Amps question

Hi All, I was wondering what you all thought of the old Kalamazoo bass 30 amp I have one that was given to me and it sounds pretty good. I have the choice or luxury of playing through 4 different amps 1 is a peavy rage another is the Kalamazoo I also have an acoustic150 head and an old chinese built amp from the late 60's. They all sound decent but the chinese amp distorts pretty easy but if I hook the acoustic head to the same cabinet it smooths right out. is there a trick to get better sound out of the chinese head? any thoughts are appreciated. Thanks and have a good day.

http://www.amptone.com/

This site seems to have allot of info