Splitter on gpa 555!pre amp output


I have had two bridged Adcom gfa 555s since 1989 into 4 speakers. Is it safe to buy a one into two splitter for the left and right outputs on my pre-amp so I could run each amp independently for each pair of speakers?

ramm440

Each of the gfa 555 input impedance is 22kohm, using a splitter your preamp will see a 11kohm load.

If your preamp output impedance is 1kohm or lower it should be fine, otherwise the low frequency output will reduced. 

The pre-amp is a GFP-555. Would you think/guess this is a better way to run these two amps vs bridged in mono? I will search for the GFPs output specs. Thanks