Cary CAD-300sei vs Sun Audio SV 300BE match for JMlab Micro Utopia

Question like in topic
older version of micro utopia ( with tioxid tweeter )
Which one of this amplifier will be better match for this speakers ?
I know answer now
Sun Audio 300b is beauty match to this micro utopia speakers
But new question:
In this system I have only one source
Sun Audio is poweramp with two potentiometr 
Use it with or without preamp ?