Joy!
It seems I'm hopelessly addicted to dummy buffers (at the expense of additional current) but, depending on your headphones, you might find you can better hear what the Muses01 brings to the table, at least for a little while, if you go "bufferless."
This is analogous to something I once read at the forums of CoffeeGeek.com (paraphrasing): If you really want to know what your non-dairy creamer is doing to the flavor of your coffee, just fill your mug with hot water - not coffee, then add the usual amount of creamer and drink up. Keep doing this until you find one that doesn't taste nasty. And by the way, good luck with that!
I have yet to find an op-amp that is as transparent as a dummy buffer. That's actually a gross understatement, given that a dummy buffer is nothing more than conductors, but the transparency is just as obvious to my ears as the understatement is to my eyes. Even my best-sounding buffer (the HA5002) has a slight veil, best heard with something like the HD800 and a really noise-free DAC, like the Beresford Bushmaster MkII.
Lastly, just running the PB2 balanced out instead of single-ended gives me plenty of power (from two duals or four singles) for my LCD-2 or HD800. With the LCD-2, I typically run the volume knob somewhere between 9 and 11 o'clock, but let me be the first to say that I'm probably forfeiting some dynamics and bass control by running dummy buffers, as the planar magnetics prefer power (volts * amps) that comes from amperage (via buffers) rather than from voltage (via the op-amps in L/R).
And in truth, the LCD-2 is not ultra resolving, so I can tolerate the "veil" of the HA5002 when using the LCD-2, but I try to keep the lid closed on my PB2 - to protect my sanity from the incessant rolling of op-amps. I could easily get into pulling the HA5002 in and out, in and out, with the changing of headphones.
It's all I can do to keep the lid closed. As yet, I haven't resorted to putting Loctite Red on the case screws...
Mike
(Currently running 2x Muses02 with dummy buffers, after several months using 4x LME49990 with dummy buffers).