I wanted to upgrade the fuses in my amp so I ordered 3 Synergistic Red fuses. I think they improve the sound (but it could all be in my head). In any case, about 4 weeks in one of the fuses blew. I didn't think I had any recourse but I contacted Chris at VH Audio anyway. He emailed back almost instantaneously, asked me a few questions and gave me advice on what to do. He then had a replacement sent out. Overall excellent customer service and I highly recommend VH Audio.