I have owned quite a few audiophile amps; tube integrateds & separates from Primaluna, Jolida, audio research and quite a few solid state behemoths like Krell, Rotel, etc. Nothing compares to sound quality of the Yamaha as2100. I was delightfully surprised at its presentation. A perfect balance of resolution, warmth, tonal color and frequency extension. Build quality is equally pleasing both the aesthetics and tactile feel. I like the phono stage too. It is on par or better than some ~ 1k standalone phono stages. My LFD phono stage has only a slight edge over the built in phono of this unit. The built in phono beats the discontinued PS audio GCPH (1k when new). This is undoubtedly a true high end amplifier and definitely recommended to audiophiles.
I would recommend this to a friend