Abyss ? Luxman 550aii ?

When you buy a pair of what I consider to be one of the best headphones in existence I can only say please don’t drive them with a normal amp no matter how good as the headphone jack on them is always an afterthought. Luxman make a superb range of dedicated headphone amps and I would thoroughly recommend one of them. I have the Luxman P-750u which is one of the best headamps made and although pricey it will outlast you and give many many years of trouble free service. I use mine to drive a pair of Sennheiser HD800 phones and these phones are a notoriously difficult load and my headamp makes it a walk in the park.. I did have the pleasure of having a pair of 1266 Phi for a weekend and they were wonderful to listen to but at the time I couldn’t afford them but I will say that my amp made them sound wonderful. They were dynamic and superbly detailed and I was so sad to hand them back. If you can afford a Luxman amp for them you will I am sure have a supreme setup.

I've owned my 1266TC for about a year and it's one of the best headphones that you can buy.  The TC needs a good amount of power to sound its best.  I've talked to Joe Skubinski, ower of JPS Labs, and he told me that the headphones need about 2 W/Ch or more.  You won't hear what the 1266TC is capable of delivering out of the Luxman integrated from its headphone jack.   

One thing that you could try is to get a headphone extension cable with connections to your speaker binding posts.  Since the Luxman has speaker binding posts for 2 sets of speakers, you can connect your speakers and headphones to the speaker outputs.  Doing this should give you more power than using the headphone jack on the front of the amp.  To do this you'll need to make or buy a headphone extension cable to connect to amp speaker binding posts with either spades or bananas.  On the headphone end of the cable, you'll want either a 4 pin female XLR connector or a female 1/4" (6.3mm) jack.  Check what cable you'll get with the TC.  My TC came stock with a 4 pin male XLR and a 1/4" adapter.  If you try this, be careful when switching from speakers to headphones on your speaker selector switch.  Always have the volume control set to the minimum when switching from speaker to headphones or vice versa.

Most everybody seems to agree the 1266 is great, although I did see a review that measured higher than normal levels of distortion and photos of wrinkled drivers.  That's why I asked about buying used.

I still really don't understand why the 550aii headphone jack wouldn't be a decent source as it uses the exact same circuit that goes to the speaker terminals with the addition of one resistor.  I'd like to know what the wattage output is, it does seem powerful.   The P-750u must be superior with its 3 and 4 pin xlr's and designed for lower power output and I would love to own one but I can't justify as my 550aii is no longer in my main system and currenty only used for headphones.  That's an interesting idea to hook the 1266 to the speaker terminals but as you cautioned I would be afraid I would blow the F... out of the 1266 drivers accidentally.

The seller of the used 1266phi TC is seeming a bit slippery so this aquisition may happen later than sooner but thanks for the input.

@jim204 I also have the Luxman p 750u.

You can see it in my system pics.

Enjoy your system!