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

Umbrella - D2D albums - esp Rob McConnell big band

Sheffield Labs - D2D - Harry James, Tower of Power, Thelma Houston

Original Source - new label from DG - classical music re-issues; re-masters from the 1950's, 60's, 70's - incredible sound and performances

BS&T #2 - 45 rpm from Analogue Productions

Steely Dan Aja - 45 rpm from AP

SRV - 45 rpm from AP - any of these - box set - all of them are great

Miles Davis - 45 rpm from AP - from the original Prestige tapes - this is a box set, and all are great

enjoy!

@richardbrand 

I'll have to look to see if I have any Hyperion. Sounds familiar but not sure. Are they D2D or just very well done? Who are the pianists? I have quite a few old recordings of Van Cliburn and V Horowitz.

@dmk_calgary 

Umbrella was a surprise to me. All thrift store finds. Really good recordings and pressings. Have one that I won't really listen to, not my kind of music but I had to admire that it was well recorded "crap". 

Sheffields are really good, have a few. 

Didn't know Original Source but have quite a few DG's. Always good.

Going to have to look for AP stuff. It keeps coming up and I can't think of any that I have.

Pat Metheny From This Place.

@billpete

I would assume the reason for splitting the album up into two vinyl disks with only two or three songs per side would be to avoid using the inner grooves of the record. The sound deteriorates as the circumference becomes smaller. The linear distance in which the information is carved is much greater at the outer grooves than the inner grooves. So it becomes more difficult carve the same amount of information into a smaller linear distance. The higher frequencies begin to suffer as a result. I believe it is known as "inner groove distortion". Someone such as Allan Parsons, an audio engineer himself, would be aware of that. And my guess would be that he chose to avoid that issue by splitting it into two disks. Thus avoiding the inner grooves for fidelity reasons. That would be my guess.