You could just forget amps and soundcards for the moment, buy the D2000 and try it from your DG at the highest gain setting which says it's for >64ohm headphones. You may be surprised how well it drives them as the Denons are not difficult to power.
I just think there's no harm trying it first before spending money. Aedus might be happy with the combo and save some monies.
TBH the differences in running my D7000 out of the STX and the GS Solo are subtle yet the price difference is over £300. It's all diminishing returns with this stuff!
You have a good point.I'll try that then, thanks.
Just 1 other thing: Would my current FiiO E5 benefit the Denon D2000's at all? or would I need an amp on par with the E9 to make a noticeable difference?
Can low-end amps have an adverse effect on the sound quality of the headphones, or will any amp at all have a good effect, no matter how weak/powerful they are?
I have a Shanling PH100 which I use with my D2000s (and other cans), and it's brilliant (about £150 if you can find one). A Little Dot 2 might be worth a punt. Avoid the Project Headbox MK2 - it's a bit pap for the money TBH.
Just a shame aesthetically it looks crapwould rather spend a little more and get something that looks good as well as sounds good. Maybe that's a stupid thing to do, but yeah. With the e7 and the e9 it's acceptable, but just the e9 on it's own looks awful IMO, I'd have to hide it as it would annoy me sitting on my desk.