Birwynne
As one who had the Ref110 for a few years in 6550 form and then in KT120 form and then the Ref 150 since its initial launch, my opinion is that the 110 was a very good amp but a little too diaphanous--not very strong in the midbass and lacking a bit in "flesh on the bones" imaging. The Ref 150 is a significant and important upgrade in many respects. But most of all, it banishes the above weaknesses of the 110. The difference is more than a matter of degree. The Ref 150 is a great amp and I believe will go down as a classic in the ARC line. The Ref 250 gives a little better grip on the bottom and slightly better dimensionality, but the differences between the 150 and 110 are much greater than the differences between the 150 and 250. A trade up from the VS-115 is an easy call and one that you would never regret.
As one who had the Ref110 for a few years in 6550 form and then in KT120 form and then the Ref 150 since its initial launch, my opinion is that the 110 was a very good amp but a little too diaphanous--not very strong in the midbass and lacking a bit in "flesh on the bones" imaging. The Ref 150 is a significant and important upgrade in many respects. But most of all, it banishes the above weaknesses of the 110. The difference is more than a matter of degree. The Ref 150 is a great amp and I believe will go down as a classic in the ARC line. The Ref 250 gives a little better grip on the bottom and slightly better dimensionality, but the differences between the 150 and 110 are much greater than the differences between the 150 and 250. A trade up from the VS-115 is an easy call and one that you would never regret.