The very best sound: Direct to Disc

I own too all the Sheffield's and the M&K too that are outstanding too but not all D2D are that good it depends of the realeased enginnerings down there.

One downside is, once having WOW feeling from D2D records' sound quality, many other records you own sound not so musical to listen to.
I have a few, and always wondering that why other records were not made to the same quality. 

Isn’t it Sheffield lab was now own by Acoustic sounds Chad Kassem?

Chad acquired the assets of The Mastering Lab from Doug Sax, Doug practically willed it to him, it included the mastering lathes and custom tube electronics.

One downside is, once having WOW feeling from D2D records' sound quality, many other records you own sound not so musical to listen to.
I have a few, and always wondering that why other records were not made to the same quality.

D2D requires musicians to play an entire side in one set. Likewise, all the mic and mixing levels have to be set right from the beginning. The results cannot be mixed down to a master, because they are fed straight to the lathe and cut directly onto the wax. This cutting process by the way must also be done in real time. Highly dynamic music calls for greater groove spacing. This requires the engineer to know the musical demands and adjust the lathe all during the cutting process.  

That is an awful lot of things that have to go right in order to cut just one side. The results speak for themselves. But it is very hard to do. Hard usually equates to expensive. So there you go.