Your Proceed has a very nice low output impedance of 20ohm, and should be used direct into your KSA150, as I believe your doing, any added preamp between the Proceed and KSA150 will degrade the sound quality.
I believe there is an input pre-set level control on your Proceed, this should be set so that the Master Volume is at 1/2 to 3/4 full for normal loud listening.
This will give you the best (lowest) noise figures, as your using the max output from your source and not attenuating too much just to make it up again with the gain stage of the Proceed
Cheers George