I think this is one time I was thankful another headphone amp failed and I was forced to seek out a replacement.  I stumbled on the Sennheiser HDVA 600 with it's balanced inputs, balanced pass through outputs, enough headphone outputs for (2) sets of balanced headphones and (2) sets of 1/4" headphone plugs.  This headphone amplifier is beautiful, modern, elegant, what you would expect from Sennheiser engineering.  I chose the HDVA 600 for two reasons:   1.  On both my larger and smaller audio systems I already have the SABRE DAC in play, so I did...