There are three ways to to go from balanced to single ended :
1. use a transformer
2. combine the + and - signals with an active circuit
3. just use the + signal as Atmasphere recommends
Both 1 and 2 would have to degrade the signal in some way.
The bigger question is why do you want to stay fully balanced to the input of the amp? If you are going to use that preamp with an SET amp you have to convert somewhere so why not do it as the manufacturer recommends?
FYI your CD player is not really "fully balanced." The information that is encoded on the CD is not balanced so the player is somehow creating the minus signal.
1. use a transformer
2. combine the + and - signals with an active circuit
3. just use the + signal as Atmasphere recommends
Both 1 and 2 would have to degrade the signal in some way.
The bigger question is why do you want to stay fully balanced to the input of the amp? If you are going to use that preamp with an SET amp you have to convert somewhere so why not do it as the manufacturer recommends?
FYI your CD player is not really "fully balanced." The information that is encoded on the CD is not balanced so the player is somehow creating the minus signal.