First of all I am so excited to hear that you are still enjoying the Dinas…and your friend. Funny story, I remember when you shared those photos of your walnut build. Still one of my favorites. I am a sucker for black walnut. Now for the bad news.
You almost certainly damaged the amplifier on the Dinas, and I am surprised you didn’t damage the other amplifier as well. The easiest way to test this is to hook each of the drivers from the Dinas to another amplifier (use the same source you were previously trying). If they are working fine, then it is the Lepai amp that blew. If they are not, then we need to investigate further.
When you test the drivers, test them at low volume. They do not have to be loud, and you definitely don’t want to damage any of the drivers.
Finally, I must say, you are a good friend. My dad still wants my pair of Dinas. He hasn’t got them yet 🙂