simon, if you could like things on this board i would like that. i never can stress that enough. if at all possible one must always listen to gear. it does not matter if it is $500 or $500,000. it is a very personal thing. i have seen instances all over the board. very cheap stuff that was great and very expensive that sucked. again, that was just my opinion. someone else may find it the other way around. i feel there is no low or high end or mid-fi. it all depends what you like. i understand their are budgets where people cannot obtain what they do like but that is an entirely different story. regardless i think the 501 and 503 are very solid choices for the money. i like to test inexpensive gear mainly because i can get loaners from being in the industry and i like it to help people. still, it is my opinion. it is not necessarily anyone elses. the most important thing i feel i always say is you must listen. either buy with a 30 day return policy or better yet patronize a local shop. unless they are audio snobs which actually is rare anymore. one point i would like to make is if you can live without dsd. which you should be able to. a r2r nos dac for the same price may very well be better. i can think of some that are.the curve is going to be aweak point on inexpensive gear. even though these have a sort of nos mode. the ayre for instance has an ess but their curve is so refined that it is beating most fpga and r2r dacs. it does not belong mentioned in this thread though because it is $12,000. however a lot of money is going to go into r&d of the curve/filter which is not going to usually be spent on less expensive dacs. still with a few choices the 501 and 503 are very nice. if you need dsd i think you can stop here. however again, that is just my opinion.