daveyf: i have an original model 8 that has been hotrodded by jeff and one of his former tech guys. i've listened to other versions of the 8 in my system. the most discernable difference comes with an addition of the battery or dc power supply. these lower the noise floor dramatically and provide a "blacker" background (at the expense of lowered output). the most current model, 8TiHC, improves upon the PRat and bass control of the original 8 while maintaining the liquidity of the prior models. every upgraded model i've listened to was better sounding in various ways than its predecessor. i'm sorry i can't be more specific but, unfortunately, i did not take notes while listening. how far you go on the upgrade path simply depends, IMO, on how much you wish to spend. -cfb
