Here's an update on my XiTone/Dayton Audio defective amp saga:
TL;DR
Dayton Audio and Parts Express reviewed my case and have decided favorably on my request for a repair or replacement of the Dayton Audio amp in my XiTone that developed a buzzing problem.
I had originally contacted them to see if I could get a warranty replacement. Unfortunately, they initially denied the request citing that for the warranty to be in effect the request for replacement had to come from the original purchaser, in this case XiTone. Naturally, I was disappointed but I did understand their position. I explained to them that I hadn't gotten any response from XiTone on my request for a warranty replacement. This didn't seem to have changed their minds.
So in order not to have a boat anchor XiTone sitting in my guitar room taking up space, I went ahead and spent $349 for a new Dayton Audio amp from Parts-Express. It arrived in a couple of days and I installed it into my XiTone wedge. (I live about 20 minutes from Dayton Audio and Parts-Express but I had them ship it anyway because I'm too lazy to drive down I-75)
After I installed it, the XiTone was back in action, but now I had the bad amp that while it buzzed terribly it still did work and I didn't want to just trash it. So I emailed Parts-Express/Dayton Audio asking if I could pay to have the defective amp repaired so that I would have a spare in case the new one I bought ever went belly up. Their response was pretty quick when they told me they no longer offer or perform repairs and that they can only replace defective items. I said that I understood, but that I was disappointed because it seemed wasteful to trash the amp if I couldn't get it fixed.
They surprised me by responding asking for more information about the issue. I responded with the facts as I knew them and they had several questions and asked for some proof of purchase and proof of my claim that the amp was defective to which I responded with a copy of my XiTone invoice and a video of the amp buzzing. Several more emails went back and forth over the next several weeks. I'm not sure what went on behind the scenes at Parts-Express and Dayton Audio but after that time passed I received an email from Parts-Express telling me that they were happy to inform me that they would issue an RMA and replace the amp under the warranty if I brought/or shipped it to them so that they could have one of their techs look at it and verify that the amp was defective as I said it was.
This time I got off my lazy butt and went down I-75 to Springboro to Parts-Express with the defective amp and demonstrated the issue to the counter tech. He was able to see that the amp did in fact buzz after warming up and accepted the amp for replacement. He told me that their warranty techs would have to inspect the amp before they could ship me a new one.
After their internal review of the defective amp was complete, they sent me a brand new replacement. Now I have a spare in case the new one I bought decides to die.
I must say that after all of this I'm more than satisfied with the support that I got from Parts-Express and Dayton Audio. They honored a warranty when they really weren't required to and came through for me after that even to the point of telling me what the customizations that XiTone made to the amp's crossover settings were and how to change them. This is an example of going above and beyond for someone that didn't actually purchase their product directly from them. I wish I could say the same for XiTone.
By the way, the XiTone sounds great along side my EV PXM-12MP in stereo!