So what's a bargain-basement DAC that will be an improvement on the E17? The Modi seems to be a possibility, but again, I'm an amp/dac noob of the highest order.
The Modi is definitely an improvement over the E17. Same with the ODAC and I think they're both at the same level. Some think the ODAC is better but I couldn't hear much of difference. This was after days of listening to both. The only difference I heard was better center image depth on the Modi. Huh?! Can't explain that one at all! Maybe that mean't it had a tad less treble.
The E17 DAC has just a tiny touch of warmth and not as bad as everyone says considering it's price and features (COAX and Optical Input!). I often used my E17 for the bedroom attached to the Optical out from the Xbox 360 and my Oppo DVD player. It got the job done and drives my HD-650 and Q701 DECENTLY. The Modi is much clearer and more spacious sounding. Sounds more neutral/natural. The E17's soundstage is much more closed in, but not too bad. There is some very very slight emphasis in the low mids of the E17 it seems. It's a pretty fun DAC overall. Think it uses the WM8740 DAC. I have a Denon 1920 with two of them inside it I got at a thrift store for $6 and love it!
I think the E10 is way worse. I wasn't a fan of that at all and it uses the same chipset I believe. I almost never use the E17 and I just got a replacement in yesterday since it died! As an amp even my outdated Total Airhead is better IMO. I don't have any IEMs though.
For say an HD-650/Q701 the E17 is not something I would ever suggest as a main desktop DAC. Not that it's bad. I can listen to it and enjoy it without any complaints.
So far I went from HRT MSII > ODAC > Modi and then Micro DAC. Each one has been an upgrade, except Modi was a side-grade. I only listen to music a couple hours a day and prefer budget gear under $400. Sorry!
I've found that my Micro DAC is a little bit more revealing of poor recordings and low bitrates and even on the HD-650 it's stupid easy to pick apart all my tracks. This is a little harder on the Modi, but still possible but not as easy. The Modi is very SLIGHTLY forgiving to me. I first experienced that with the T90 I had borrowed. I got that impression with the ODAC too despite what everyone says. The Micro DAC costs me $250 on sale (was originally $350) and the Modi holds up very well.
Even the HD-650 with the Modi was never really laid back. Some extra smoothness in the treble but that's about it. It's a good DAC if you don't want to hear every single subtle recording flaw! Modi is just so clear sounding to me and even on the HD-650. Modi and ODAC sounds great to me with the HD-650. The HRT MSII..not at all to me.
If someone can't afford a $500 DAC there is really nothing wrong with the ODAC or Modi.
Since I'm a HUGE fan of the Modi I could almost guarantee i'd love the Bifrost.
Haha I was reading up on the Valhalla and I bet i'd like that more than the Vali with the HD-650. Skylab's review of it made it seems pretty neutral. It was one of the better reviews i've read.
BTW when I'm reading all your impressions of the Vali a lot of them are similar to what I heard on the modded Q701 with it. It's a crystal clear sounding amp with that thing. With that combo I had ZERO complaints!
I'm surprised there are very few impressions of it with the Q701. The (bass) modded Q701 is VERY close in sound to my HD-650. A little more treble. HD-650 still slightly fuller in the low mids. Bass is actually very similar!
With my modded Q701 the hD-650 gets very little use. I normally would use the HD-650 for gaming/movie due to it having slightly more low-bass. The mod increases low bass on the Q701.
