[Marcusz]

Hello,
 
I recently bought a B&W P5 headphone with a HRT istreamer.  Very nice sound.  Only one problem.
I have a Pro-Ject headbox MK2 and it appears the B&W is too low impedance for the headbox so i get a some buzz sound when i turn up the volume now.  I bought the headbox for a Grado SR225i but due to extreme listening fatique i traded the SR225i in for a B&W P5.
 
So I need a new headphoneamp now.  Whats is a nice amp that can cope with B&W P5 headphones (26 Ohm impedance).
 
I use it mainly for ipod <-> HRT-istreamer listening.
I don't want to spend too much money on it. so lets say i want to spent about the same amount as i did on the headphone.

 

[Marcusz]

I assume it should be a low power low gain amp due to the high sensitivity of the P5 (120db).
Is Lehmann Rhinelander good enough for this amp (i can get one 2nd hand), or should it be an even lower gain amp?
 
Lehmann has 6db gain.  P5 only needs 50Mw maximum power but i think all amps have more than that.
Is it a problem if the amp has too much power?