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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

Showing 6 responses by larryi

larryi
3,742 posts
 
My local dealer is a BIG Koetsu fan, particularly the wood and lacquer bodied versions.  He likes the top end Ortofon arms.  These are the arms with the square pivot assembly (e.g., AS-309S 12") that is available from Japan, but not commonly available in the US.
 
larryi
3,742 posts
 

The entire Koetsu line has a saturated, harmonically dense sound that is quite musical sounding.  If you want it slightly leaner and a little more like other top end cartridges, then the stone bodies Koetsu would do the trick.  The wood and lacquer cartridges are a little warmer sounding.  If there is any shortcoming with their line, it would be that they don't track quite so well with some of those freak records designed to torture test cartridges; but with regular music, they track perfectly.

There are not that many other cartridges that have the same sort of warm and relaxed sound that also manage to avoid sounding muffled or soggy.  Allaerte, comes to mind, but, some of those make Koetsu cartridges seem bargain priced.  Perhaps the Ortofon SPU models, but, they require arms designed for the integrated headshell.

larryi
3,742 posts
 
Karl,

Have you considered the Moerch DP-8?  I think that it is at least an interesting design.  The arm has weights on outriggers located right at the vertical pivot of the arm.  The weights substantially increase the horizontal effective mass of the arm, but, because they are located around the vertical pivot, they don't increase the vertical effective mass substantially.  What this is designed to do is to use the higher horizontal movement effective mass to resist movement of the arm from side to side in response to horizontal modulation of the groove. Very low bass is typically mastered in mono so that the groove motion is primarily side to side (if mastered as a stereo signal, the vertical depth change would be too much for the thickness of the record).  By the arm not moving in response to the bass modulation, the full measure of the bass is outputted by the cartridge.  By keeping the vertical effective mass reasonably low, the arm can still effectively handle warps. 

I have not heard the DP-8, but, those who have say the bass response is very strong with this arm.  It should be particularly effective with somewhat low compliance cartridges, like Koetsus.

While this purely speculation on my part, high effective horizontal mass of air bearing non-pivoting arms might also account for why they too have strong bass response.  I heard this with arms like the Mapenoll, Walker and Kuzma arms.
larryi
3,742 posts
 

Wow, Terry, that is a really interesting sounding DIY table.  The platter is about 100 lbs!  With that kind of weight, an air or magnetic bearing is the way to go.  NICE!!

By the way, the material for your cantilever does not have much bearing on the compliance of the cartridge.  The amount of force needed to deflect the stylus to a specified distance (compliance) is really determined by the cartridge suspension.   

Mulveling, it must be great having three different Koetsu cartridges, including the top stone cartridge.  Do you have any other cartridges?  I have sometimes been tempted to get something radically different just to mix things up.  Have you been tempted to get something like a Colibri, just for something completely different?  (I like spending your money for you).

larryi
3,742 posts
 
All Koetsu owners,

By implication from the post above, you should all throw your cartridges in the trash because they are high in distortion.  I don't know if that really is the case, and even if this were an objective fact, clearly, this supposed distortion doesn't matter much.  If it did, one can do even more to avoid it by avoiding analogue altogether and by buying a cheap CD player instead--by objective measurement, even a cheap player is vastly superior.
larryi
3,742 posts
 

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). 

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