Using Trends PA-10.1D Tube Headphone/Pre Amplifier connect with Two sets of Trends TA-10.2P Class-T Power Amplifier, Trends Bi-amp audio system achieves the sound quality of high-end HiFi but in a very affordable price.
For example:
Trends PA-10.1D SE Tube Headphone/Pre Amplifier x 1
US$299
TA-10.2P SE Class-T Power Amplifier(with 4A Power Adaptor) x 2