ok then just plug the DAC/iphone into your Arc Pre and be done with it.
Why go through the Sony if you have the Arc Pre go through the Arc as with the other inputs. Just note you will not get all the advantages of the Flac files but it will, even through your phone, sound better then mp3. get a apple to RCA adapter and go into one of the Arc's inputs skipping the sony all together because yes it will degrade the sound as you are going through a lot more circuits. just use the sony as your tuner.
Why go through the Sony if you have the Arc Pre go through the Arc as with the other inputs. Just note you will not get all the advantages of the Flac files but it will, even through your phone, sound better then mp3. get a apple to RCA adapter and go into one of the Arc's inputs skipping the sony all together because yes it will degrade the sound as you are going through a lot more circuits. just use the sony as your tuner.