I know this is a Mainline thread, but related to that "chassis" upsetting thought I have both my mainline and crack about a foot away from my pc keyboard and with some tubes like the coke bottle
RCA 6AS7G's when I am typing while listening I can hear my keystrokes as a dull thump sound, if i change to a non coke bottle version built mucm more solid I dont get this sound at all.
No big deal, just be aware of what tubes bring to the table!!
Alex