Sennheiser HD650 Headphone Amp

I have unexpectedly ended up with a HD650, and do not have a single component with a headphone jack, though it sounds surprisingly good direct into an ipod. I would like to find a headphone amp, under $200 used, or possibly an integrated amp or CD player with a good headphone jack. I liked it plugged into s friend's Decco but would prefer not to spend that much.
See if you can find a used Little Dot tube headphone amp.
I have one and it works great with my HD580's.
Bottlehead Crack OTL headphone amp is $219 new. It was designed for high impedance cans like Sennheiser HD650. You'll find plenty of technical info and owner comments in the Bottlehead forum.
I use the HD600 hooked to a Firestone Audio "Cute Series" amp with a matching power supply. Inexpensive and works well. I was unable to drive the 600 with the headphone output of a Mcintosh pream or with an E-Mu USB interface. The 600 needs a little more drive than say a Grado 60, but not a ton. The Firestone amp works fine.
Got 50 or 60$? Got a soldering pencil? Got the DIY bug?

Google 'CMOY Amp' and have a look. Easy to build and depending on the case you choose, portable as well.
I ended up doing a mailorder for a few parts, but much was available at the local radioshack. Better caps? mailorder.

Happy OpAmp rolling!
I used HD580 (same drivers) with Benchmark DAC1. More money but great sound. It can also serve as a preamp or portable unit for travel with laptop.