As you can see above, even engineers debate this. We have many possible theories, but no actual definitive answers, because no valid testing has (or will) be done. Its completely and costly.
But there are many possibilities:
1. temperature consistency
2. bias consistency, depends on above
3. capacitors "forming"
Among many others. I can watch the bias move around greatly during warm up on prototypes under development, and I can also watch the noise floor fall - for both known and unknown reasons. So*something* is happening, I have my theories.
I'll leave this brief.
G
But there are many possibilities:
1. temperature consistency
2. bias consistency, depends on above
3. capacitors "forming"
Among many others. I can watch the bias move around greatly during warm up on prototypes under development, and I can also watch the noise floor fall - for both known and unknown reasons. So*something* is happening, I have my theories.
I'll leave this brief.
G