I have the SM-101 MK-II mono blocks too. These amps are very sensitive to power cords. I use a custom built power cord made of silver (bulk wire from Analysis plus). These amps change their character based on what you feed them, so choose wisely and depending on your preferences. They are that transparent. If it sounds very warm now, change to silver power cords and they will reward you with extreme transparency & silver sound.
Regards,
Sudesh
Regards,
Sudesh