If you want to use a compressor when tracking, hook it in to the insert connector of the ART DPS-II pre-amp. This takes the signal out after the pre-amp and returns it before the A-D converter. Don't use much compression at this stage - it's not easy to undo when mixing.

You need not be worried that the insert jacks on the DPS-II are unbalanced, as the compressor has only single-ended output, dressed up as pseudo-balanced. Watch out for the pre-amp's insert jacks being wired the unconventional way, so if you use a standard insert cable, interchange the usage of the "send" and "return" TS plugs.

Thanks so much for the reply Boswell. Now that you mention inserting the compressor on the mic-pre I can definitely see the reasoning behind that. That makes alot of sense.

I have one other question for you Boswell...let's say I want to use the compressor at mixdown. Would I connect the compressor to the Presonus?

What are you using for mixdown?

If this is "in the box", i.e. using a software DAW, you must weigh up the advantages of using the native DAW compression tools and/or software plug-ins versus taking the signals out again, compressing them via outboard devices and feeding the compressed signals back into the DAW. Compression is not like reverb, where (usually) the quality main signal remains in place and only additional effected signal is added. With compression, the whole channel is operated on, so you must take into account any degrading effects of additional D-A and A-D conversion, and also the necessity to get the time alignment right after going external.

If you are mixing "out of the box" (externally), it all becomes easy, and you insert the compressor in the vocal channel much as you did when recording.

To use the FireStudio Project with an external compressor when mixing ITB, the easiest thing to do is to take the raw signal to the compressor out of a FireStudio line output and take the compressor output to the line input of a different FireStudio channel.