jamato8, not to sound obsequious, is who I look to as the portable amplifier expert here at Head-Fi. His biography is totally understated, to my knowledge he was the thread starter on all Ray Samuels portable amps and probably others going back years. Before I bought the RSA Lightning, RSA Intruder and (just a few weeks ago) the Chord Mojo, I private messaged him first as I trust his opinion far more than most.
Someone posted on this thread whether I had double amped the Mojo with the Intruder to see what it added, if anything. My results from both the RSA Lightning and Intruder were exactly the same as John's in that I felt the sound lost something through the chain. This is in no way to taken as a criticism of Ray Samuels amps as I still believe the Intruder to be one of the best portable amps I have ever listened to.