Sony STR-DA1000ES Technical Background page 27

Conventional transistors are packaged in plastic with prefabricated
leads (left). To achieve the shortest possible signal path, Sony uses
bare MOS FETs and employs molecular bonding to connect each lead
to the circuit board. The bare transistors and their connections are then
encapsulated for protection.
Even the method of attaching the MOS FETs to the circuit board is
remarkable. Instead of using conventional, packaged transistors, Sony uses
"bare" transistors and molecular bonding. While expensive and time consuming,
this approach makes for the shortest possible signal paths. Sony then protects
the assembly with encapsulation in a protective compound.
Motherboard Topology (STR-DA9000ES)
To shorten the signal paths and optimize the circuit topology, the STR-
DA9000ES uses an internal configuration that's rare in home audio, but common
in computers. The receiver features a large motherboard that forms a "floor" and
provides interconnections to daughterboards that process the signal. Input
signals go directly into an input board, of which one edge is mounted to the back
panel and one edge is mounted to the motherboard. Then the input board signal
flows through the motherboard to the S-Master Pro power amplifier.
Power supply voltage travels a similar route, from the opposite side. In
this way, Sony keeps signal leads to a minimum, protecting the music from the
radiation of spurious hum and noise.
ES Receivers V3.0 Page 27