SRA Van Den Hul Colibri

[BruceBW]

The problem was always a sagging cantilever, similar to what was shown in tima’s photo, but much worst!

So, I concluded that the horizontal effective mass of the Rockport arm was probably too heavy for the XPP!

The effective mass of the Airline arm is 13g which is within the VDH specified range for my cartridge. This pertains to how it acts vertically. I don't understand how a parameter in the horizontal will cause an arm to be "too heavy" and cause the suspension to sag. Vertically there is close to zero friction. Horizontally it can't move (it can slide L-R but not wiggle more than a few micros due to the rigid nature of the air bearing in that plane) .What am I missing?

 

[thekong]

The effective mass of the Airline arm is 13g which is within the VDH specified range for my cartridge. This pertains to how it acts vertically. I don't understand how a parameter in the horizontal will cause an arm to be "too heavy" and cause the suspension to sag. Vertically there is close to zero friction. Horizontally it can't move (it can slide L-R but not wiggle more than a few micros due to the rigid nature of the air bearing in that plane) .What am I missing?

That 13g effective mass figure of the Airline is probably referred to only the vertical effective mass, and the horizontal effective mass is much much higher! The horizontal effective mass of an airbearing linear tracking arm is the total weight of the whole moving assembly together with the cartridge and the counterweight. Since the moving assembly of the Rockport arm could be pulled out easily, I once measured the weight together with an Ortofon A90 and the appropriate counterweight, and it came to an astonishing 115g or so!