- Capacitors except C10 & C9 are ceramic.
- Capacitors Electrolic must be rated 50V.
- Use a well regulated and filtered +/- 12 V dual power supply that is able to provide at least 2 A continuous current.
delivered into an 8 Wload with a symmetrical power supply of ±16 V. The gain is internally fixed at 30 dB, thus offering a low gain spread and a very good gain balance between the two amplifiers (0.2 dB). A special feature is the input mute circuit. This circuit disconnects the non-inverting inputs when the supply voltage drops below ±6 V, while the amplifier still retains its DC operating adjustment. The circuit features suppression of unwanted signals at the inputs, during switch-on and switch-off. The mute circuit can also be activated via pin 2. When a current of 300 mA is present at pin 2, the circuit is in the mute condition. The device is provided with two thermal protection circuits. One circuit measures the average temperature of the crystal and the other measures the momentary temperature of the power transistors. These control circuits attack at temperatures in excess of +150 °C, so a crystal operating temperature of max. +150 °C can be used without extra distortion.