[Stanfoo]

I'm currently using the Fiio E17 & E09K dac/amp combo with the HD598. Would it be worth upgrading to a NFB-15 or NFB-11 if my goal was better sound quality? I'm not sure if the 598 would produce better sound if I did said upgrade.

 

[PurpleAngel]

  I'm currently using the Fiio E17 & E09K dac/amp combo with the HD598. Would it be worth upgrading to a NFB-15 or NFB-11 if my goal was better sound quality? I'm not sure if the 598 would produce better sound if I did said upgrade.

 
You might do better to just replace the HD598s.
For whatever you budgeted for a DAC/amp upgrade and for whatever cash you can get selling off the HD598, put all that money towards new headphones.
 
Would I prefer to have the NFB-15, over the E17/E09K, yes.
(I already have the slightly older NFB-15.32)
 
The NFB-15 WM841 DAC chip is considered a little better then the E17's WM8740 DAC chip.
And the NFB-15 comes with dual WM8741 DAC chips
 
The E09K has a 10-Ohm output impedance,
the NFB-15 has a 2-Ohm output impedance

 

[Stanfoo]

I agree, however I did do that. Got the HD700's yesterday. What I realized was that I got too used to my 598's (I found them way more comfortable than the HD700) so I've decided there will be no further headphone upgrades in my future. My only options are to play around with new dac/amp's if I want better sound.
 
Though the 598's aren't high end headphones so I was wondering if they would bottleneck and not take advantage of higher end dac/amps like the NFB-15.

 

[Mr Rick]

  I agree, however I did do that. Got the HD700's yesterday. What I realized was that I got too used to my 598's (I found them way more comfortable than the HD700) so I've decided there will be no further headphone upgrades in my future. My only options are to play around with new dac/amp's if I want better sound.
 
Though the 598's aren't high end headphones so I was wondering if they would bottleneck and not take advantage of higher end dac/amps like the NFB-15.

You won't find a great deal of improvement in SQ by changing amps or DACs. I suggest you learn to love the HD700s. You have made a major upgrade in purchasing those.

 

[PurpleAngel]

  I agree, however I did do that. Got the HD700's yesterday. What I realized was that I got too used to my 598's (I found them way more comfortable than the HD700) so I've decided there will be no further headphone upgrades in my future. My only options are to play around with new dac/amp's if I want better sound.
 
Though the 598's aren't high end headphones so I was wondering if they would bottleneck and not take advantage of higher end dac/amps like the NFB-15.

 
Technically the NFB-15 has some better specs over the E17/E09K, just not sure if it would make enough of a noticeable (real world) difference, over the E17/E09K, for driving the HD598.
I do not think there is any bottleneck for using a better DAC/amp, with mid range (HD598) headphones.
My bargain priced (way under $100) headphones do sound their best connected to my NFB-15.32

 

[BigJoe]

How would the NFB-15.32 compare to the E10K running DT990 250's? Noticeable improvement, or not much?

 

[davidvanderbilt]

  I'm currently using the Fiio E17 & E09K dac/amp combo with the HD598. Would it be worth upgrading to a NFB-15 or NFB-11 if my goal was better sound quality? I'm not sure if the 598 would produce better sound if I did said upgrade.

 
I don't think there would be that much of an improvement. When I had my HD598s I bought the Schiit Asgard to replace my D4 Mamba (still using ODAC for the DAC) but returned it because there wasn't that much of an improvement in SQ. It wouldn't make any sense to do this, but it would be interesting to see the effect a more expensive dac like a Gungnir would have on the HD598s though just out of pure curiosity. I'm sure there is more valuable info in the HD598 forum. I upgraded to HD600s before I upgraded any other equipment.