[albee1952]

First stop is the pdf manual for pro Tools as it (should) have a section on "hardware inserts". Then, the outputs of the oo3 are indeed numbered(mine are anyway) and setting up an insert path is done in the IO setup section, Inserts tab. Basically, it tells you to select a matched set of IO(such as input 5 AND output 5) to be a hardware insert path. Then you can insert that path in place of a plugin on the track. Assuming you are running PT8(since this is the LE section) you won't have delay compensation, in which case, I would simply set the output of your vocal track to any open output and feed that to the LINE input of the Tascam. Feed the LINE output of the Tascam to any LINE input of the 003(5 thru 8 would be good for this, set to the +4 position on the rear switch(on the 003). Create a new AUDIO track and select that line input and maybe engage Input Only monitoring(Alt-K), with the Tascam track in record-ready, while you adjust the settings of the Tascam(expect there to be a small latency, but ignore it for now). Once your settings are good, Hit Alt-K again to revert to Auto-Input monitoring, put this track into record(and record the vocal processed thru the Tascam). Once recording is done, zoom in at the first bit of waveform and look at the original(unprocessed) audio, and nudge or spot your new audio so its lined up with the original(now you have compensated for the latency and your new audio should be in perfect sync with the track). Don't try to listen to both the original AND the processed tracks together as they will phase against each other(just a byproduct of the processing). If you have PT9 or later, you can enter a delay compensation amount in the IO setup section and skip the later part about nudging. Sorry this is so long winded, but I wanted to cover all the bases for you.