Changes in DAC Presentation - Need Advice

Well, this is very odd. So, sounds to me like your logic is good. I would add some serious power conditioning. Power is really important. All the great audio components I have had have put a big emphasis on power. A. nmber of them have been two box solutions, with the second dedicated to power.

If you can afford it, I would get an Everest… something that would put an end to the question. If you do power conditioning right the first time, you can forget about it for a long time. I have had my power conditioner for 25 years. Although I now have two direct lines… I tried a Cardas power strip a couple months ago… the test lasted 30 seconds, I went back to my power conditioner. Since the power conditioner effects all the components, it is pretty easy to justify a high level of investment. Additionally, it does not have the level of change of a DAC of streamer from a technology point of view.

From your description, my first guess woukd be breakin. A number of components I have owned have gone through flip flops in sound quality between 100 and 200 hours of use.

The second, and perhaps more likely is your Mac. I assume it is your streamer… PCs are not good streamers. They are noisy sources. There are dozens or more of background processes and other stuff going on. If it continues, I would recommend a good dedicated streamer of comparable or better value.