After 8 years of service I believe that the DL1608 is EOL (End Of Life). Mine was RIB (rest in box) after 2 years and replaced by the X32 (2014) and subsequently by the more comparable XR18/MR18 (2015).
Here are some of the remaining issues and workarounds.
1. Pin one problem poor grounding scheme injecting noise into the audio signal path.
http://cacophony.aspinock.com/index.php?topic=383.msg2566#msg2566Solution is a correct external power supply. The problem was never addressed by Mackie.
2. Sync problem with docking connector.
Although 3rd party apps such as Voice Record Pro 7 seem to fix this problem, MF 5.1.1 does not. Probably by ignoring some of the "special sause" status signals. Past reports here found audio to continue playing but control was lost.
With schematics (sheet 5) recently provided there may also be a hardware solution to improve the USB 2.0 audio and control messaging that could be made more robust. A common mode choke (L26) needs to be jumpered (Mackie even made provision for this with R514 and R515 with jumpers un-stuffed) to improve the signal quality. They may have left the choke in to meet EMI specs but it degrades the signal. Here is a snippet on the subject discussion from StackExchange regarding common mode choke usage in USB signal lines:
"The USB signal is not entirely differential, so it's not a great idea. (The end-of-packet (EOP) signal is both pins pulled low, which, I believe, is why there's always noise at 1 kHz and harmonics in USB systems, since it's sending common-mode signals every 1 ms.)".
I have not implemented this and may never since I have really never used the MF record/playback function. Software workarounds exist with more features such as the a fore mentioned Voice Record Pro 7. Alternate hardware solutions may be superior from an acoustic point of view depending on your usage of recordings.
3. The 5.1.1 known issues list of 20 is inflated with some ridiculous issues such as undocking the iPad will suspend recording/playback. Most others are minor issues or only pertain to the other DL mixers. I have not run into the random show creation bug.
4. Over the 8 years since introduction many software issues have appeared but were eventually fixed such a the white noise problem. The replacement mixer for this is the DL16S/DL32S models, unfortunately little was added to keep up with the competition or even the DL1608. See my comparison.
http://cacophony.aspinock.com/index.php?topic=1447.msg17201#msg17201 or the competitions
http://cacophony.aspinock.com/index.php?topic=1436.msg17113#msg17113 This was a promising mixer when introduced but Mackie had no follow thru or prompt response on mixer issues (white noise).
Time to fatten the piggy for market while there is some demand for this.
