What should I do

You may want to look at a Manley 300b based preamp, which is also a state of the art headphone amplifier, it is one of the world's most remarkable preamps and I think you would find it to outperform the Gamut preamp, and then you can have your cake and eat it to, on some of the headphone forums this combination of preamp/headphone amp and the HD 800's has been lauded as one of the most synergistic and satisfying setups there are PM me for more details.

Mulveling's post really hits the nail on the head and I say this based on experience with equipment mentioned in post(s). I appreciate those who show respect for their neighbors rather than the common me me me behaviors that have become the norm in many places. Thank you for your civility which is becoming something of a rarity in so many areas of western life.

I am an ex-Harbeth owner myself and I would recommend you take a listen to the Grado GS-1000i phones. I basically consider myself a headphone hater and I much prefer listening to speakers in a real space. To me, whatever frequency-based or alleged sonic superiorities of other phones, IMO the Grados sound more like listening to my speakers and less like headphones. At the latest NY show, I listened to many different phones and, except for the Stax, I still preferred the Grados for that reason. Plus,they will sound absolutely wonderful with a Grado battery headphone amp for $350, which is a definite plus. You can always upgrade the headphone amp later if you feel the need.

Get another pair of smaller Harbeths and set up a very near field (speakers 2-3 ft in frt of your chair) listening arrangement for late night. With a bit of practice you will be able to set up and remove in a matter of minutes.

Unless you already listen extensively to headphones, the change from speakers to phones could be unsatisfactory.

While I'm not sure about the smaller Harbeth idea, Rhljazz makes an excellent point about headphones. It seems the people who like them are addicted, but if you're really not much of a headphone listener, don't assume that you're just going to buy a great set of phones and a great amp and problem solved. Many phones, including ones that are allegedly "open", can still sound very constricted if you're used to speakers. Not to belabor the point, but that's what I like so much about the Grados - I really feel like I'm not listening to headphones. Still, I use them far less than I do the speakers.