Rubix 24 channel volumes

[SH-09]

Hi, I’m trying out a live setup where I output 3 mono channels (backing track of synths, bass, drums) from Logic to 2, 3 and 4 and my System-8 playing live into and out of channel 1.

Probably missing something obvious, but as a test I sent the same output from a mono Logic channel strip to channels 1 or 2, and it’s very much quieter than if I output the same to either 3 or 4.

Are channels 3 and 4 set differently to 1 and 2, and so always going to be much quieter?