I believe that if you attach Master Fader 3.x to the DL1608, that it will require a firmware update. But if you attach Master Fader 2.1.1 to it, it will require a firmware update back to 2.1.1 The correct firmware is always kept with the Master Fader app. (It's really just the mixer's software to work with the ipad's software.) You've got the same thing with StudioLive computer software and the Presonus digital mixers. In that case, every change of software version or computer make results in updates. (Mac and Windows friendly, but don't expect to use the firmware for the Mac on the Windows computer.)