Sony STR-DA9000ES - Manual (Page 31)

ES Receivers v1.0 Page 31
quality. At the same time, they're environmentally friendly designs, entirely lead-
free and PVC-free.
Sometimes size does matter, as in the oversized filter capacitors of
Sony's STR-DA3100ES.
Spider Ground Plate
Amplifier designers often assume that the various circuits inside the
chassis all "see" a common ground. Unfortunately, slight differences in
grounding can have a subtle impact on the sound. That's why Sony created a
Spider Grounding Plate for the STR-DA3100ES and DA2100ES. The plate
establishes a "standard reference ground" for all circuits and reduces common
impedance.
Sony's Spider Grounding Plate uses ten points, plus substantially
thicker connections to achieve a standard reference ground.