Koetsu
- Thread starter jadis
- Start date
Dear Jadis and all other Koetsu fans - please let me clarify some facts about the compliance of a Koetsu and the loooooong and often repeated story of the super heavy tonearms it needs to perform at its best: There are two measurement methods to determine the compliance of a given cartridge. They differ in the frequency were the measurement takes place. One method uses 100Hz, which is the one most of the cartridge manufacturers use today. And then there is an older method, were the measurement is done with 10Hz. So, if we discuss the compliance of a Lyra Atlas or Etna for example, Lyra will measure the compliance at 100Hz, and the outcome is 12cu. Webpages dealing with Koetsu, as also forum threads often claim the compliance of a Koetsu cartridge would be 5cu, which is ultra, ultra low. For comparison, an Ortofon SPU features a compliance of 8cu - and I think we all would agree, that an SPU is a stiff suspended cartridge - or technically more correct - a real low compliance cartridge. If we do a compliance check with a test record such as Ortofon 001 and compare both cartridges (SPU and Koetsu) in the same tonearm, we will get totally different results in a form, that the Koetsu has a waaay higher compliance then the SPU. So it could never be correct, that the Koetsu would have a compliance figure of 5cu, were the Ortofon features 8cu. And here it comes - the 5cu compliance figure was measured with 10Hz - and not 100Hz!!!!! We compare here apples and oranges. If we recalculate the compliance of a modern Koetsu with the 100Hz method - like most of the other companies today use - we will have a compliance of around 10cu (a little bit lower that that). To use such a cartridge, a tonearm with an effective mass of around 12g would be a good starting point.The sweet spot for a desirable resonance frequency would be between 9 and 11Hz. Please keep also in mind, that the mathematically and physically relationship between the effective mass of the arm we use and the resonance frequency is not a linear function. As an example. let's do some calculations: Lets start with a tonearm which features 12g effective mass - and a Koetsu Rosewood Signature, which has a weight of roughly 9,2g. The calculated resonance frequency if we would ad 1g max for cartridge mounting screws, will be 10,6Hz. If I use the Ortofon test record 001, this calculation is proven spot on. To learn a little bit about the effect of adding mass to the system of arm and cartridge, lets do another calculation: In this case we use an arm which features 20g effective mass, the cartridge is still the Rosewood Signature. The outcome with this 20g heavy tonearm would be 9,2Hz. So if we ad 8g of effective mass - which is nearly the weight of the cartridge itself, we will lower the resonance frequency of roughly 1g (a little bit more). Both resonance frequency measurements are totally ok for mass loaded and suspended decks. That tells us, that we can use a 12g as also a 20g arm with no technically issues theoretically. Both resonance frequencies are practically uncritical. Hope that helps a little bit, all the best - EkkiMy Akito 3B is listed as 10g effective mass. So I have to correct myself in saying the ARO was an ultra light mass tonearm.And maybe, the added 3g weight of the Blue Lace over the Urushi can help increase the effective mass.
Hello Ekki, and welcome to the Koetsu thread.
Thank you very much for your in depth and technical explanation of the the compliance issues concerning Koetsus. Indeed your figures help greatly, and to know the conclusion that a 12g - 20g tonearm will work well with Koetsus, is a good thing to know and will lay to rest the early lore that Koetsus need a high mass arm to work well.
Agreed. Having used a variety in that specified range of effective mass, the closer you get to 20g the better it gets!
Don’t know Chop, but in my experience, I have found that very many cartridges sounds better with heavier tonearms, not only Koetsu’s.. My guessing is that the tonearm stands more still and calm, so to speak, and leave the movement in general to the cantilever alone, making the reproduction of the groves more intence… but this is just my thoughts and my findings through my own experiments.. Can’t genaralize it applies to every setup, turntable or tonearm/cartridge but it has certainly worked many times at my place.
/ Jk
(my bold) That's my thinking as well but I'm interested to see if anyone else has a different explanation.
Thanks Johan
My understanding is that Franc Kuzma had written a white paper on this very topic and it can be found on the Kuzma website. No doubt what led to the development of, or was penned after the development of, the Safir tonearm.
Safir has an effective mass of 60g. The local distributor for EMT (and Kuzma for that matter) has informed me that their current EMT carts work perfectly fine (as confirmed by EMT/Mr. Huber) with the Safir and the EMT carts have a higher compliance than the Koetsu's.
