I picked up a Lepai Tripath Class T (from the name Tripath) amplifier and did a load of modifications to it. It has amazing sound now. These can be found on Parts express..
Stock, the amp is quite underpowered for anything below about 100hz. But the following modifications unlock the potential in this little marvel:
1) Replace Power cap (I used a 10K uF 63V)
2) Replace power inductor (I used a 10uH 6A toroidal ferrite core)
3) Replace input Caps (Use 2.2uF audio caps)
4) Remove op amps and bypass tone control circuit
5) Replace output Inductors (I used the same inductor as before)
6) Use a high current power supply - 5A 12V LCD power supply from Amazon.com.
Here is my video description of the mods and a sound sample: