like this 3D - why would anyone want a plastic arm is beyond me; and I am only speaking from a engineering perspective, meaning that steel will provide hum isolation to the wires, plastic won't; and both aluminum and steel should be more rigid than plastic?!? Puzzled
Calling it a "plastic arm" sells it short, I think.
I'm lusting for one simply because I anticipate it to be far less colored than a metal arm due to more consistent control of resonances. This is exactly what's being reported by those who've heard it. And, I've yet to hear of anyone reporting an increase in hum when using this arm.
A few quotes from
this review and
this review (italics mine) that point to the engineering advantages of this approach:
"By combining Finite Element Analysis (FEA) with the structural flexibility and internal complexity possible through additive manufacturing, it was possible to create a physical form that
optimized the damping and mechanical behavior of the 'arm to an extent that designers could only previously dream about."
"It’s not just about the shape or vibrational characteristics either: the depth of insight delivered by the FEA along with the range of options possible through additive manufacturing allowed the 'arm to be not just stiffer and better behaved, but its effective mass and weight distribution could also be optimized, while the way the part is grown eliminates any material or manufacturing inconsistencies. T
he sculpted shape combined with a constantly varying wall thickness makes for an 'arm with an impulse response that’s as flat as a barroom pool table"
"The really important aspect of this is that
the manufacturing method allows the creation of a single-piece structure, from cartridge platform to counterweight stub,
that can be optimally shaped and formed to provide a totally even mechanical response. It’s not just a case of being able to produce shapes that can’t be machined; the wall thickness, the internal structure and even crossbracing can be infinitely varied, so that in conjunction with Finite Element Analysis (FEA) modeling,
the resonant character of the piece can be almost infinitely refined."
"By now you’ll have figured out that the 3D armtop is a compelling performer. It’s not inexpensive but frankly I don’t know how else you are going to achieve an upgrade in musical performance that is so big and so fundamentally important, spending that money anywhere else on the equipment in your system."
In other words, this 3D arm just gets the heck out of the way. Who wouldn't want that?