I used the phono section of the A-S3000 for a while with an Ortofon Quintet Black. It was really good, but I moved up to a Parasound JC3+ as I was still wanting more out of my vinyl. Compating the two, at the same volume setting, the JC3+ is easily ~50-60% louder than the on-board phonostage and at the same time ~75-80% lower noise floor. I would say if you are just getting into vinyl and have any MM cart or a more musical MC (think like a Quintet Blue or Cadenza Bronze) then the on-board phono would be perfect for you. If you have a higher-end table and are hungry for dynamic range, "slam", and power/presence at lower volumes, then you will want a higher-end separate.
Hope that helps! Glad to hear others enjoying this fine Yammy!
Hope that helps! Glad to hear others enjoying this fine Yammy!