Sony SCD-1 through headphones novice question

Hello everybody,
I'm an absolute novice, so forgive me if the following questions are too dumb.

I'm about to replace my old CD player with a Sony SCD-1 and will listen to it through headphones only. (currently Sennheiser HD-650 + Musical Fidelity X-CAN V3 headphone amplifier)

I-Can the headphone amplifier be connected directly to the SCD-1 or should it be a pre-amplifier between them?

II-What headphone amplifier would you suggest me to listen the SCD-1?

Thanks!