[SirMarc]

I've also been considering upgrading my Fiio E10K to get the most out of my 598s.  To me, the Fiio sounds a little bright and is lacking some bass quantity and quality.  I know the 598s don't require much power, but I know an amp can improve sound quality noticeably, regardless.  I think I'd prefer a small, usb-powered, DAC/AMP combo.  I've been reading a bit about the Dragonfly, the Audioengine D3, and the Apogee Groove.  Many describe the D3 as having a warm, punchy, analog sound which I like, but with the 598 already being on the warm side of neutral, not sure it would be a good pairing.  Anyone have experience with any of these 3 and the 598s?  Any others I should consider that are a good match with the 598s?  Again, requirements are small (no bigger than E10K) form factor and powered by USB.  $300 is the absolute limit of my budget right now.  Thanks.

I've been hearing very good things about the dragonfly 1.2

 

[paulguru]

 
Not quite.  According to Sennheiser, supposedly identical products except for color, but yes, my 2 pairs sounded quite different.  Others here have also mentioned their 2 Ivory and SE pairs sounding different.  I think the differences I heard between my Ivory and SE are due to some unintended variations in manufacturing.  Yes, SE is the black one.

Ok but compared to 400S the bass of 598 is deeper ?

 

[Hammy]

  N22 is a stereo amp I think, not a headphone amp.

 
Fact check before giving bad information.
 

  I've also been considering upgrading my Fiio E10K to get the most out of my 598s.  To me, the Fiio sounds a little bright and is lacking some bass quantity and quality.  I know the 598s don't require much power, but I know an amp can improve sound quality noticeably, regardless.  I think I'd prefer a small, usb-powered, DAC/AMP combo.  I've been reading a bit about the Dragonfly, the Audioengine D3, and the Apogee Groove.  Many describe the D3 as having a warm, punchy, analog sound which I like, but with the 598 already being on the warm side of neutral, not sure it would be a good pairing.  Anyone have experience with any of these 3 and the 598s?  Any others I should consider that are a good match with the 598s?  Again, requirements are small (no bigger than E10K) form factor and powered by USB.  $300 is the absolute limit of my budget right now.  Thanks.

 
IIRC the E10K is considered on the warmer side of neutral, interesting you find it a little bright with these.  I have to say that I did prefer the bass boost switch when using it with the 598.  I don't know how well these scale, but I'm really interested to see what other suggestions you get.
 
For those who want to emulate the E10K bass boost feature, check this post.

 

[trung224]

Owned the 598 for more than 1 years, I can say that it scales upto with 200 USD amplifier/DAC. I don't think it's scaling stopped at Fiio E10k or E17. The 598s need something like Magni/Modi combo, iDSD nano, Geek Out 450, ODAC/O2 to show up its full strength. 

 

[VeggiePopper]

Owned the 598 for more than 1 years, I can say that it scales upto with 200 USD amplifier/DAC. I don't think it's scaling stopped at Fiio E10k or E17. The 598s need something like Magni/Modi combo, iDSD nano, Geek Out 450, ODAC/O2 to show up its full strength. 

Have you triedy yourself the iDSD nano paired with the HD598?

 

[trung224]

Yes, I owned both HD598 and iDSD nano at certain time. Moving from Fiio E17 to iDSD nano was an real improvement for me. Both of them (Fiio E17 and iDSD Nano) are warm DAC/Amps but in term of details and dynamics, the iDSD nano is far ahead. The Fiio E17 sound very muddy and congested.
  The Schiit stack is better than the iDSD nano in term of dynamics and bass resolution (so objectively they are the better combo)  but I found them too bright for the 598s, which is a bright headphone itself.

 

[LazyListener]

  Ok but compared to 400S the bass of 598 is deeper ?

I don't know about deeper, but there's definitely more audible bass on the 598.  I read that the HE400S rolls off very steeply in the bass frequencies with the stock pads.  I used EqualizerAPO software to EQ more bass and they responded very well to that.

 

[LazyListener]

  Owned the 598 for more than 1 years, I can say that it scales upto with 200 USD amplifier/DAC. I don't think it's scaling stopped at Fiio E10k or E17. The 598s need something like Magni/Modi combo, iDSD nano, Geek Out 450, ODAC/O2 to show up its full strength. 

Are any of those solely USB powered?  I know Magni/Modi and ODAC/O2 are not.  I'm looking for USB powered only.  Battery powered would be fine, too, as long as if the battery eventually dies, I can still power it over USB.

 

[LazyListener]

   
Fact check before giving bad information.
 
 
IIRC the E10K is considered on the warmer side of neutral, interesting you find it a little bright with these.  I have to say that I did prefer the bass boost switch when using it with the 598.  I don't know how well these scale, but I'm really interested to see what other suggestions you get.
 
For those who want to emulate the E10K bass boost feature, check this post.

Hmmm.  Interesting.  I've read several reviews that said the E10K is more neutral or slightly bright sounding.  That's definitely how I hear it.  Compared with my iPhone 6, the iPhone sounds warmer, with a bit more bass and smoother mids/highs  Now, the E07K I saw described as warm.  I've found I also prefer the bass boost on for most songs.

 

[trung224]

 
Are any of those solely USB powered?  I know Magni/Modi and ODAC/O2 are not.  I'm looking for USB powered only.  Battery powered would be fine, too, as long as if the battery eventually dies, I can still power it over USB.

