I have a GK 800rb and a GK 1001rb. My intention is to use each to power a 8x10. They are both in a rack. I did this with 2 8x10s before using a Y cable to go onto both front inputs. I don't know why but I had many problems with cables/connections so I scrapped it for 1 head. I miss my sound. Now, my thoughts are to run a cable off my rack (a preamp) into the front of one of the heads. I would then run a cable from the FX send on that to the return on head #2 thereby using it as a Poweramp only for the second Cab. I'm sure this will work BUT I'd really like to be able to adjust the preamps on BOTH heads the 1001 has stuff the 800 doesn't BUT the 800 has "the" sound. I could get another 800 but no $ right now plus the1001 has 240w more power. Eventually I plan on getting a 2001 head and eliminate all this.