Koetsu Coralstone

garylkoh

WBF Technical Expert (Speakers & Audio Equipment)
Sep 6, 2010
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Can these cartridges be successfully 'refreshed' (whether that means 'retipped' or the suspension parts refreshed)? I only had one 're-do' on a cartridge that was years ago- it was a Van den Hul. It was not as costly as some of these beauties. I would love to have one if it could have a life beyond a couple thousand hours (with the payment of a 'refresh' to keep it going).

Peter Lederman (Soundsmith) does a great job and very reasonably priced. Unfortunately, he does a great job and very reasonably priced - so he is often so back-logged that you might have to wait 6 months or more to get your cartridge back.
 

rockitman

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Sep 20, 2011
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If I have the need to refresh my Koetsu, I will have Koetsu do it. It is no longer a spec Koetsu if you have sound smith or others do the retip.
 

Thf99

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May 1, 2012
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Finally, our Koetsu Coralstone Platinum carts arrived from Japan. Beautiful carts and first impression of the sound is simply heavenly. Coherence from top to bottom is superb.
image.jpg
 

JackD201

WBF Founding Member
Apr 20, 2010
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I own a Jade, love the Coralstones but my heart belongs to the oh so delicate sounding Blue Lace Agate :)

Congrats Thf99!
 

Bruce B

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Apr 25, 2010
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Finally, our Koetsu Coralstone Platinum carts arrived from Japan. Beautiful carts and first impression of the sound is simply heavenly. Coherence from top to bottom is superb.

Wow.... eye candy!! Would love to have one of those!!!
 

MadFloyd

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May 30, 2010
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Is the Koetsu a decent choice for classical music or is too colored?
 

Audiocrack

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Aug 10, 2012
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Is the Koetsu a decent choice for classical music or is too colored?

I almost only listen to classical music. Combined with the Walker and Forsell turntable my Coral stone platinum diamond cartridge is a beautiful sounding cartridge. Although a little bit warmer than the Lyra Olympos the Coral stone platinum diamond is also a very good cartridge if you take the usual hifi parameters into account. So I never experienced it as too colored.
 

MylesBAstor

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Apr 20, 2010
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Nick should chime in about his Azule Blue. That and the Coralstone are reportedly the honeys of the line!
 

rockitman

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Sep 20, 2011
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I'm still running my Coralstone as lead off batter. I can't seem to get motivated to switch it out. My Dynavector XV-1t is still sitting, NIB.
 

JackD201

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Apr 20, 2010
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From what I've experienced going from the wood bodied to the stone platinums is that the woodies have the classic Koetsu sound. Higher in output voltage these are very rich but have their ficus on the midrange. The higher density stone bodies, higher still than even the Urushi laquered woods, along with the platinum motors are more extended in the extremes and tighter as well. If the woodies are colored, the stones are technicolored bot beautifully so.

What I haven't heard at length are the diamond cantilevered Koetsus. My observation is that among the stone bodies the Jade which has the highest MOHs rating among the line that I know of, is the quickest and punchiest. The lightest Blue Lace (Agate) the most delicate and etherial with the highs followed closely (very) by the Tiger Eye andthe Coralstone the most flexible having many attributes of the others. Despite the greater extension of the stone bodies, there are many carts out there that do the highs faster and cleaner and the bass tighter and more tuneful. As far as the mids are concerned there are few that IMO really resemble the Stones or any Koetsu that matter. Among these that I have encountered are the Miyabi and the Shelter Harmony. Surprising to me is the new generation of Lyras which have injected more body into the Lyra house sound. Then again given Stig's long time friendship and relationship with Sugano-san, I shouldn't be surprised.

Koetsu's play all kinds of music well. I think every serious alanog guy should own at least one, if only for the history. Personally I love the vintage sound one can get from Koetsus. When I am in the mood to get a retro vibe with jazz, funk, classic rock and standards I do like to use my Jade even if there are other carts I have that do things just as well but differently.
 

MylesBAstor

Well-Known Member
Apr 20, 2010
11,236
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New York City
From what I've experienced going from the wood bodied to the stone platinums is that the woodies have the classic Koetsu sound. Higher in output voltage these are very rich but have their ficus on the midrange. The higher density stone bodies, higher still than even the Urushi laquered woods, along with the platinum motors are more extended in the extremes and tighter as well. If the woodies are colored, the stones are technicolored bot beautifully so.

What I haven't heard at length are the diamond cantilevered Koetsus. My observation is that among the stone bodies the Jade which has the highest MOHs rating among the line that I know of, is the quickest and punchiest. The lightest Blue Lace (Agate) the most delicate and etherial with the highs followed closely (very) by the Tiger Eye andthe Coralstone the most flexible having many attributes of the others. Despite the greater extension of the stone bodies, there are many carts out there that do the highs faster and cleaner and the bass tighter and more tuneful. As far as the mids are concerned there are few that IMO really resemble the Stones or any Koetsu that matter. Among these that I have encountered are the Miyabi and the Shelter Harmony. Surprising to me is the new generation of Lyras which have injected more body into the Lyra house sound. Then again given Stig's long time friendship and relationship with Sugano-san, I shouldn't be surprised.

Koetsu's play all kinds of music well. I think every serious alanog guy should own at least one, if only for the history. Personally I love the vintage sound one can get from Koetsus. When I am in the mood to get a retro vibe with jazz, funk, classic rock and standards I do like to use my Jade even if there are other carts I have that do things just as well but differently.

