Cleeve is correct, check them both out including the tuner. I got a BOSE from MB (recon) and had them install it in the driveway. It still crakled and popped, they sent me to one of their authorized repair facilities, who installed another, still did not sound right. They next repaired the tuner, now sounds "perfect". This was almost a year ago, as you can see my dealer parts guy is a "good guy", they could have stuck me with the amp! You cant beat the offer to check it out for the price of postage, Cleeve is in the "good guys club" in my opinion!