Sony STR-DA1000ES - Manual (Page 26)

ES Receivers V3.0 Page 26
MOS FET output transistors (STR-DA9000ES)
To achieve 200 watts x7 (20—20,000 Hz, 8 ohms, 0.15% THD), the STR-
DA9000ES incorporates some unique power amplifier technology. For example,
the power amplifier uses Metal Oxide Semiconductor Field Effect Transistors
(MOS FETs), highly prized for their linearity. Four MOS FETs per channel are
configured in modules that are direct-mounted to heat sinks in a "circuit-on-
chassis" configuration.
The STR-DA9000ES power amp circuit board features seven heat sinks
for the seven output channels.
The output stage is attached to the underside of each heat sink in a
"circuit-on-chassis" configuration. The black capsules in this picture
protect and insulate the four MOS FETs.