Koetsu cartridges - myth or reality?

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

iSanchez,

I would chime in and say that your XV-1s has a higher compliance than a Koetsu. I know that Koetsu's are extremely low. The 507 II matches well with a Koetsu. That might make it too high a mass for a XV-1s.

Did you try a test record to check the resonant frequency? That would help answer more questions. You do have some latitude but between 8-12 Hz is ideal.

Dgad, I think the point is that one can alter the effective mass of the DV507 in the vertical plane, by using headshells of different weight mostly. 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, which it may or may not be in the case of the DV507. BTW, the manufacturer's spec for the effective mass of the DV507 is a fairly high 25 gm; that would be with the standard 15-gm headshell, no doubt. The XV-1s is said to have compliance of 10 X 10^6 cm/dyne, while the Urushi is said to have compliance of 10-12 "cu" or compliance units. I think 1 cu = 10^6 cm/dyne. Therefore, the two cartridges have about the same nominal compliance, according to their respective makers. In actual practice, there may be some differences, however, since compliance is frequency dependent and probably VTF dependent as well, and the two companies may have different ways of measuring. In the end, you have to determine for yourself where resonance is occurring in your own system, using a test record, as you say.

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.

My point is that the effective mass of the tonearm is largely governed by the mass between the pivot and the stylus contact point. The CW is on the "other" side of the pivot and I don't think makes much contribution to effective mass. I saw a discussion of this once on Vinyl Asylum between two very knowledgable persons, but I don't recall the final outcome. At the moment I have no time to look up the formula for eff mass, but it's available on the net.