Now the *rumor* is that Koetsu has found someone to resurrect an old technology only ever been used by Sony (IIRC?) where not only is the cantilever but the cantilever and stylus are both fashioned from the same piece of Diamond. In other words, the stylus isn't bonded to but actually a part/continuation of the cantilever. Again, this is only something that I heard from the grapevine, albeit a trustworthy grape.
 

rockitman

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Sep 20, 2011
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Now the *rumor* is that Koetsu has found someone to resurrect an old technology only ever been used by Sony (IIRC?) where not only is the cantilever but the cantilever and stylus are both fashioned from the same piece of Diamond. In other words, the stylus isn't bonded to but actually a part/continuation of the cantilever. Again, this is only something that I heard from the grapevine, albeit a trustworthy grape.

I asked someone who did have the diamond cantilever option and he seemed to indicate that the stylus and cantilever are one piece.
 

jadis

Well-Known Member
Apr 28, 2010
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If I have the need to refresh my Koetsu, I will have Koetsu do it. It is no longer a spec Koetsu if you have sound smith or others do the retip.

Same here. That is the essence of owning a Koetsu, imo. It has to go all the way to their production style. When a customer banged his black at the slip of his finger from the headshell handle, the stylus got disengaged from the cantilever. I asked Koetsu how much is the cost of just putting the tip back, or what is referred to as 'retipping'. The reply was they only do rebuilding, (which will set you back $1500-$4000 depending on the model). No such thing as just sticking the stylus back to the cantilever and shipping it back to you. The reason for this is that Koetsu wants their cartridges to perform the way their brand new units do when they get them out of their workplace. The alignment of the entire mechanism has to be as perfect as they know it to be and the process is to strip down any to be repaired Koetsu down, clean everything that has to be cleaned, and they will supply the 'broken' parts so when the customer gets it back, it is almost like new, save probably the body and the magnet. After putting all the parts together, the meticulous process of setting and aligning the cartridge then takes place, if something is wrong, they have to disassemble it once again and realign it till they are satisfied with the performance. That is then when the rebuilt is complete. And Fumihiko Sugano will sign a 'certificate' of the rebuilt plus the date done. Koetsu will even rebuild older models, those with longer bodies (Rosewood and Onyx) whose suspension have worn down, into modern day condition, as 'new'. I have seen Koetsus 'refreshed' by another company, and the cantilever material used, I was told, was Ruby (IINM Koetsu uses boron) and the angle of the cantilever against the base of the body is far steeper than the typical Koetsu.In short, I do not expect it to sound exactly like a Koetsu. For me, the sound of the Koetsu is a total package from Sugano san and company.
 
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jadis

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Apr 28, 2010
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I asked someone who did have the diamond cantilever option and he seemed to indicate that the stylus and cantilever are one piece.

That is quite correct, Christian. I sold 4 stone body Koetsus with the Diamond cantilever option a few years back. I was told that indeed the whole cantilever/stylus assembly was 'carved' from one piece of diamond. There is no joint on these 2 things. And the option, even about 7 years ago, cost $4000 on top of the cartridge price, and is available only for the stone body models. The mantra here is 'Fragile. Do Not Drop', just like those delicate FeDex packages. :D I have a friend who had a freak accident involving his VPI outer ring brushing into his Triplanar arm base while playing and it caused the arm to 'dribble' a bit upon that impact and the result was a chipped diamond, and the stylus part was gone. $4k had to be 'gone' as well. Ouch.
 

jadis

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Apr 28, 2010
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Finally, our Koetsu Coralstone Platinum carts arrived from Japan. Beautiful carts and first impression of the sound is simply heavenly. Coherence from top to bottom is superb.
View attachment 13628

Congratulations, Tan. :) Lovely. Just looking at the 'boxes' makes my heart beat faster again. :D Heavenly, I can believe it. :)
 

jadis

Well-Known Member
Apr 28, 2010
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Is the Koetsu a decent choice for classical music or is too colored?

In my experience, it may be colored, but not too colored. :) I have been playing some piano concertos the last few days with my Rosewood signature, and the piano and strings sound just lovely. If lovely is called colored, then so be it. :)

And btw, in my experience, trying out different loading values can maximize the sound of Koetsus. I was told 100ohms is the best setting, but lately, 40-50ohms sound nice too.
 

jadis

Well-Known Member
Apr 28, 2010
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One of the reasons why Koetsu is supposedly 'colored'. :D

3.2.jpg

Blue Lace, Coralstone, First Generation Onyx (Long Body), Jade, Tiger Eye, and Rosewood Platinum.
 

Thf99

Member Sponsor
May 1, 2012
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Congratulations, Tan. :) Lovely. Just looking at the 'boxes' makes my heart beat faster again. :D Heavenly, I can believe it. :)
Thanks, Phil, especially for your recommendations. The KCPs are real keepers.
 

jadis

Well-Known Member
Apr 28, 2010
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Manila, Philippines
Thanks Mullard. I am suprised that you use such a high tracking weight. In fact I can't find Koetsu's recommended tacking weight in the specs. The 1.9 weight was something A Porter recommended and seems to be in line with the value on Vinyl Engine's Cart database. I will try you settings however once I get more listening experience with it under my belt.

Just saw this post and the previous post to this now. The recommended tracking force is from 1.8g to 2.0g. I track my Rosewood Signature at 1.8g and going 1.9g gives more body to the vocals and cut some edge or harshness at high levels. I still use 1.8g since it works basically fine for all music.

Here's a reference from Chad's page at acousticsounds.com

http://store.acousticsounds.com/pdf/cartridge_comparison.pdf
 

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