khaine nailed it!
The NFB-27 standalone (DAC+AMP) is closer to neutral than, say, a Ref 5.32 (dark) + SA-31 (warm). I wonder how close to this combo the Ref 10.32 is (in tonality that is).
Like all Audio-GD gears, the NFB-27 still has a hint of warmth in it, but IMO it's not enough for the bright/airy hifimans. Even for the HE-5LE I prefer pairing it with the SA-31 (on its most neutral setting). This setup is almost perfect in tonality (for me, again).
Swap the 5LEs for the 6s and it becomes too bright again. I think I must set the SA-31 on "warm 1" level to get the tonality I like but I didn't try it yet.
With the Eximus DP1 - which is brighter than the NFB-27 and closer in tonality to the Metrum Quad (what I consider neutral) - I set the SA-31 on "warm 2".
I used to do the same with the Quad when I listened to the HE-4.
In summary, my preference (in no particular order) goes like this:
- NFB-27 + SA-31 (neutral) + HE-5LE
- Metrum Quad + Stello U3 + SA-31 (neutral) + HE-500
- Metrum Quad + Stello U3 + SA-31 (warm 2) + HE-4
- Eximus DP1 + SA-31 (warm 2) + HE-6
-
NFB-27 + SA-31 (warm 1) + HE-6 (TBC)
HE-4 and HE-6 can be interchanged. HE-5LE and HE-500
cannot.
Edit: sadly, I didn't have much time to try the HE-500 on the NFB-27 standalone because I could not get it to sound good back in the days (glare/hardness & all these nasty things). I sold the HE-500 to fund the HE-5LE even though I expected the NFB-27 to be an all-in-one replacement for the Stello U3 + Metrum Quad + SA-31 that I could use with the 500s and be done with it.
Now that I can enjoy the NFB-27, I regret that I sold the HE-500 (more precisely, that I didn't buy Prep's balanced/hard-wire HE-500 when the offer came...
).
I'm quite certain I will end up getting the 500s again at some point.
