Paul offered a good explanation of the function of a phono stage to which additional explanation is not required.
I do have a question about your motivation in asking about the NAD though. Do you already own this unit? Are you considering buying it with the goal of moving into seperates at some point?
The reason I'm asking is that a dedicated phono stage can be purchased new or used for less than the cost (typicall) of a pre-amp. The dedicated phono stage will (typically) work better than one that was just added to a mid-quality pre-amp. It is not my intention to ridicule the NAD, but better stand alone phono stages will offer you a more direct signal route. Remember, every connection is a loss of signal. Shorter signal routes sound better.
I do have a question about your motivation in asking about the NAD though. Do you already own this unit? Are you considering buying it with the goal of moving into seperates at some point?
The reason I'm asking is that a dedicated phono stage can be purchased new or used for less than the cost (typicall) of a pre-amp. The dedicated phono stage will (typically) work better than one that was just added to a mid-quality pre-amp. It is not my intention to ridicule the NAD, but better stand alone phono stages will offer you a more direct signal route. Remember, every connection is a loss of signal. Shorter signal routes sound better.