The SAT arm is 50g and is a known performer. The Cobra arm on the Caliburn deck is of the same approximate effective mass as the SAT.
The designer of that arm (Cobra) did communicate to myself in a long conversation that the principles/philosophy of high effective mass originated with the Fidelity Research FR64S/FR66S arms and that they simply 'cottoned on' to the idea and some in the industry have since followed.
Safir has an effective mass of 60g. The local distributor for EMT (and Kuzma for that matter) has informed me that their current EMT carts work perfectly fine (as confirmed by EMT/Mr. Huber) with the Safir and the EMT carts have a higher compliance than the Koetsu's.
The SAT arm is 50g and is a known performer. The Cobra arm on the Caliburn deck is of the same approximate effective mass as the SAT.
The designer of that arm (Cobra) did communicate to myself in a long conversation that the principles/philosophy of high effective mass originated with the Fidelity Research FR64S/FR66S arms and that they simply 'cottoned on' to the idea and some in the industry have since followed.
I agree with what Be Quiet said above, that if the tonearm is closer to 20 , the better. But the requisite is that one must have a solid mass turntable to accept high mass tonearm. I can't imagine how a 50-60g EM tonearm will work in an Oracle or Linn Sondek LP12. But if you have a TT than can accept the high mass arms, go for it, no reason to stop there.
As to the question Why does Koetsu seem to sound better in a high mass tonearm, I for one cannot say that because I have not been part of an audio session wherein the goal is to do an A-B-C-D of say 4 tonearms using the same Koetsu (ie Rosewood Signature) wherein one arm is 10g, 15g, 20g or 40g in EM, and using exactly the same TT (ie, an SP 10). Obviously there will be a lot of work to be done in removing and remounting the tonearm from the turntable and installing and uninstalling the Koetsu in the headshell (and doing that cycle 4 times). That would be the only instance when I will be able to say or conclude that a Koetsu sounds better in a high mass arm than a low mass arm.
Regarding EMT cartridges, which were made in Switzerland at Micha Hubers facility, he changed the suspension, when he took over from EMT Germany. The problem with EMT suspensions bevor that change was the durability. As they were made to be used in broadcast station to play 24/7 in the old days, the cartridge stylus was waaay fadster worn out than the suspension was. But as EMT changed their portfolio also toward high end cartridges like the JSD line, they were in need to get something new developed. I had several issues with an old EMT JSD a long time bevor Micha took over. Micha Huber designed a new suspension / rubber damper after a lot of experimentation, which changed the compliance of all EMT cartridges made since then. The old TSD 15 had a compliance of around 15cu - the new JSD series has now around 10cu - which is the same, as the Koetsu features! Regarding question about the sound of heavy mass arms used with the Koetsu compared to lower mass designs: I think we have to observe waaay more than just the mass for the tonearm. Regardless of the housing material of the Koetsu, be it aluminium, stone, rosewood oder Urushi treated rosewood, all Koetsus have in common, that the contact surface between the cartridge and the headshell is directly attached to the motor unit, and made from the same aluminium. The body housing material should have no contact at all towards the headshell system of the tonearm. If we use a headshell which is made from aluminium, we will have the most direct energy transfer into the arm wand. If we use wood, we dampen the energy transfer, if we use different metal materials, we can have an effect between damping, and also reflection of energy. If I change with my Schröder tonearm the headshell plate (it is changeable - and there is a wide variety of materials available) - I do not only change the effective mass, I also change the energy transfer situation between cart and tonearm. If I use aluminium, the Koetsu sounds lively, natural, with amazing micro dynamic shades and also macro dynamic is amazing. The frequency response has the slight upper bass bump, and a little bit recessed treble extension - but other than that - it is as natural as breathing. Now I change the headshell plate and use brass - that ads 5g to the effective mass of the arm - as we all agree, a good thing. But brass does not work at all - the sound becomes over dampened, boring, the microdynamic shades are gone, and the treble energy is recessed! - I had the same effect by using wooden head shells in FR tonearms such as the FR64S as also the SME3012R....WHat I want to say is - good is in the details - so it is soooo damn complicated to exchange experiences - because there is ALWAYS more than one parameter - and some of those parameters are somewhat hidden and not so obvious.
