There are very well established Valve users having contributed.
I will post a Copy/Paste of a post I made in a thread recently.
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" I have a System using Valves in Pre and Power Amp's for many years.
I also have other devices with Valves.
I was given advice in my earliest days, to not leave a device using Valves unattended for more than a short period of time.
This is a discipline I have maintained, and to date have not had a incident that would be of a concern, so have been quite fortunate.
I would not be the one responsible for bringing Valves into a Newbies System, this this would have to be the system owners choice.
I would definitely encourage the system owner to learn about Valves pro's/cons prior to making a decision.
My second system is a design to be used to play Music to fill the house with sound and not really need to be sat in front of.
For this reason Valves are not even being considered in the set up. "