hello'i found the sound that suit's me but it still sounds crap.since then i have replaced the unbranded speaker with a celestion 10 inch  and it sound ten times better and without  the flabby bass tone and better mids.now the amp is much more to my tone that i was looking for.but thank's for your reply.

Sorry, no suggestion. But why should someone change the speaker of a Code-amp? There are so many possibilities to change the amp's sound by choosing different amp-, poweramp- or cabinet-models, even without all the effects  ... take your time and keep trying, you definitely will find a sound that suits you.