My Nationite S:flo2 should arrive any day and i'd like a portable amp to go with it. The headphones are Sennheiser hd25-1 ii, I also have some HD650's.
 
After loads of reading on here, I thought the ibasso d4 looked pretty good, but now i'm thinking about getting a Headstage Arrow 12HE.
 
What do you guys think?
 

Definitely the Arrow, even if there is a possible 3 month wait.
 
I have the exact S:flo2+Arrow+HD-25-1 II combo
 
The iBasso D4 hisses. You don't want to have an amp to polute the dead silent line out of the S:flo2
 
Get the Fanmusic MK2 at ebay like I did if you don't want to wait for the Arrow. It matches the Arrow in sound. It just lose out to the Arrow in size and features. In my opinion it is the best sub US$100 portable amp.
 

Thank's for the reply, I'll wait for the Arrow - it'll give me something to look forward too
 
How do you find the S:flo2 + HD25's sound without an amp?

S:flo2's headphone out is quite ordinary. I find the HD25 sounds better when connect to the headphone out of my Lenovo X61 notebook (Analog Devices sound chip), playing through foobar/WASAPI.
 
One thing I just confirm this morning with the S:flo2: It sound better when an external battery pack is used as the power source.
 
1. S:flo2 being charged/powered by wall charger -> no difference in sound
2. S:flo2 being charged/powered by USB cable from computer -> no difference in sound
3. S:flo2 being charged by external battery pack -> no difference in sound
4. S:flo2 intenal battery fully charged, external battery connected and player draw power from battery pack -> more "airness", more micro details, more clear in sound.
 
All the above tested through my Arrow to RE0

It's a shame the HO out isn't that great - oh well...
 
That's interesting about adding an external battery. . . Before I got into Head-fi, I was an active member of the www.pinkfishmedia.net DIY room (I sold all my hifi because the girlfriend kept nagging me about it) One thing I learnt was the power supply is very important for achieving good sound quality. Naim preamps use large transformers and smoothing caps to produce a low impedance supply - the lower the impedance the better the dynamics.
 
A lot of crap gets talked on forums and sometimes it hard to know what to believe, but I can see how an extra battery could improve sound quality.
 
 
What type did you use and how did you connect it?

Quote:

fatmarley said:

It's a shame the HO out isn't that great - oh well...
 
....
 
What type did you use and how did you connect it?

Click to expand...

Though the S:flo2 HO does sound better than the HO of my other Dell D520 notebook using Sigmatel audio chip running Foobar/ASIO4ALL. I think the Analog Device SoundMAX audio chip in the Thinkpad X61 is actually quite good.
 
My battery is just a 3.7V 3000mAH lithium battery pack with 5V output through USB cable. I bought it to charge my mobile phone. Its capacity should not even be enough for a full S:flo2 charge.
 
See my posting on the main S:flo2 thread: http://www.head-fi.org/forum/thread/461156/s-flo2-impressions-thread/1740#post_6737307