I know this thread is many years old, but maybe people can still use this information. I have a CA-150 with a similar issue, but it isn't just when cold and I don't hear static, just silence. I could have a channel drop out at any time, but only at low volumes. Crank it up, and the channel is back. It's been going on for many years, and I had always assumed it meant the tubes in my preamp were near end of life. But now I've replaced the tube preamp with a solid state, and the problem was still there. So I've been using the CA-150 recently with the top off, and when it occurred today, I poked at a few components (with plastic of course) looking for a loose solder joint or whatever, and when I poked the right channel relay, it clicked back on! So, I'm trying to locate new relays, although it may just be a solder/socket issue.
