@nikodavidoff
TA-F808ES uses both S & T type mosfets, so i believe the unit is still in factory state. Do not change unless you have the confirmation that amp was serviced and mosfets were changed. If in doubt check following site: https://audio-heritage.jp/SONY-ESPRIT/amp/ta-f555esj.html
In Japan it was sold under F555ES name.
TA-F808ES uses both S & T type mosfets, so i believe the unit is still in factory state. Do not change unless you have the confirmation that amp was serviced and mosfets were changed. If in doubt check following site: https://audio-heritage.jp/SONY-ESPRIT/amp/ta-f555esj.html
In Japan it was sold under F555ES name.