i have a buddy that asked me about them and i dont have a answer for him..?? mainly he wants a pair of amps they have and wants to make sure serials are intact?? any thoughts?? thanks for any info.. i did search btw and saw good comments but he speciafically wants to know if they remove serials or not.. since he called the manufacture and they will not even fix the amps if there is a problem for a fee without serials so if they go bad after a while and even if he wants to pay to fix them they told him no serial no repair... anyone...??? much appreciated