Originally Posted by Mad Lust Envy
I myself have the NFB5 which outputs the same power as the NFB12 (different internals though), and it sure does make the Q701 sing.
Have you tried the NFB-10? I was just about to buy the NFB-5 or the NFB-12 for my Q701 when the NFB-10SE was released, so I took the plunge for balanced operation. The amp is a great match I think, and for a sweet price. I used the single-ended headphone output for the few months it took me to get off my duff and rewire my Q701 and let me tell you, Q701 on a balanced circuit was quite the eye-opener for me.
I'm not well versed in different topologies, so I couldn't tell you whether balanced is the way to go or if the only determining factor was the higher output voltage, but to me it was like the exact same headphone, but the brain is on drugs. The instrument separation and microdetail were easier to discern. The soundstage seemed to stay the same, while I shrank into it, if that makes sense. Bass amplitude increased by a few crucial dB (empirically), so I think anyone who found it just a hair shy like I did would have a slightly better experience (though not compared to my bassier headphones). And compared to my previous headphone amp, the Presonus Firebox, I found that from either of the NFB-10SE headphone outs the highs were much less strident when playing some of the more taxing source material I listen to. I do think burn-in of the headphones helped too, but I do still think the NFB-10SE wrangled the top end with less fatiguing effect.
I'm actually surprised there isn't much widespread fervor for the Audio-gd products as there is for the M-stage with regards to the Q701. I know that when I was researching amps for the Q701 almost a year ago, the recommendations of each weren't as --- I don't know, weighted? -- as they are now. Lots of recommendations for the M-stage now. The NFB-12 is I think the same price, and AFAIK the connection options are more varied, which suits me personally. Also puts out a crap ton of power, which I had intended for a big ortho but is pushing my more modest headphones with lovely results.