SonoRon wrote:
I was delivered the 400 series hardware with my kit by accident. Now those tom arms had a longer shaft (the hexagonal part) and included a memory lock which the tom sat on perfectly and was far easier. The 600 series is much shorter and like I say no memory lock and its only the bend that stops it sliding down too far.
I recall the different arm designs you mention. There does not seem to be much rhyme or reason for the shift, but if the 400 was a good idea, it's hard to understand why the 600 is better. Or, if the 600 is better, why does the 400 still exist? In addition to the features you've identified, the 600 arm is bent at a 90º angle and the 400 bent at something less, so that when the arm of the 400 series is projecting perpendicularly from the stand, the tom is already leaning at an angle toward the drummer.
The main consequences to the 400 design is that 1.) the tom is lifted higher on its mount and at an angle away from the wing nut of the ball clamp (which may have been thought to permit easier access to the wing nut on the tom prism clamp and vise versa), and 2.) the tom clamping mechanism leaves the tom clamp visually distinct from the ball clamp, cutting down on the visual chatter. Contrariwise, the 600 arm is more elegant, using less moving parts and requiring less persnickety adjustments, and, on its own, looks less as if Reuben Goldberg had been part of the design team. With the 400 Series, it would appear that engineers were working overtime to answer mechanical questions that no one was asking.
I'm unaware that there is any substantive difference in the ball clamp and arm mechanisms. I'll wager that Sonor decided to keep the 400 design in order to differentiate the line from the 600 series, even though it (the 400) was probably more expensive to manufacture.
It doesn't need saying, but the Designer clamp was a magnitude more mature design than either, in function, in beauty, and in sheer mechanical interest, but it was undoubtedly a lot more expensive to produce.