Nick The Man said:
i dont understand how those work...
How what work? The ADAT input?
Say you bought
the Onyx 1640 (the 16 channel, 4 buss board). It's got 16 direct outputs on two of those DB25 connectors we talked about earlier. You would get two of the cables that have DB25 on one end and 8 TRS on the other. Direct outs 1-8 would go to the 8 line inputs on your Tascam. Direct outs 9-16 would go into the line inputs on your ADAT converter (the ADAT converters I mentioned are the Alesis AI-3 and Behringer ADA8000...both affordable and seem like they would be adequate for your uses). The ADAT converter has an ADAT fiber optic output. You get an appropriate fiber optic cable, and go from the convertor's ADAT output into your Tascam's ADAT input, labelled "ADAT/Optical In".
Another option would be to sell the Tascam and just get the Onyx and the FireWire card for it. The only downside to this is you're giving up any versatility and future upgradability that you have with the Tascam. I personally wouldn't do it, but that's just me. With the Tascam and 8 channels of ADAT conversion, you have 16 simultaneous channels of recording that you can patch any system into. If you're mixing in the box, then it should be more than you'll need any time in the near future. If you want to mix out of the box through the Mackie, you'll have to learn to pare your tracks down to a total of 16, either through more judicious tracking or by using submixes, but this is not necessarily a bad thing. There's no law that says a song has to have 30 or 40 tracks of music for it to sound good.
I think one thing that you're going to see is starting to rear its ugly head is the high cost of cabling things up. The more channels and effects you have, the more cabling adds up, and quickly. Personally I have a 24x8x2 Allen & Heath board into an Alesis HD24. Just to patch the two together I have an 8 channel snake from the buss outputs of the board into the Alesis, and a 24 channel snake patching the Alesis back into the board for mixing. I'm moving next week and I plan to patch two rooms of my house together with 32 channels of cable between the rooms, which is going to cost me several hundred dollars and countless hours of my time soldering everything. It's worth it though, because high quality cable is going to last for a long time and probably won't give you any troubles such as trying to find out where the one bad cable is that's causing that annoying hum or hiss.
So basically, if you took my advice (which is nothing more than how I would personally expand on things if your setup was my own), I'd be looking at the following:
Mackie Onyx 1640 board
(2) DB25 - TRS Male connectors
8 channel ADAT A/D/A convertor
Word clock cable for clocking the Tascam and the ADAT convertor together
Also, you have an M-Audio TAMPA, correct? I would patch that into the Tascam's SPDIF input, for a total of 17 simulaneous channels of recording.