I will have to first see if I can get the Titanium HD (or regular Titanium) from my parents or something as a Christmas gift since they live in the States but I currently live in London. Then they can bring it over for Christmas. Otherwise, the Titanium HD goes for £110 here in London which is $170.
Anyway, I always wondered...the Essence ST has 3 amp settings (normal, high and extra high) but if you are using the normal setting which is for headphones with less than 64 ohms, is the amp even turned on or is it just like using a non-amped line out? Meaning, if I did get an external amp and plug it into the headphone jack and use the normal gain setting would I still be double amping?
What is the potential negative impact of double amping?
The Titanium with an Objective2 is the most likely option if I keep the X1's but if I could potentially save money on not purchasing a new sound card then it would be worth it to know about the potential negatives of connecting the amp to the Essence ST headphone jack.
You can have your parents order the refurb Titanium (non-HD) from Newegg for $44.99 or the Titanium HD for $109 (free shipping to them?) and bring it with them on the plane.
Lots of people have used "double amping" and have been fine, but can not say for sure with your setup (just roll the dice).
An external amp can connect to the Essence ST's RCA output for great two channel (stereo) audio.
As the Essence ST uses a true headphone amplifier, the < 64-Ohm setting just means the headphone jack gets less voltage boost and I would guess the best setting for "double amping".
If you sold off the Essence ST and DT990, that would leave you plenty of cash for a headphone amplifier (O2, new $155) and whatever sound card you buy (Titanium HD?).