Thank you for viewing. This item is believed to be from the 1970s. It's from the National era of Panasonic. I have only confirmed that it powers on. I have not tested any other sound output. This is being sold as a junk item. - Brand: National Panasonic Solid-state pre-main amplifier that achieves all-stage direct coupling with an OCL circuit. The main amplifier section employs an OCL circuit. This circuit eliminates the capacitors used in the signal circuit, and further, by adopting a dual-power supply system, it also removes the capacitors in the speaker output circuit, resulting in an all-stage direct coupling method, thereby improving sound quality. In addition, a differential amplifier is used in the first stage to improve DC stability and linearity. The preamplifier section uses low-noise PNP silicon transistors throughout, eliminating noise and hum problems. It is equipped with a protection circuit that detects a short circuit in the load and limits the current flowing to the power transistors. It also has an instant recovery type, which returns to normal operation as soon as the short circuit in the load is removed. This circuit has an independent configuration for the left and right channels. It is equipped with a program indicator. It uses a slide control method. The preamplifier section and the main amplifier section can be used separately.