What are your go to LP's for evaluating new gear or new tubes?

To @billpete, good for you. I like AR9s quite a bit and their history.  As you may be well aware, known as the "inspiration of future audio products" in its era. While I’ve never owned a set myself, a local dealer had a set a few months back to admire. I suspect with the right amplifier(s) handling them and those two parallel-wired 4-ohm woofers, i.e. the "electronic automatic transmission" as I recall, can sound really cool.

Not to sidetrack too much, yet Audioholics did an updated editorial review in 2023 on your AR9s. Just have to love all the speakers made back when. I enjoyed seeing them back then, not too often though. Not sure if you saw this before but thought i’d mention it - https://www.audioholics.com/editorials/acoustic-research-ar9

"@billpete I do see some die hard old vinyl guys like me, switching to streaming nowadays."...

You can do both. Experiencing remastered content, and how learning engines of streaming works, and discovering more of the types of music you enjoy now, opens so many more doors of listening enjoyment.

Ask those same diehards if they quit streaming and went back to vinyl & CDs only. I’d venture to guess it’s a small percentage - if any. Quality streaming can be a game changer for those who try it and embrace it fully. Enjoy.