Technics SA-C05
The SA-C05 is a 3-piece boombox that was sold by Technics in the 1980's. It was available in both silver and dark gray versions. It has a 7-band EQ with its own on/off button. It provides plenty of power: A minimum of 2x17 watts from 40Hz to 15kHz (at 4 ohms and no more than 5% THD. And 2x20 watts continuous at 1kHz. This is when using 15V DC. It also has a slide-out AC pack.
The service manual can be purchased HERE.