the Zuzma 4 Point lives on the other side of the state so this experiment is not likely to happen in the near future.
Rauliruegas, the Syrinx PU 3 was a top arm in it's day and it still has a big fan base. There are certainly arms today that are better.
I'm sure you love listening to music and perhaps you have wonderful hearing. But what you hear in your own personal evaluations may be interesting but it has ZERO scientific validity. It is only your opinion which I think you have made perfectly clear in spite of the language barrier. 

Oh I guess I should have stated that an "O"scope was used in all my tests.  Really this tool is essential for these kinds of tests to be useful and repeatable.

@mijostyn 

I have tried more than the one arm/cart with the trough including a Moerch DP6 that allows cartridge arm matching - however which way you do it the trough works its magic. It's just i use it with the Helius Omega - a very good arm.

I agree that cartridges do have some in-built damping but it is actually quite crude (it's a piece of rubber). The problem with a rubber spring is the opposite and equal reaction back - ie it's like puncing a ball against a wall. That's why car suspension uses damping whether through air or oil leaving the spring to do its part.

placing the damping at the front where the cartridge is creates a significant mechanical advantage and prevents spurious resonances going down the arm in the first place.

@kps25scTo some extent the trough improves a cheaper arm (i have used a Jelco/Mission arm - it does not take it totally out of the equation.

The Townshend excaliber has come in several guises - many are rega based, but the excaliber sold throughout the 80s was a proprietary design

@rauliruegas 

Funny you like the syrinx - it was re-made by Audio Origami - the chap that makes it is incredibly clever, and will happily speak to you. The current version i am told is a lot better than the Syrinx - i haven't got one so i can't say...

All said the guy from Audio Origami told me that one ought to try different oil weights with the Townshend. The CST/Wt was partially arrived at to stop it dripping - he says a thinner oil works and to try and use the thinnest weight that carries out the resonance control whilst also allowing the treble transients to shine through. I hasten to add that I personally don't think that the silicone weight commonly used robs treble energy - it simply cleans up splash.

I would love to hear a Maplenoll Ariadne as it used a trough, parallel arm and air-bearing.

I think on this note I will try a few different oil weights and try and report back on the thread - silicone oil is readily available for about £3.50 - £5.00 per bottle from radio control car/model shops in precise wt/cst.