Bit the Dollar and bought headphones.

Most headfiers that buy the WA22 v1 or v2 end up rolling tubes for the best sound.  That can be said of just about any tube amp but in the case of the WA22 it can cost nearly as much as the amp itself.  The Stellias are very efficient so you won't need much power.  In that price range <$2500, Auris makes a nice tube amp, HA-2SF, that is sold by Moon Audio.  Woo makes less expensive amps like the WA-2 or WA6/6SE that are highly regarded.  Feliks Audio tube headphone amps are a good match with Focals.  A good solid state amp in that price range is the Headamp GSX-Mini.  Burson's TOTL SS amp comes in at about $2500 and it should have enough power to drive just about any headphone that you may buy in the future.  You'll find a lot more information about the amps that you're considering on Head-Fi.

Audio GT R28.  I was looking on Underwood Hifi and came across this headphone amp dac combo.  Anyone have any experience with this amp or others by this constructor?  Smatsui, good point about the cost of rolling tubes.  I would enjoy rolling tubes yet the cost is a big factor.  I’d be looking at new tubes every 6 months or so.  I can’t find any reviews on YouTube for the Rogue amp.  I do not think anyone registered here has the Rogue headphone amp.  That is telling me something too.

Quicksilver and Linear Tube Audio MZ2 with Linear power supply would also be worth looking at. 

Hi,

I'll share my experience with the Audio gd R28:

For years I was happy with my LTA MicroZotl MZ2. It drove pretty much any of the maybe 15-20 headphone I tried over the years.  That was true until I received an email from Adorama regarding a sale, HE16E v2 $609.00.

Well, what the hell I thought. If it turns out I didn't like them I could return them (30 day policy).

Yes, I read all of the forums and reviews that said the HE6 se was so inefficient that you had to have a speaker amp to drive them. Since my MZ2 had driven everything to date I had confidence that it would drive the HE 6's. Not so.

It did reveal, at first, how terrific the HE6 se sounded, the great detail and staging. But as I listened ( I listen mostly to classical) I realized that the MZ2 was running out of steam. 

To make an already long story short, I ended up with the R28 from Wally at Underwood. 

At first I thought I had made a mistake. The sound was veiled & syrupy to me. I had read, & Wally advised me that the R28  needed 500 hours to "burn in". 500 hours!

I am familiar with burn in. My last DAC needed 60 hours, but 500......

If you decide to go with the R28 I will tell you that it need every minute of 500 hours, maybe even 600 hours. Of course the R28 is eminently listenable & very pleasant while the mystery of "burn in" is in process.

My experience is that after 500 hours the R28 is transformed. Detail becomes more distinct. There is more "air" and dimension to the notes. The R28 is capable of very good transparency if you will wait the time to "burn it in". It will also drive ANY headphone with great authority. It is absolutely wonderful on the HE6SE v2, but I can also hear the control and enhanced dynamics on my AKG 812 phones (another hp that benefits from lots of current).

I loved the LTA & Audio Mirror DAC. Wouldn't have even tried another amp/dac except for the HE6 purchase. 

In the end, it has been a bit frustrating, but ultimately, with the phones I currently have, the R28 does a superb job driving them with authority.yet can sound delicate, detailed, and so musical.

For the money, I don't think you can go wrong with the R28.

Just remember; 500 HOURS!!

Whatever headphone amp you’re considering, I’d recommend it have (among other features) a balance control, gain switch and decent power supply. Especially when you’re talking end game.