Pioneer AM/FM stereo receiver model SX-3900. From 1980 - 1981. The SX-3900 offered subtle improvements in its specifications over the SX-3800, additional controls, and boasted 120 watts per channel. The larger output transformers increased weight to 44 pounds. Sold for $800 back then. Features, tape one and two in/outputs, two phono inputs, one aux input, digital display bright/dim, filters. This was the beginning of the digital age. Notice the tuner also features a digital readout along with the analog tuner, Also power meters are digital. One of the last receivers before pioneer did away with the analog tuner.