The differance between MFSL Ultradisc I and II?

I believe the two version used their GAIN recording method.

Thanks for the responce Qdrone!

However, how can you tell from the ouside of the box if it is an Ultradisc I or II?

The CD longbox (Remember those)that I have just says Ultradisc on the front.

The I's are more rare than the II's. I prefer the I's over the II's for better sound. The difference is that of being pressed in the US (I's) verses that of being pressed in Japan (II's). The first versions were also aluminum verses that of gold..........

I have the first pressing Track Record/MCA vinyl Quadrophenia purchased on the day the album was released in the U.S., as well as the Mofi CD. The vinyl sounds much better than the Mofi CD, apart from the glow of nostalgia of bonging through all four sides twice in a row listening to Advent speakers in my freshman dorm in the fall of '73.

I bought a few of the early Mofi Ultradisks and could not hear a wit of difference between them and standard issue CDs. I believe the GAIN System/UD IIs were mastered on Mofi equipment upgraded with Theta technology. To my ear these are a step up from the original UDs, tho perhaps no better now than subsequent reissues by the record companies.

Dave