Bass leaves after amp warms up?

I don't live near an airport & wouldn't be affected in that way.

We need Gregory House on this.

What about the Kimber PK10, did you use it with the other amps? I remember someone talking about faulty AC connections, and thought about the plugs on each end of the PK10. Have you ever used the stock power cord?

I set up just analog no digital but w/power conditioner.
Once again I found the sold,dynamic sound.
I said if this stays I will forgo TV,DVD even CD.
But just 20 minutes into listening
I could hear the kick drum less & less
And over about 10 seconds my sound was gone.
When the song was over I had entirely different presentation than previous.
I went back to song #1 & it was crap
In a word anemic sounding
I just heard this song and it was powerful,clear,driving with punch..You name it the sound was the way I like it.
Before I could sit back and enjoy,it was gone.
I'm not making this stuff up..

It's been a while since I used stock power chords but will give it a shot.