Sony STR-DA9000ES - Manual (Page 32)

ES Receivers v1.0 Page 32
One-plate/dual-pellet output transistors
How do you combine the power of parallel output transistors with the
"focus" of single-ended transistors? The STR-DA3100ES output transistors
achieve this with a one-plate/dual-pellet design. Each of these is actually a pair
of matched, high-speed transistors mounted to a common plate. In this way
operating temperatures and current fluctuations remain perfectly balanced. It's
another way that Sony fights thermal modulation distortion. As a further
protection, Sony mounts these transistors on oversized extruded aluminum heat
sinks.
With one-plate/dual-pellet output transistors, the temperature and
current fluctuations of one transistor are automatically corrected by the
complementary transistor mounted on the same plate.
Master In-Line Design
With seven channels of amplification, it's difficult to maintain uniformity.
That's why Sony configured the STR-DA3100ES and DA2100ES power
amplifiers with a master in-line design. This achieves uniformity in both electrical
and mechanical characteristics, for superior richness and imaging.
Lined up in a neat row, the output transistors of the STR-DA2100ES
take advantage of Sony's Master In-Line design.