Cheers Craig. To be honest I'm not sure I will be happy with the bass from the avi's. My pmc's went just low enough for the majority of music but I felt i needed a bit more low end without having to buy a sub to compensate. I realise the TB2's would only give me another 10hz and ideally i would get some FB1's but I'm not sure I can afford them and a decent Bryston amp. I feed my dacmagic with wavs and apple lossless files through the usb connection on the dacmagic. It sounds fine to me but i havent fed the dac from any other source so it's difficult for me to make a comparison however it does sound a bit bright compared to my old cyrus7 cd player though I feel that's more to do with the dacmagic than the quality of the wav/lossless files.
can you use optical instead of usb? i found a slight improvement. might be worth you trying a dem of the dynaudio focus 110 actives, the bass they can do is unreal for their size. they do need a bit of room behind them though, about 50 cm with the passive version was ideal. if you can get a demo of the avi's though i think you should, owners of them seem very happy and you could always add a sub. if you decide against the active route, bryston and pmc always gets great reviews.
i didn't try with the dacmagic, but when i had a cyrus cdxtse and dacx on home dem, my mac was a lot brighter/leaner into the dacx then the cd transport. i know it's a shed load of money and i aren't suggesting you run out and get one, but it might be worth you trying something else into your dacmagic to see if it gets rid of the brightness. maybe you have an old cdp or dvd with opt out? i find mine a bit bright and i now think it comes from the mac.
anyhow, good luck with it.
Mac mini, Chord QBD76, ATC SIA2-150, ATC SCM19
van den hul - the integration, atlas hyper 3.0
atacama rack and stands