Talking about all the details - maybe it is a good point here, to exchange experiences - not only related to effective mass figures of different tonearms - a lot, and I mean A LOT can be optimised with a correct adjustment: - So here we go:1. The SUT / phono stage
My findings are, that a 1:20 SUT is close to perfection for any Koetsu - which also includes the Urushi Vermilion, which due to its different electric deign has only 0,2mV output voltage - but still 5 Ohm DC resistance. With such a 1:20 step up transformer the cartridge "sees" 117 Ohm, and these 100 Ohm are in my book also close to the optimum, if we use a MC capable phono stage and terminate the cartridge with resistors.
Some people claim, that a Koetsu must be used with 1 Kohm - or fully open with 47 KOhm - and other Koetsu fans claim exactly the opposite - they favour 60 ohm or below. Most of the time the reason for such claims is more related to the geometrical adjustment. The 1 KOhm camp uses this value, because they want to have more treble excitement, the other camp tries to get the bass tighter with a lot of electrical damping (60 Ohms or below).
That bring us to the adjustment process: Here letting alone the correct geometry may it Baerwald, Lofgren or Stephenson (to name a few) - there are other parameters which in my experience can change a lot. First of all, the Koetsu reacts very sensitive to VTA changes. A good starting point would be a parallel adjustment of the top surface of the cart (not the tonearm wand) towards the record surface. As some Koetsu bodies have a slight angle also on the top surface - it is a good idea to use the cart itself - and not the arm wand. From there we have to listen. If we would raise the back of the arm, the Koetsu reacts a little bit different than a Lyra for example. The brass becomes more pronounced as also bloated ans sluggish - and the highest treble is masked by a lot of presence energy, which sits below the highest treble. If we lower the back of the tonearm, the sound becomes waaay more open in the highest registers and at the same time the bass sounds tighter with a tremendous amount of texture and focus. Between good and ok is often a fraction of a millimetre. That means a tonearm with a comfortable and repeatable BTA adjustment is super important in my book.
Then we have the VTF - which is also related to VTA - because if we use 0,5g more tracking force after we set the VTA, the VTA is now slightly off - because the cantilever is now positioned differently. Koetsu gives us a wide range of VTF - the VTF window ranges from 1,8g - 2g - that is the opposite of what Lyra does with their new suspension technology. So we need to experiment. That needs a little bit of time - because if we start with a super nice VTA adjustment and 1.8g - and change the VTF to 2g - the VTA is clearly different....My findings are, that the normal Urushi cartridges (not the Vermillion) can be used to fgreat effect around 1,9g. The Vermillion needs a little bit more VTF, as does the Rosewood Signature and the Black either. With the Black I am always ending up with a little bit under 2g - the Vermillion sounds super nice with 1,95g as does the Rosewood signature - but that may vary with different setups.
A Koetsu does react also very, very sensitive to any kind of needle deflection, may it be caused by a slightly wrong azimuth alignment of too much scatting compensation. So if the treble sounds closed in - and cannot be adjusted by slight variations of the VTA - it might be needle deflection, which causes this. Try to check azimuth again - or / and skating compensation. A good starting point for antiquating adjustment would be the space between the last section of a record - close to the label. You put the cartridge in between the groove - so to speak on blanc vinyl - and adjust in a way, that the cartridge will move towards the label parallel to the "last" groove. This is a slight under compensation - but a good point to start. As skating forces vary always and are related also to the modulation - there is no perfect setup - it will always be a compromise - and therefor less is more! All the very best - Ekki
My findings are, that a 1:20 SUT is close to perfection for any Koetsu - which also includes the Urushi Vermilion, which due to its different electric deign has only 0,2mV output voltage - but still 5 Ohm DC resistance. With such a 1:20 step up transformer the cartridge "sees" 117 Ohm, and these 100 Ohm are in my book also close to the optimum, if we use a MC capable phono stage and terminate the cartridge with resistors.
Some people claim, that a Koetsu must be used with 1 Kohm - or fully open with 47 KOhm - and other Koetsu fans claim exactly the opposite - they favour 60 ohm or below. Most of the time the reason for such claims is more related to the geometrical adjustment. The 1 KOhm camp uses this value, because they want to have more treble excitement, the other camp tries to get the bass tighter with a lot of electrical damping (60 Ohms or below).
