Koetsu cartridges - myth or reality?

If I may add to Flg2001's question about the 507. The issue with this tonearm is mostly related to mass distribution once the arm is mounted on the turntable. The arm itself is 3 lbs, which is something to factor in when considering matching it with some lightweight turntables, suspended or not.

A high-mass turntable design, suspended or not, should be able to accommodate the 3 lbs of the arm without much unbalancing of the mass distribution of the turntable. This is because the extra mass added is a small percentage of the total mass of the turntable.

Conversely, if such a weight (3 lbs) is added to a light turntable, the extra mass will be a large percentage of the total weight of the table and this will certainly tax one side of the structure of the turntable, eventually changing its resonance.

Of course, my comments are general in nature and they don't address any specific design of turntable. An engineer designing a light turntable could foresee the installation of a heavier arm and design the mass distribution and structural supports accordingly.

Regards,

iSanchez

Lewm,

The 507 MK II has adjustment for azimuth via the headshell.

VTA adjustment can be done in two ways: one way is by adjusting the mounting hight of the arm, and the other way is via the 'hight adjustment level', located at the base of the tonearm. This level provides the easiest way to adjust the VTA and requires only your fingers. This level moves the tonearm smoothly up and down.

One of the main reasons for me to acquire this arm is that all parameters can be adjusted, and most importantly, they remain that way for a long time.

Regards,

iSanchez

Dgad,

I tried the Hi-Fi News test record about a year ago and I don't recall any anomalies from the test. I eventually didn't expect any weird results from this test since both items are from the same maker.

Lawm, ++++"I am not sure about iSanchez' idea that changing counter-weights has much of an effect on effective mass, especially if the counter-weight is decoupled"++++. Well, it's hard to tell how decoupled the counter-weight is. The documentation states that the flexibility of the mounting stub for the counter-wight is designed to reduce resonances of the arm.

On of the features that I was looking for in a tonearm is that it must be compatible with most cartridges in the market today. I just didn't want to get caught up with a tonearm that couldn't handle a light-weight or a heavy-weight cartridge, should I decide to get one of these in the future.

Dynavector makes the following cartridges:

DV-10X5:   6.6 grams
20x H/L: 8.6 grams
17D3: 5.3 grams
XX2 MK11: 8.9 grams
Te KAITORA RUA: 9.8 grams
XV1-S: 12.6 grams

As you can see, their cartridge weight goes from 6.6 grams to 12.6 grams. According to the specs, optimum cartridge wight for the 507 MK II is from15 to 35 grams, including headshell. The headshell weights 15.4 grams. That means you can use it with a cartridge that weights nothing to one that weights 19.6 grams. This is possible by using one of the three weights supplied with the tonearm. Each weight is optimized for a particular weight range.

Since the headshell is detachable and uses as 4-pin standard connection, the 507 is compatible with any standard headshell in the market today. I can purchase extra headshells, mount a cartridge and forget about it. I can simply swap a cartridge in less than a minute because I only need to make sure that the appropriate weight is attached to the tonearm.

It also helped decide on the 507 the fact that the same company that makes these cartridges also makes a top-notch tonearm. I think one thing they needed to get right is that the 507 worked well with their cartridges.

I don't want to imply that the 507 for sure mates well with Koetsus, but I'll be highly surprised if it doesn't

Below are two links to reviews of the 507 MK II with more technical information about it.

http://www.tnt-audio.com/sorgenti/dynavector507_e.html

http://www.enjoythemusic.com/Magazine/equipment/1205/dynavector507mkii.htm

Regards,

iSanchez

Sirspeedy, thanks for your kind comments. I did find those reviews very instructive when I first read them. I really believe that this tonearm can pretty much handle anything. It is a pleasure to set up and a bigger pleasure to listen to it knowing that it'll extract the most out of the record.

Regards,

iSanchez

Dear Lewm,

Sorry I wasn't more specific about your compliance question. I somehow missed it. The headshell as you point out is on the heavy side. I brought up the different interchangeable weights to show that the effective mass can be increased or lowered just by changing the weight that attaches at the end of the short part of the arm.

Based on Raul's suggestions, I have also tried using lighter headshells, although not as light as the ones he has. I found an increase of speed on the sound with a lighter headshell. This perhaps is the byproduct of having to use a lighter interchangeable weight to match the weight of the lighter headshell and cartridge. I'm not completely sure about why this happens, but a lighter headshell does have a positive effect on the sound.

IMHO, the issue of effective mass is controversial and difficult to measure. How much friction the arm is encountered with as it tries to move will certainly affect its effective mass. Therefore, a light tonearm with high-friction bearings will behave as if it has a higher effective mass.

I haven't found data for the 507 MK II's effective mass, but I found that the horizontal sensitivity is less than 50 mgrams, and the vertical is less than 40 mgrams.

Some people say that a turntable is only as good as its bearing. Well IMHO, the same applies to tonearm design. Of course, not all tonearms have bearings, but whatever mechanism allows them to move should be taken into account.

Regards,

iSanchez

This is a link to a graph you can use to calculate tonearm-cartridge resonance.

http://www.simplyblack.net/Images/pdf/Arm-cartridge_Resonance,_July29,_2007,_B8c.pdf

Dear Dgad, you're right. Playing a resonance test record should yield a more accurate result. I just thought that it would be important to first check with the resonance graph, or something similar, before purchasing a cartridge-tonearm. I personally would not buy a cartridge if I know beforehand that it will have a resonance problem with a particular tonearm.

Regards,

iSanchez