I use a JDS Atom amp and a Topping D30 DAC. Total cost about $220
Pretty reasonable as well.
Also, what exactly is going on with the likes of Audioengine and Schiit and such? It's strange to me how these products can have seemingly tons of positive reviews, and yet there is also a vocal minority that speaks out against them. Maybe I'm generalizing too much and I don't want to put words in anyone's mouth, but that's as it appears to me. I'm just curious what the deal is here. (Though to be fair, I haven't seen anyone really talk about Audioengine, whatsoever).
Audiophilia is a huuuuge community, and with any sufficiently large space, you will find contradicting opinions. I recommend not getting excited about that, 99% is just noise. You should find your own reasoning for appreciating things, and get info based on that. in this context, ASR is focused on measurements, empiric evidence, and a general scientific attitude. If these things appeal to you and you consider audio devices as well engineered machines rather than art pieces or expansive jewelry, then this is the place to be. There are good reviews and poor reviews of every brand here, including Shciit and Audioengine, and they are based solely on how their products measure. There is no brand loyalty/hatefulness here.
In that case something with an XLR mic input might be worth considering. Motu has a new affordable M2 but it hasn't been reviewed here yet. My son's a PC/VR/console gamer and nemo inputs.
My advice here is to define preferences and requirements before making a purchase. If sound quality for headphones is the prime factor, going with a device that offers that as a bonus is probably not smart. I have the Focusrite Scarlett 2i2 and it indeed has descent XLR inputs, but horrible headphone output. That's because the main focus in these sound cards is the inputs most of the time, and the headphone out is an afterthought.
. I also ran across one commentator on Amazon who said "Built in 2019 but with 2018 problems. Unfortunately, after numerous negative reports, I do not consider it reliable for the safety of other connected devices".
DX3 pro is known to have QC issues sometimes. There are QC issues with any device, and there are always defective units in any brand. Some devices and companies have higher QC failures than others, and most of the time it's reflected in their prices – lower quality QC, lower prices, roughly (though not always true). Buying from manufacturers like that is not unwise, you just need to know that you incur a greater risk of receiving a defective unit. Decide for yourself if the low price is worth the gamble.
That is to say, the analog pot and dust infiltration aren't concerns or negative aspects? I don't have to worry about the pot gumming up over a 2-3 years of usage from occasional dust getting inside?
Honestly I never heard of dust being a problem with pots. Analog pots can become crackly over time, depending on how they are built, but I don't believe this is a dust issue. I may be wrong though.
The first is the analog pot. Does this mean only mean that the channel balance is a bit out of whack at low volumes, but otherwise it's not seen as a detriment? If digital is superior why would this $400 piece of tech not have digital instead of analog? And how low is low, exactly?
Analog pots and digital pots can both be excellent or terrible, depends on implementation.
For example, here is the channel balance vs volume position of the Aune X7s (analog pot):
Not great. The Element II looks much better in comparison (also analog):
Much better. And here is the same measurement of my own Arcam rHead, also analog pot:
Almost perfect! The difference is, they use different technology.
In contrast, the digital volume control of the DX3 pro looks like this:
Virtually flat. That's basically the difference between analog pot and digital pot. But it's only one feature, and not the end all be all of amplifiers.
Am I correct to assume that any one of those would give me sufficient headroom and such?
Will any of the recommendations of that list that Fluffy shared power my 250 ohm 990s with headroom to spare?
(I've tried to find this "1W or greater output @ ~300ohms" rating but can't seem to find it)
First of all, I need to make an important correction:
Look for ones with ~1W or greater output @ ~300 ohms
This should say "0.1W (or 100mw) or greater @ ~300 ohm". No headphone amp can deliver 1W to a 300 ohm headphone, and they don't need to.
The short way to know if your amp has enough juice to power you headphone with sufficient headroom is to look at the specs.
For the Element II, JDS Labs site shows these specs:
Your headphones are between 150 and 600 ohm, so we would guess the power to be somwere between 165 and 656 mw. Conveniently, Amirm has measured this, and you can see the actual output in this graph:
As you can see, at 300 ohm load (representing headphones of 300 ohm), the Element II can deliver a maximum of 281 mw, at THD+N of about -100db. This is excellent.
If you want to get a bit more technical, the
measured sensitivity of the DT990 is about 99db spl/mw. I'll assume for this calculation that they are also 300 ohm, to make it easier. If these headphones receive 281 mw from the amp, that means they will produce 123.5 db spl. For 250 ohm, it will be even higher. This is the sound pressure level at max volume, and it's beyond deafening. It will probably blow out your eardrums before it blows out the headphone drivers. So in short – yes, it definitely has enough headroom. The same headphone sensitivity with 100mw would give you about 120 db spl (for 300 ohm – higher for 250), so also quite enough.