Wow, thanks a lot. But I've done something else. I found two RCA connectors also, I have no idea why I ignored them in the beginning, I guess the speaker plugs wandered my mind
I bought RCA to 6.3mm cable and that solves all my problems. But thanks a lot, really. You helped me a lot, if you want, I can still take a picture and post it so you can see what type of connector it is...