Now that I have upgraded the HifiMAN HE400S with Mogami cable (Focus A pads already installed and not going anywhere!), I have fired up the R2R-11 again over the last few days and discovered that not only has the R2R become even more alive at nearer the 500 hour mark (just as Kingwa said it would), the HE400S now sound rather good with this DAC/amp!
Something has definitely happened to the R2R, as it has become even 'faster' and more dynamic that it was quite some hours ago, no matter what headphone I use with it. Dynamic range seems to have expanded and the sheer speed of drum kits and guitars has somewhat shocked me, bringing even more life and drama to the astounding dynamics on Ani DiFranco's Living In Clip pair of live albums, damn that woman can play! Andy Stochanski on drums reminds me of a cross between animal on Sesame Street -
- and Keith Moon but with more refinement. Wow. I have simply not heard the R2R like this before and although, no, it does not resolve the fine detail and sublime focus that I get through the Mimby/Slinkylinks silver cables/Elekit TU8500 valve preamp and hot-rodded h/phone amp, it is just so much fun to listen too while being different! And a lot less cabling and space taken up to boot. It seriously kicks butt down the bottom end, with both weight and taut focus, there is a visceral aspect to the R2R's amplifier which I really like, seemingly unfazed by anything at all. Love it for that. Value for money is outstanding for an all in one package and I'm a big fan of the build quality.
Since there is plenty of grunt to power the HE400S (they're still not that efficient, despite the 22 ohm impedance .. my 600 ohm HD540 Ref1s are still actually easier to drive initially) I switched between hi and lo gain and the difference now seems to much clearer between the two. Although you get a slightly punchier more dramatic sound with the gain on high, switching to low gain there is definitely a greater refinement and relaxation of the soundstage into a more open listening experience, the various instruments tend to spread out a little into their own space, where going back to high gain crams things up a bit and in last night's case, added a little cramping of the s/stage and a touch of coarseness to the treble. I preferred low gain with that album in particular. That visceral bass impact lessens only very slightly, yet retains the focused punchy tautness and detail, actually better balanced from top to bottom in some cases.
I couldn't hear such differentiation a month or two ago and now it's quite obvious after quite a few more hours on the R2R-11. The upgrades to the HE400S have allowed me to hear things more clearly now - the Ref1s are always brilliant, but it's the HE 400S I like with the R2R, a bit of a turnaround now that they have their much better cable, as if they are better driven now.