ETI Amplifier Repairs

ETI 300 Watt Amplifier

ETI 300 Watt Amplifier ETI 300 Watt Amplifier

I decided to try my luck with an old ETI amplifier design from around 1980, 300W into 4ohms. I drew the PCB layout freehand, wish the Dalo Resist pens were still available as the ones available now are rubbish. Anyway didn't turn out too bad, had problems with powering up after assembling the parts etc, always make sure resistors are soldered in even if they look as though they are! I had to make some changes to resistor values with the components I used in the temp sense area but powered up OK eventually.

ETI 100 Watt Powertran Kit

ETI 100W Powertran Kit

This would blow the positive fuse at switch on. The transistors checked out okay. It turned out to be the 100 µF 3 V tantalum in the feedback to 0V was short circuit.