"For two straight nights, the sound is gorgeous with the Morrows. Then the third night things sound bad. This pattern has repeated itself twice now."
I would be careful with regards to that statement. It may just look like a pattern. If you are not listening to your system all the time, there's no way to tell if the problem is occurring at other times, as well. If you lock yourself in to looking for a pattern, you may miss what is really going on.
I agree with the others. Its probably not the cables. I'll list a few things that could possibly be the cause.
-Maybe not all of your other components are not fully warmed up. I've had components that needed to be left on for well over a day in order for them to sound good.
-The time of day/night you are listening. You are much more likely to pick up some type of A/C noise during times with more people are using electricity.
-Your hearing may be temporally "off". If you are exposed to a lot of noise, your system will sound different until your hearing has a chance to adjust. For example, if you've ever came out of a night club, you may have noticed that your car stereo is hard to hear for a little while.
-Your cables may not be well shielded and are picking up noise because of it. That's not a break in issue, though.
-A component that is not in use, but is still in your system, may be causing the problem. That happens all the time and is very easy to overlook. For example, I bought a Sony DVD player to try SACD a few years back. After a few days, I realized that my system wasn't sounding right. I had no idea what the problem and fixed it by accident when I unhooked the Sony. If that's the case, you can fix the problem with a conditioner that isolates or a cable like the JPS Labs digital A/C.
Thats all I can think if for now. If I come up with anything else, I'll post.