That bring us to the adjustment process: Here letting alone the correct geometry may it Baerwald, Lofgren or Stephenson (to name a few) - there are other parameters which in my experience can change a lot. First of all, the Koetsu reacts very sensitive to VTA changes. A good starting point would be a parallel adjustment of the top surface of the cart (not the tonearm wand) towards the record surface. As some Koetsu bodies have a slight angle also on the top surface - it is a good idea to use the cart itself - and not the arm wand. From there we have to listen. If we would raise the back of the arm, the Koetsu reacts a little bit different than a Lyra for example. The brass becomes more pronounced as also bloated ans sluggish - and the highest treble is masked by a lot of presence energy, which sits below the highest treble. If we lower the back of the tonearm, the sound becomes waaay more open in the highest registers and at the same time the bass sounds tighter with a tremendous amount of texture and focus. Between good and ok is often a fraction of a millimetre. That means a tonearm with a comfortable and repeatable BTA adjustment is super important in my book.
Then we have the VTF - which is also related to VTA - because if we use 0,5g more tracking force after we set the VTA, the VTA is now slightly off - because the cantilever is now positioned differently. Koetsu gives us a wide range of VTF - the VTF window ranges from 1,8g - 2g - that is the opposite of what Lyra does with their new suspension technology. So we need to experiment. That needs a little bit of time - because if we start with a super nice VTA adjustment and 1.8g - and change the VTF to 2g - the VTA is clearly different....My findings are, that the normal Urushi cartridges (not the Vermillion) can be used to fgreat effect around 1,9g. The Vermillion needs a little bit more VTF, as does the Rosewood Signature and the Black either. With the Black I am always ending up with a little bit under 2g - the Vermillion sounds super nice with 1,95g as does the Rosewood signature - but that may vary with different setups.
A Koetsu does react also very, very sensitive to any kind of needle deflection, may it be caused by a slightly wrong azimuth alignment of too much scatting compensation. So if the treble sounds closed in - and cannot be adjusted by slight variations of the VTA - it might be needle deflection, which causes this. Try to check azimuth again - or / and skating compensation. A good starting point for antiquating adjustment would be the space between the last section of a record - close to the label. You put the cartridge in between the groove - so to speak on blanc vinyl - and adjust in a way, that the cartridge will move towards the label parallel to the "last" groove. This is a slight under compensation - but a good point to start. As skating forces vary always and are related also to the modulation - there is no perfect setup - it will always be a compromise - and therefor less is more! All the very best - Ekki
...and maybe one more detail regarding an amazing step up transformer: If you are a dedicated Koetsu listener, I would suggest to try out Micha Ulbrichs Consolidated Audio step up transformer. He offers different wire materials such as pure copper, a hybrid between copper and pure silver and silver only. Depending on the coil material you Koetsu uses, the outcome may differ. I liked the hybrid step up device a lot with the silver cladded coils of my Urusi cartridges as also the double coil structure of the Vermillion - pure silver will give you maybe a little bit more treble resolution - so this might also be a variant worth to be tested! The pure copper version sounds amazing with the Black as also the Rosewood Standard and Signature, as they have pure copper coils. The next best thing in my book was the Cotter L with the 3mV stone bodies, the Rosewood Signature Platinum as also the Vermillion.The Cotter PP in 1:20 configuration works fine with the rest of the portfolio (0,4mV). Unmolested Cotter step up transformers are super rare today - so the Ulbrich in comparison performs very clearly better, and is available here and now! All the best - Ekki
Fully agree on your recommendation for the Consolidated Audio step ups!
my current personal reference for the Koetsu carts, specially the stone bodies , is the Phasemation T-2000 step up,
which plays in my current set up above the Consolidated Audio Step ups.
Unfortunately T-2000 sells for a significant higher price.
Blue Lace. I have an Onyx Diamond and a few others also.
If you send them to me Travis, I’ll buy you a coffee… !!!
!!!
The owner of this Blue Tiger Eye told me that when seen under sunlight, it is bluish. These pictures were taken under a yellow light bulb.
Similar threads
 | Steve Williams Site Founder | Site Owner | Administrator |  | Ron Resnick Site Owner | Administrator |  | Julian (The Fixer) Website Build | Marketing Managersing |