[geezer]

....To begin with, you have to, have to, have to start clocking everything from one central point as much as possible as soon as you start mixing multiple digital sources.....All the old stereo digital devices will clock to their input, but the mixer will need to have all its inputs (digital) clocking to the same clock or will start producing subtle and not-so-subtle garbage in the audio. Digital is great for its stability, but is only stable when everything is clocking together.

I worked without a central wordclock (clocking the mixer to the digital recorders or vice versa) for a long time and worked with it, but really needed the central wordclock when I started getting into bigger track counts. The sound changes when you get the central clock, and may take a day or so to get used to, but is definitely more stable and solid.

I'm using the Rosendahl Nanosyncs, which seems to have the largest number of features for the price(video sync, 2x and 256x outputs, 6 wordclock outputs, 4 video outputs). The Aardvark clocks are considered very good, and, for a simple clock, Lucid makes a very good box for cheap with 4 or 6 outputs.

Clock stability has a significant effect on how any D-A converters you have will sound, too. This, in fact, seems to be the single largest factor in the quality of a D-A converter, which means it is the single largest factor in your ability to hear in the studio.

Do you need the A-D/D-A on the hard disk recorders? It depends on how you work, but I do. The converters on the MX2424 are considered very high quality and are inexpensive per channel. I do a lot of live recording and tend to bang mic pres right into the MX and then mix from the digital outs, so they are great for me and give me a lot of other options for interfacing to analog gear......Converters are generally good enough these days that the quality arguments are more subtle. The converters on the DM2000 are way better than the ones on the 02R, and are definitely eminently usable. Some folks consider them a little "grainy", but, like I said, converter quality is way up these days.