Geek Out 450 is USB powered only. And iDSD nano has both battery powered and USB powered. Geek Out 450 is discontinued now but you can see many of them on sale in For Sale/Trade forums in the last few months (because of the release of Geek Out v2)

 

[LazyListener]

 
Here are some EQ files based on this chart (thanks fallrsk!).  Disclaimer being that it took me 5 minutes to make these, I used a lot of guesswork and estimation, and I have no clue what I'm doing.  The foobar2000 one is for use with the Graphic Equalizer plugin, and the Equalizer APO works system-wide.
 
foobar2000: https://drive.google.com/file/d/0B3fhrQO4W3Xea2JjTVRRV2o2V28/view?usp=sharing
Equalizer APO: https://drive.google.com/file/d/0B3fhrQO4W3XednpLVkVSLVphOXM/view?usp=sharing
 
Screenshots? Screenshots.
 

Hammy, remember this post?  You had suggested using the sonarworks calibration EQ profile for the 598s to help remedy the poor sound I was hearing out of my 598SE.  At the time, I thought it sucked the life out of the vocals, and didn't do a real good job of "fixing" the shortcomings of my inferior sounding 598SE.
 
Well, seeing as I'm not totally happy with the E10K, and considering upgrading it, last night, I decided to apply the sonarworks 598 EQ curve to my Ivory 598 and E10K combo.  This time, I really enjoyed the effects of this EQ profile, especially at louder volumes.  Bass boost turned off on the Fiio now, the bass really opened up, with lots more bass information and texture coming out across a broader range.  The mids and highs also sounded a lot smoother, the slight grain and slight sizzle virtually gone, allowing me to play the music louder and hear and feel the impact of the lows without the highs sounding too loud.  I guess you can say the music sounded more balanced between bass, mids, and highs, which is what a proper EQ is supposed to do after all.
 
Initially, going back and forth between EQ on and off, I wasn't sure which I liked better.  EQ off definitely sounded a bit clearer and cleaner.  EQ on sounded more balanced and smoother, with only a small hit to clarity.  I left the EQ on for a few hours of listening, and I thoroughly enjoyed it.  I didn't feel like I was missing anything.  I will continue to listen with the EQ on for a week or so to get used to the sound.  Then I'll turn it off and see which I prefer.
 
I think the SE I had was so far off Sennheiser's target curve for the 598, that the sonarworks 598 EQ curve, which is based on an average of frequency response measurements of multiple 598s, couldn't be properly applied.  My SE was too much of an outlier to be representative of the average.  So what I heard from the SE with the EQ applied didn't sound that good.
 
Ultimately, I feel the sonarworks 598 EQ curve did a very good job addressing the shortcomings I was hearing with the 598/E10K combo (lacking some bass quantity and depth, overall bright sound), that I may not end up upgrading the DAC/AMP at this time.  I still want to listen to alternatives however to hear for myself how much they improve the sound.
 
So thank you for that post about the sonarworks calibration.

 

[Hammy]

 
Hammy, remember this post?

 
Yep, that was pretty much my first attempt at EQing.  I forgot to enable the -7db preamp option so you'll want to do that.  I think both the 598 and 700 adapt to EQing quite well - maybe it's a Sennheiser thing. 

 
You're probably right about the E10K.  I haven't heard enough sources to have solid points of reference.  An iPad Air definitely sounds warmer but I had always assumed it was because it wasn't powering the headphones efficiently enough.  In some reviews the E10 was mentioned as warm in comparison to the E10K, so maybe that's what I was remembering.  If I upgrade from the E10K, I'd like to get something on warm side aswell.
 
Keep us posted after your trial period as to which you stick with.

 

[LazyListener]

  Geek Out 450 is USB powered only. And iDSD nano has both battery powered and USB powered. Geek Out 450 is discontinued now but you can see many of them on sale in For Sale/Trade forums in the last few months (because of the release of Geek Out v2)

Thanks!  It seems the iDSD nano always runs off battery power, even when connected to USB.  So, eventually, the battery will need to be replaced.  I don't really NEED battery power for portability, so I'd prefer not to have something with another battery to eventually replace (you know, save the environment and stuff).
 
I'll have to read up more on the Geek Out.

 

[trung224]

 
Thanks!  It seems the iDSD nano always runs off battery power, even when connected to USB.  So, eventually, the battery will need to be replaced.  I don't really NEED battery power for portability, so I'd prefer not to have something with another battery to eventually replace (you know, save the environment and stuff).
 
I'll have to read up more on the Geek Out.

I think you misunderstanding something. The iDSD nano have 2 mode. When you turn on the iDSD first then connect to the computer via USB, it will use battery power. If you connect iDSD to computer via USB first, then turn on the iDSD, it will use only the power from USB port, not the battery.

 

[LazyListener]

   
Yep, that was pretty much my first attempt at EQing.  I forgot to enable the -7db preamp option so you'll want to do that.  I think both the 598 and 700 adapt to EQing quite well - maybe it's a Sennheiser thing. 

 
You're probably right about the E10K.  I haven't heard enough sources to have solid points of reference.  An iPad Air definitely sounds warmer but I had always assumed it was because it wasn't powering the headphones efficiently enough.  In some reviews the E10 was mentioned as warm in comparison to the E10K, so maybe that's what I was remembering.  If I upgrade from the E10K, I'd like to get something on warm side aswell.
 
Keep us posted after your trial period as to which you stick with.

 
When I saw your post, I actually generated my own EQ profile from the sonarworks curve you posted, not because I didn't want to use yours but because I like doing that kind of stuff.  I later compared mine to yours, and there was really not much difference, nothing audible anyway.
 
As far as enabling -7db preamp, I messed with that last night as well.  I decided to leave it turned off.  It was causing me to have to raise the volume on the Fiio quite a bit, and I didn't really hear any distortion with it off, so off it stayed.
 
Are you using the sonarworks EQ as well with the 598?  I noticed they don't have one for the 700.  How are you liking your 700 so far?  Worth the upgrade?