Reference site :
http://audio.yoreparo.com/autoestereo/tegno-un-stereo-pioneer-modelo-deh-1550ub-t1175879.html
https://www.drive2.ru/c/965018/
http://monitor.espec.ws/section14/topic52982.html
http://monitor.net.ru/forum/pioneer-deh-1500-info-477172.html
http://monitor.espec.ws/section43/topic223845.html