Blackbird / SME

I have a Decca Super Gold on my year old Jelco knife edge bearing arm and I hear no indication of this chatter you speak of. If a Decca doesn't induce it, then perhaps it is a well-executed knife edge. Or is that becuase it's not old and worn? Time will tell.

Viridian, Some things are demonstrable facts and others are opinions. I have no problem stating facts for what they are unless someone can give me data to the contrary. Saying that a tonearm "chatters" is a rather derogatory comment sure to bother insecure SME owners. I have never heard a tonearm "chatter." I have never seen a method to test for tonearm "chatter." Until someone shows me repeatable data to the contrary I will hold "chatter" as just anther one of those audiophile myths
this endeavor is ripe with. As for experience. Do you know what being a prison inmate is like? I hope not. You have to have been in that position to understand it, same for being pregnant. Hard to explain to a male what that is like. Experience is the best teacher of all followed by making mistakes.
noromance, great combination. Not even an old and worn knife edge bearing will chatter. To much weight on it. Only if you shake the turntable can you induce chatter. Now a really worn ball bearing race may click if you twist it back and forth. Lets see if I can draw an analogy. A moving stylus causing a tonearm to chatter would be like a fighter plane causing an aircraft carrier to chatter. That should be about right. 

You have to looks for the cartridge dynamic compliance, but not at the compliance measured at 100Hz (like everything from Japanese cartridge manufacturers). You need at compliance figure measured at 10Hz to make correct calculation !!!

I can’t find that information in the manual from Sumiko.
So i have no ideal was it 15 cu @ 100Hz ... or 15 cu @ 10Hz ?

If it was 15 cu @ 100Hz you have to convert it to 10Hz first !
15 cu x 1.7 = 25.5 cu @ 10Hz

25 cu is NOT a low compliance, but a medium-high compliance.

Posters above told you it’s a low compliance, but do they know for sure was it 15cu @ 10 Hz to say so ???

Or it was 15cu @ 100 Hz which makes all your calculation wrong.

To make all the calculation after you will be able to confirm a compliance figure go here on Ortofon website and read this.

And yes, Hi-Fi Test Record is a great tool to measure the actual resonance of your arm/cart combination in realtime.

@viridian As far as I can glean from the Jelco website, it is a "hard metal" knife.
See image