[ceemsc]

... to work their magic on higher impedance headphones?

Case in point, I use a FiiO A5 to feed my Sennheiser HD700 with 150 Ohm impedance.

I usually have the volume pot @ 1/4 the way around to get about ~70 dBr which is comfortable listening volume.

However if I increase the volume pot to about 1/3 the way around, I get ~80 dBr but also the detail retrieval & sound-stage really opens up.

Is this because the louder volume is allowing more detail to be presented which I'm not sure of because I listen in relatively quiet environments or is it because the higher volume allows the amp to feed the headphones more current & voltage to the designed requirements for the headphones to really sing?

 

[PurpleAngel]

We can assume your plugging the FiiO A5 into a computer?

 

[ceemsc]

Actually the audio Chain is :-

Rockboxed iBasso DX50 (COAX Out) -> Chord MOJO (Set at 3V Line out) -> FiiO A5 -> HD700

So the analogue signal should be reaching the A5 @ full line out level.

 

[ProtegeManiac]

... to work their magic on higher impedance headphones?

You're getting it somewhat backwards. Technically speaking, up to a point, chances are anything louder will sound better, because that's how human perception works.

Powerful amps don't "need" more volume. What they are powerful for is that they can go louder and hence go farther to make you enjoy the music (again, up to a point, ie, pain and safety) without distortion, noise, or clipping.

Think of it this way. You don't need a Lamborghini with a V12, but when you take on corners having a very stiff but lightweight, low-slung chassis around a big lump of an engine kicking out 600hp and 500lbs/ft of torque will be a more satisfying trackday.