Until recently my system required more than 100 tubes to operate and I never had any problems figuring out when something was wrong. Then again, I've used tubes for many years and know what to listen for.
Tubes have a job, just like transistors do. Depending on what you like you can't have "too many" of either.
A good example? Listen to Les Paul or Louis Armstrong where the entire recording from microphone to LP is all tubes, not much to complain about and some of those recordings are half a century old. By comparison some modern stuff is dreadful.
You also ask about variety of tubes in a system. I don't look at it that way, I choose equipment for it's performance and if the tubes chosen can be tweaked by substituting something better (like NOS), I will do so.
I can't do this in an unknown system, but I can hear and remember what each tube does in my system, from input on my amps to rectifiers in my phono. It does take a lot of time and listening but after awhile I can make a cable, footer or phono cartridge change and discuss with others in my group what might be changed (tubes and otherwise) to make it more right.
Tubes have a job, just like transistors do. Depending on what you like you can't have "too many" of either.
A good example? Listen to Les Paul or Louis Armstrong where the entire recording from microphone to LP is all tubes, not much to complain about and some of those recordings are half a century old. By comparison some modern stuff is dreadful.
You also ask about variety of tubes in a system. I don't look at it that way, I choose equipment for it's performance and if the tubes chosen can be tweaked by substituting something better (like NOS), I will do so.
but I have noticed that in the setups with many tubes and/or many tube types it is can be hard to pick out the characteristics of a single tube or tube type. I am not saying that that is good or bad - it just is what it is.
I can't do this in an unknown system, but I can hear and remember what each tube does in my system, from input on my amps to rectifiers in my phono. It does take a lot of time and listening but after awhile I can make a cable, footer or phono cartridge change and discuss with others in my group what might be changed (tubes and otherwise) to make it more right.