OldJenkins

Yes, I tried connecting it again, but it keeps hissing. Also, if I disconnect the guitar cable from the amplifier there isn't any noise, and if I play music from my cellphone plugged in the amp it sounds perfect. Can't figure out what is it. And if the guitar is disconnected from the amp and I touch the end of the cable it starts making noise.

Hi, Today I got a problem with my Spider Classic 15. I was playing with my cellphone connected to it via jack on the CD-MP3 input. Then a friend tried connecting it to a laptop via the same connector, and the amplifier started hissing heavily. If I touch with my fingers the end of the jack the noise is lower, but its still there. If I do this and at the same time I touch the strings of the guitar it dissapears. If someone is holding the end of the jack while I'm playing it sounds perfect, but I don't know why, and what to do to repair it. Someone has any idea of what happened and what should I do?