6—11
5.3 Block diagram
5.4 Other functions, protections
5.4.1 Short circuit protection
The amplifier contains a protection circuit against wrong / shorted / speaker cable or burnt speakers.
5.4.2 Speaker protection
Protecting the cabinets from harmful direct current.
5.4.3 Overheat protection
Due to insufficient ventilation, ventilator fault or too high environment temperature while playing at high
volume, overheating may occur. In such a case the protection circuit stops the power section until the
temperature of the power stage cools down. This is being displayed by the Mute LED.
5.4.4 Ventilator control
The control of the cooling ventilator is based on the temperature of the power stage’s heat sink. It
automatically switches itself to high speed when the temperature reaches 50 °C and switches itself back to
low speed when temperature decrease below 40 °C. Do not cover the ventilation cutouts!
6 Maintenance, cleaning
The amplifier has no need for particular maintenance.
Occasionally check the starting of the ventilator when you switch on the amplifier!
The preamplifier tube is a long life type, probably you will never have to replace it because of aging.
However, if you feel you are losing sound quality you can easily check it by using the Input 2 on the back.
Replacing tubes must be done by a qualified person. Only replace by using tubes of the same type.
Use only soft and dry or dampened cloth for cleaning. Avoid aggressive, caustic cleaning materials.
Budapest, 2017.08.23.
Tube
preamp
6N2P-EV
Mixer
Speaker
Prot.
Volume
Control
Power
Amp.
Line
Buffer
Fan
Control
Input 1
Input 2
Volume
Gnd Lift
DI Out
Overheat
Sense
Speaker
Outputs
-12dB, Bass, Treble
Aux input
stage
Limiter
