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

@flash56 

Just heard Court and Spark, very good. Mine is on Asylum Records and is very well done and nice clean vinyl.

Don't think I have any Japanese pressings of the Who but have the albums. Been awhile for me on those.

Have nothing on Armstrong or Ellington, just not part of my collection. 

Also came across several Pretenders LP's. 

Have a good amount of cello music. Good test music.

Have several Karajan, just came across some last night as I went through part of my collection. 

Cat Stevens, I have most records that he ever made. I have about 6 copies of Tea For The Tillerman, including a 200G remaster, which sucks. Best one I have is on Island. The American versions (/Atlantic, I think?) aren't bad but Island is better. Most of Cat Stevens albums are very dynamic, acoustic guitar, drums and that wonderful voice. All that I have were well done except for the remaster. 

@rauliruegas 

Not sure what you mean about why the Linn, if that is a question or not. Just something I always kind of wanted. Been having issues with various old turntables, VPI needing bearing (off to VAS for repair), most recently was using my old AR (OK not great). Found the Linn at a reasonable price with Ekos arm, Lingo PS, Cirkus bearing. Not sure about any other upgrades. The cartridge sent with it is an old Linn Karma but has been very pleasant listening so far. 

Taking notes on all suggestions. Thanks.

Johnny Hartman. "Easy Living", on Bethlehem stereo.

"Laughing" from "If I Could Only Remember My Name" by David Crosby.

David Lindley's 1981 album El Rayo-X. "Mercury Blues" is a killer track.