Hi, totally new to Line 6 here so please excuse my ignorance. My brother in law passed away and left me his dt25 and hd500x. I tried to get sound out if just the amp to no avail do I checked the speaker fuse, speaker, tubes and even bypassed the preamp but can't get anything out of the amp. Does the hd500x need to be hooked up to the amp via the link for it to work? Also I don't have a midi interface so can I go through the he to update the amp? Thanks in advance for your help!