The PC900 is one of many KUSTOM power amplifier products.
This amplifier has an output of up to 80 watts at 8 Ohm loads even 140 watts at 4 Ohm loads.
But it is not recommended for below 6 Ohm load because the amplifier only uses 1 pair of power transistors.
The following is an edited schematic and a crop of the original schematic.
The preamplifier Q901 & Q902 using transistor number 2N4249.
Voltage Amplifier Stage using the Q903 number 38736. The transistor worked as differential amplifier.
The amplifier also has an Over Current Protection feature by place Q906 & Q907. Q904 & Q905 acting as the driver amplifier, and Finally Q1 & Q2 do as Final Power Amplifier.
36892 is identicaly with NTE130 transistor. That transistor able to produce until 115 Watts of audio output.
Because the Power Transistor only 1 pair, its sugested to loading the amplifier just with 8 Ohm or 6 Ohm load.
Below the suggested number, it will be very risky and cause of hot even damage the power transistor.
