I sent an email to Command Tech on 5/28 asking about one of their amplifiers and to this day have not heard back from anyone! I also sent an email to QRO the same day and Ray at QRO responded back to me the same night!! He was very friendly and was willing to answer any and all questions I had about his products. You can bet that I'll be giving Ray at QRO a call when I get ready to place an order for my new amplifier.