[andybo]

Hello. What is the best PORTABLE Headphone Amp for the Ultrasone Signature Pro ?.  ( For Train..)  There are many..  
 
Thanks 
 
Andy

 

[Huxley]

It's a bit subjective and down to your listening preference.
 
I have the Pro 900's and they pair very well with my P4 Warbler.
 
It provides a clean sound with no distinguishable hiss, bags of power and if the sound isn't to your liking
you can roll the opamps to get it the way you like it.
 
It doesn't get much of a mention nowadays, thanks to the fotm amps
but i certainly feel for the money it punches above it's price.