Yamaha A-s2100 vs A-s1100

Interested in the differences between these two amps, and also the quality of the built in headphone amp. Thanks
Not sure about those particular models but I have had the A-S500 (which I gave to a friend) and currently have the A-S2000 and it is superb.  I don't use it for my headphone amp so I can't comment on it but for driving speakers and the build quality I can't say enough.  I also have the CD-S1000 (bought used) and it is more musical than many of my dacs.  I feel like I need to unbox my cds that are in storage and listen to them again instead of wav/flac files played through several of my dacs.  
I use the A-S500 with my computer and am very pleased with it
From what I can see, the A-S2100 has (4) 22000 microfarads power caps and a fully balanced design while the A-S1100 has (4) 18000 microfarads power caps and is unbalanced.  Not much different between the two from what I can tell.


thanks willland

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@jl35 ,

Let me clarify my statement. I am sure there are more differences than I pointed out and the 2100 is a better piece, but I just noted what I know to be true.

I own the A-S1000 and I love it but would have no problem upgrading to either the 1100 or 2100 if funds permitted.

S/N ratios are higher by several decibels on the A-S2100 too.
the 6moons review seems to also indicate a better headphone amp in the 2100.  with the small price difference it is looking like the 2100 is worth the difference.  thanks all...