SME V arm: dynamic VTF or straight weight

Hi Daniel,
let me get used to this now --- and welcome once again "In der Loewengrube"

>>> A stone-bodied Koetsu <<<
Yes, I hope you'll survive that one. I get your point, and if only for one reason: the other end of that spectrum the DL-103 i.e. a light body with a very low compliance.
This will need some heavy mass arm, end of story.
But now go to the resonance calculation it will confirm this (I bloody well hope so!)
Daniel do us a favour, go check: http://www.resfreq.com/resonancecalculator.html
and let us know if you're findings will be different. And if so - why?

>>> Usually you are better off, if your cartridge is a good "tracker". <<<
Well, right on the money I say --- BUT trackability was the very reason why folks like vdH went to the extreme of 36CU, right? And the Shure V15's (I owned one ages ago) also. Yet again a BUT, the problem I recall was, the EXTREMLY low VTF used in order not to bottom it out in the first place!

Now lets look at some of the low compliance carts. There is not a single ONE, that can claim better than 60µm, yes? Which is a pretty poor showing --- just looking at the maths :-)
Now one more BUT, they also use humongous VTF! 4g and more! If that needle (almost all had a round type, conical stylus then) dropped on the vinyl it made some sizeable pit mark. So it didn't track too badly because it used VTF like a ton of bricks.

So let’s have your take on that resonance-calculator's findings please. And we'll watch out for those lions not get us chewed up over Koetsu and Denon...

Greetings,
Axel

Hi Axel,

the resonance calculator is fine and will work fine AS LONG AS IT DOES NOT DEAL with cartridges of extra heavy weight and/or on tonearms with extra long (10 - 12" ) effective length.

Why?

Because the extra heavy body is on the extreme end of the lever and therefor its add up to effective MOVING mass is very high. To calculate this you need more than just that 3-way calculator - you would need the effective length of the tonearm too and the added mass of the cartridge taken into account in relation to its distance to the pivot/bearing point.

As for the trackability of low compliance cartridges.
Most better samples SPU's and almost all FR-7-series cartridges I have heard (about 4 dozens so far) do easily reach the 70 µm and beyond if aligned and balanced perfectly in a well-matched tonearm. The FR-7-series performs usually around 2.5 to 2.7 grams VTF. EMTs the same. The SPUs do range from anywhere between 2.5 the lowest and up to 5 for some of the older style samples.

VTF alone doesn't tell you any story about trackability. High compliance can not go with high VTF - for obvious reasons. But low compliance doesn't nessecarily needs extra high VTF either.
So your general assumptions on the trackability of low compliance carts is wrong.
However - most if not all high ultra-compliance carts are MMs. They are - viewed as a group - better "trackers" than the MC anyway. But for different reasons than compliance.

So - the calculator mentioned is fine, as long as you deal with moderate weight cartridges in 9" tonearms. When the total length and/or the cartridge mass do increase considerably, it is a different story and the calculation is enhanced by a VERY dynamic factor. Thats why all these calculations fail as soon as you deal with say a Koetsu Onyx or similar.

The crux is the added mass so far away from the bearing point and its immense effect on the effective (NOT static !!) moving mass.

Hope this helps to clarify the point.

Cheers,
Daniel

Thanks Daniel,

now what about that D-103 I mentioned?

Lightweight body 4.8g , Low compliance ~5CU in a 'modern' medium-mass arm?

Axel

Daniel and Raul,
Regarding your advice about damping: I have not used damping on my SME V since I got the Air Tight PC-1. In fact I removed the damping trough and cleaned out any silicone residue. I used the resonance calculator and my cartridge/tonearm combination seems pretty good at 10.5 Hz.

SME V eff. mass = 10-11g
PC-1 weight = 12g
PC-1 compliance = 10cu
Resonance = 10.5 Hz

Settings: no damping, 1.0g antiskate, 2.1g VTF, VTA level with 150g LP, loading at 22ohm with Pass Labs XOno phono amp. Cartridge aligned using MINT Tractor made for specific arm/cartridge combo. Azimuth, zenith and null points all correct.

The PC-1 is a fairly heavy cartridge with low/medium compliance. The math seems to work and it sounds wonderful. Is this because the arm is quite rigid with good internal damping?

Dear Peter, the SME V is VERY rigid and has good energy transmission. The PC-1 is not that heavy and the SME V is a 9" tonearm with fairly loss mass at the end of the lever (the armtube widens towards the bearing - very good to lower effective moving mass and enhance rigidity).

Your settings seems fine to me - especially the antiskating being only 1/2 value of the VTF.

Enjoy your music,
Daniel