Hello Komoyuki,
Do you still have your Rogue Audio RP1 pre-amplifier for sale? I am interested in purchasing it if so. I live just outside Calgary, Alberta and I'm not sure where you currently reside so I would need to contact you to discuss in greater detail. I will try to send you a PM about this, but not sure if the system will allow me to as I am a new member.
Thanks
Don Yue