Pioneer SX-550 receiver

Pioneer SX-550 stereo receiver. Classic Vintage
 
In 1937 Nozomu Matsumoto created the first magnetoelectric speaker in Japan, and a year later, in Tokyo, he registered the company under the name Fukuin Shokai Denki Seisakusho.
 
In 1961, the company’s name was changed to Pioneer Electronic Corporation. However, the breakthrough came in 1962, when the company entered the Tokyo Stock Exchange and created the world’s first stereo system with speakers in separate housings.
 
Four years later, Pioneer opened branches in the USA and in Europe. In 1978, the company created one of the best-known and most powerful receivers in its history SX-1980. 
 
The SX series are Pioneer’s flagship children from the 1970s. They are characterized by a beautiful warm sound and a high-quality finish. This unit uses a direct coupled OCL system in a power amplifier with the first stage of a differential amplifier. 
 
TECHNICAL INFORMATION:
– power : 2 x 20W at 8 Ohm, stereo
– tuning range FM 88-108 MHz, does not require reprogramming
– bandwidth – 10Hz – 60kHz
– total harmonic distortion: 0.3%
– input sensitivity: 7.5mV (mic), 2.5mV (MM), 150mV (DIN), 150mV (line)
– signal to noise ratio: 70dB (MM), 90dB (line)
–  output: 150mV (line), 30mV (DIN)
– damping factor: 25
–  impedancje: 4 Ohm – 16 Ohm
– dimensions: 45,5m x 15cm x 32cm (W x H x D)
– produced in 1976
– produced in Japan
– weight: 10 kg