Koetsu surprise


I have to hand it to my wife.  Like many of us, I have always plotted and schemed my own system upgrades based on my interests and perceived best bang for the buck.  I have been concentrating on the analog front end for the past 4 years and have been listening to a lot more music.  I had been enjoying a Lyra Delos for its detail and upper register energy, a SoundSmith Zephyr Star for its amazing instrumental separation and full frequency balance and an Ortofon MC A90, that I purchased used of Agon.  Thought I was done with cartridges for a long time.
So when on the eve of our 20th wedding anniversary I received a little square box from her, I had no clue that she would gift me something for the stereo.  But there in front of me is a pretty little Koetsu Rosewood Signature Platinum!  
Its hard to describe the disbelief.  I had never considered a Koetsu.  My impression of them was that they were rolled off, romantic, old school cartridges that had been bettered long ago by the likes of Ortofon, Lyra and SoundSmith.  Never really read up on their cartridges given that their cheapest models were about as much as I would ever consider spending.  
Fast forward one month and I have put about 40 hours on the RSP.  From the first needle drop I was very impressed with the midrange presence and the utter ease and extension into the very highest frequencies. The bass did sound a little soft in the first several hours but has tightened up considerably.  It sounded its best loaded with 100 Ohms and mounted on my Mørch DP-6 with heavy brass headshell screws from SoundSmith.  I currently have it on my Jelco 750D with a Jelco Rosewood headshell.  
I don't think any of these arms are the best match but the RSP does sound quite special on all of them.  Just purchased a 40 year old Fidelity Research FR-64S.  Can't wait to listen to the RSP on this arm.  Any recommendations on the FR-64S/RSP combo are welcome.

This whole experience has taught me an interesting lesson about assumptions in our little hobby.  You just have to listen before you judge.  This is a quantum leap in musical enjoyment that would never have happened if left to my own devices. Anyone else have this type of experience?  First time you heard something that changed your mind about what you thought you knew about audio?

I married up!

128x128karl_desch
VTA is very easy. The rest is fiddly - then again, it costs $1k instead of $10k.

I wondered about whether something else, like the torque on the mounting screws, had also changed.  I have my doubts about whether a small improvement in overhang would result in a big change in sound.  Also a change in overhang would make the sound better for certain parts of the record and worse for others rather than provide a uniformly superior sound.

As for the advantages of linear tracking arms, there are MANY theoretical pros and cons.  Some tone arm makers think that most linear tracking arms are actually worse at maintaining perfect tangency.  That is because as the stylus/cantilever move inward the arm resists moving more than would a pivoted arm.  The arm resists moving laterally more than conventional arms because they tend to have high mass in that plane of movement and because of the loss of the mechanical advantage of a pivot (it is easy to move something around a pivot, much harder to move the entire arm laterally along the air bearing tube, even if friction is minimal).  This resistance means that the cantilever is more inclined to being forced out of position (bending inward) with linear arms.  Obviously, the short arms on linear trackers can be made very rigid and less prone to ringing, but, there are arguments as to whether the lack of a conventional pivot prevents vibrational energy from being drained away and dissipated properly.  I don't know if these theoretical claims are true or not; I've heard nice reproduction from linear arms as well as conventional arms and cannot attribute differences to particular design elements.  To me, having noticed how small VTA changes affect sound, I am also concerned that the short arms on most linear trackers would result in larger shifts in VTA for different record thickness than is the case with a longer arm.

There are pivoting arms that take advantage of the "Thales" circle geometry to maintain tangency (also no skating), but, these are expensive, complex, and most require additional arm pivots and parts (added friction).  Some examples are the Thales arm, Schoeder LT, Funk Firm AK-1, and the Reed 5P (the Reed avoids extra pivots that the stylus/cantilever must move by using a motor controlled by a light sensor to pivot the tonearm base to maintain the tangential geometry). 

Quite correct, Larry. I later realized that the effect might be caused by torque. When I get my precision torque driver I'll sort it out.

My posting was ambiguous. I was not adjusting overhang, but offset angle - which, of course, should be 0 for a linear tracker. Overhang is not really the issue with a linear tracker; one is after tangentiality, which can be set very precisely, even for a cartridge like the KRSP, with its invisible stylus.
My newest arm boards have on the fly spindle to pivot adjustment. I have noticed an occasional improvement in sibilance and focus when dialing back and forth.  My guess is that some tonearm manufacturers geometry is possibly just a hair off and the adjustment makes for easy correction. 
Dear @larryi : Till today there is no perfect tonearms. Always exist trade-offs.

I owned some linear tracking tonearms as : Denessen, Southern and ET. I hears many more as Foprsell, Kuzma, the one in Walker Procenium, the one in Rockport and the Transfi, all these not in my system.

I decided to use only pivot tonearm designs because ( even inside its trade-offs. ) makes something no LT design does it and this characteristic is a way better deep bass quality level performance. LT just can't give us the weigth and tigth deep bass as a pivoted ones and maybe can be because are " grounded " mechanically and not float in the air. I can't say why.

Maybe many audiophiles do not cares about deep bass quality levels but it's here where MUSIC starts in a home audio system and the frequency range more critic an important in a room/audio system quality levels. We have to remember here that that bass range gebnerates harmonics and distortions too that affects in sevre way the other frequency range quality levels.

If we have not a real/true full range response in the audio system we just can't enjoy MUSIC and the worst and harder frequency range to handle is precisely the bass range, it's what ( everything the same. ) determines the quality level performance on any room/audio system.

It's easy to check if in our full range system the bass range is rigth or not really rigth and to test this we only need a decent digital source playing same tracks than the analog rig and compare in between and you will know with out doubts..

In any tonearm/cartridge/TT, pivoted or not, ACCURACY in the whole set up is the real name of the game.

A good pivot tonearm design with accurate overall set up has nothing to " envy " to any of those LT designs I named.

Regards and enjoy the MUSIC Not Distortions,
R.