Should I buy a VDH Colibri or Black Beauty?

Lutenist, The tonearm "effective mass" is a mathematical entity that describes the average of the mass in relation to the square of its distance from the stylus tip. (I am writing this without access to the actual formula, so I may be leaving out some parameter.) In other words, if you put a weight right on top of the headshell, pretty much that weight will add arithmetically to the effective mass. On the other hand, if you put a weight back at the pivot point, the change in effective mass will be reduced by a quantity related to the square of the length of your tonearm from pivot to stylus. Ask the maker of your tonearm for its effective mass spec. Especially for an air bearing tonearm, the effective mass will be very different for the vertical and lateral planes. Mostly, you want to worry about the effective mass in the vertical plane as regards cartridge matching. If I have misspoken here in any important way, please anyone do not hesitate to correct me, but I think this is correct.

I will add my very small head to head comparison in a friends system, (I have MM at the moment) the system is very well set up and extremely transparent, needless to say he has several arms and cartridges, we listened for a long while the XV-1 and it was wonderful, I noticed he had the Colibri in another arm and asked him to play that one...
We played the same Ellis Regina record and it was completely out of this world, we had just played that record on the XV-1 and it seemed like the musicians have moved from the next room into ours! amazing!
Then we played another record we used as a reference in several occasions and that sounds wonderful with the XV-1, it was absolutely horrible with the Colibri, everything was out of place, I cant explain it.

So I would agree with Rudolffzigray, he couldnt have explained it better.

Lewm, here's hoping you have great luck with your Colibri. I agree that my tonearm's effective mass may have contributed to the sibilance but was not the root cause. I tried adjusting everything with it, VTF, VTA, antiskate, damping, loading, you name it. When it was tracking well, it sounded exactly like Rudy and others have described it - amazing, breathtaking, incredible etc. Like Rudy and Jsadurni point out though, I wouldn't want it for my only cartridge as my XV-1s gives me more overall good sound on many more LPs.

Unfortunately, I guess I must NOT be a "connoisseur" as I do not have the ability to mount more than one tonearm on my SME 30. I'd love to have the ability to have say a TW Acustic with three tonearms or, better yet, a Rockport Sirius V. However, with the economy the way it is and my 410(k) now reduced to a 101(k), I'm lucky I don't have a Mattell "Close & Play" (crap, I think I just dated myself)!

Fmpnd, After I posted about VTA, etc, I felt silly, because it is obvious that someone as knowledgable as yourself would know enough to play with all the variables. I guess the only point of contention is that you seem to attribute your dissatisfaction to mistracking, whereas Rudy and I think others say that mistracking did not occur in their rigs, even though their experiences in terms of listening were not far different from yours. I am away from home at a scientific meeting, so I can do nothing for a few more days to test my own sample. But I am anxious to do so, once I solve the problem with fitting it into the Triplanar headshell. It seems I may have a shim that will permit it.

Lewm,

It's hard at times to post on A-Gon and be thorough yet brief or concise enough to keep a reader involved. I should have been more specific and mentioned that the sibilance problem (which both Raul and Rudy have addressed) was separate and distinct from the mistracking that I experienced. Could the mistracking have caused the sibilance? Possibly, but I don't think so as the Colibri is so fast and transients so razor sharp that some sibilance is a probably just a by-product of that characteristic.

My Colibri(s) actually mistracked badly. What shocked me about this was that my Grasshopper and BB were excellent trackers notwithstanding the very low recommended VTF of the van Den Hul designs. I ran the Colbris up and down the VTF scale from .6 gms all the way to 2.6 gms in .02 gm increments all to no avail. I guess it's also possible that the cartridges the distributor sent me were never actually adjusted by VDH or were not actual replacements. Maybe the distributor simply kept sending me the same defective cartridge I originally bought. Either way, I ran out of patience (this took over a year to conclude) and went to the XV-1s and never looked back.