Hi Scott - I applaud your efforts on the start of a very interesting and relevant project. I thought I'd just bring to the attention of interested readers an AES paper I saw a while ago on this very subject, by Merlin Blencowe of AMS-Neve:
http://www.aes.org/e-lib/browse.cfm?elib=17071
This paper is focused more on the influences of tubes' operating conditions on noise performance, but deals tangentially with some of the stochastic variability of different samples. Also some excellent information on specific noise mechanisms, as well as measurement techniques.
Sorry that (like all AES publications) it's not free, but this is an excellent one on a subject that rarely covered anymore. Thorough bibliography, too.
http://www.aes.org/e-lib/browse.cfm?elib=17071
This paper is focused more on the influences of tubes' operating conditions on noise performance, but deals tangentially with some of the stochastic variability of different samples. Also some excellent information on specific noise mechanisms, as well as measurement techniques.
Sorry that (like all AES publications) it's not free, but this is an excellent one on a subject that rarely covered anymore. Thorough bibliography, too.