Good headphone amplifier

It really depends on what sound characteristics are most important to you and what improvements you’re looking for over what you have now. 

I use an Ifi Ican Pro with my LCD2s. I like it because I can use the solid state mode for better high frequencies, and tube mode for more liquid mids. You can boost the bass and it has a 3D mode (crossfeed?) which I don't use. It is also balanced or single ended. There is one on this site for $1,200.

Thanks for the suggestions. 

If you can find an Auralic Taurus Mk2 amp you would be doing well. I like the Auralic to the point that it was the only original component I kept as a spare to my Moon 430 ha amp.

I have Audeze LCD-XC headphones. I drive them with a couple of DACs, but the one I like the best is my Benchmark DAC1. You can find newer versions of the Benchmark (DAC2, retails for $2K) pre-owned for around $1K. You'll need to look hard to find better, more transparent sound.

Greg, Thank you for your recommendations. I was looking for something in 1k range used. I hope more people will respond with their experiences.

I use a Simaudio 430HA with my LCD-4.  Plenty of power and very detailed and transparent.  I've owned many headphone amps and the 430HA is the best so far.  My Sony TA-ZH1ES is a close second.  What's your budget?

I have owned a number of solid state amps over the years. Including a Vioelectric that I imported from Europe for its high current capability, a Schiit Mojolir and some others. But for me Woo amps sound really natural and have enough power. I ahave the WA6, WA6SE, And WA5LE. While clearly the WA5 is the best it is pretty expensive. The WA6SE has plenty of power and drives them well with a very natural and musical sound. Highly recommended.