dacs are really big diffrents at all ???

Agree with Chayro. There are huge differences, but since you admittedly don't hear them, then why spend the money?

Admittedly, the type of music you listen to, as well as the file format, will contribute to whether a more expensive DAC pays off. I think that if you listen to Van Halen MP3s while you're vacuuming the rug, one DAC is the same as the next. Nothing wrong with Van Halen, mind you -I just don't think it's the kind of music to judge an audio component with. Unless it's sound reinforcement gear. IMO, you need to be listening to acoustic music recorded at full bandwidth (CD quality at least)with some attempt at fidelity to appreciate the difference between a $500 DAC and something more expensive. Then you may hear the spaces between the notes, the accuracy of timbre of the instruments, the small vocalization sounds, etc. I think this kind of stuff matters to a very small percent of the population - although I would think that anyone owning Leben and Devore would be in that group.

Start with an inexpensive, well reviewed DAC (there are plenty) and A/B test (blind ideally) your way up the ladder until you can't tell a difference.

ok first thanks alot for the response. but still my friends you not convince me (i know you dont try) that there is a diffrent between the dacs.
i tell you what dacs i try and how i do my test (tell me if something wrong pls) :
ARCAM RDAC , ORB JADE2 ,CAMBRIDGE AUDIO AZUR 840C ,TEDDY PARDO DAC .first i must say the ORB DAC was really bad sound broken like sick dac lol. then i test rdac and teddy dac connect them to my leben input and switch between them all the time for 1 hour for few days and me and friends and musicall people that was i invite to my house say we not feel no change no diffrent and i say to them the 1 you hear now is arcam coast 450$ and the seconed is teddy dac coast 1500$ and they all say lol for what people throw they money and i say to my self what the all big deal ??
i like to know my friends what you really think and another thing im listen to good music not mp3 i use flac use foobar so dont let feel stupied that i dont know what i m doing and if there abig diffent i need to hear it and its not matter what im hear its bullshit music is music im hear rock soft rock like dire starits ,sting and more like the corrs and more im not hear a classic music so ???
i m sorry if i was alittle bit decisive but im really like to know what i was wrong ?
and i like to know please what you think about this dacs and what your imperssion and what you think on hegel dac is it better then teddy or better then metrum octave mini nos dac ???

decisive

I think you've proven there are no differences between DACs. Nothing else to say. Over and out.