If the exact same turntable sounded great at the dealers then the problem is not with the records, it's got to be some sort of setup issue. Unless you changed any of the anti-skate, tracking force, etc. since he had it playing you can rule those out too. Look for things that changed when you moved the table.
1) you might be using a preamp with a different mm/mc loading than the one at the dealers - see if it's adjustable to a more precise degree
2) the table might not be as level as it was at the dealers
3) it might be placed on a different surface that at the dealers - actually my first thought. the way the support stand resonates or doesn't resonate is one of the biggest determining factors of vinyl playack. Describe to us how you have your system configured. Some of the "big" mail order places (needle doctor / audio advisor etc..) will have advise and equipment for such isolation.
dont give up...even records with wear can be quite enjoyable. 10% was not an accurate figure :^)
1) you might be using a preamp with a different mm/mc loading than the one at the dealers - see if it's adjustable to a more precise degree
2) the table might not be as level as it was at the dealers
3) it might be placed on a different surface that at the dealers - actually my first thought. the way the support stand resonates or doesn't resonate is one of the biggest determining factors of vinyl playack. Describe to us how you have your system configured. Some of the "big" mail order places (needle doctor / audio advisor etc..) will have advise and equipment for such isolation.
dont give up...even records with wear can be quite enjoyable. 10% was not an accurate figure :^)