How to route from mixer to PC when using outboard equipment Please let me explain how I've recorded in the past since I think this will make my question clearer.

Microphone -&gt; direct into TL Audio pre-amp -&gt; direct into soundcard.


This is the only way I know how to route.

Due to the location of my equipment (mixer - it's a home studio), the mixer could offer the ease of accessibility so I want to understand more.

Now, I know I could apply the following setup:

Microphone -&gt; track 1 of mixer -&gt; direct into TL Audio pre-amp -&gt; direct into soundcard


But this doesn't seems like a good way, as it means that Track 2 of the mixer cannot use the TL Audio pre-amp.

I was also given a patch bay if that matters (or not).

How do I set up my mixer so I can use the outboard device? In total, I have 3 outboard devices and sadly only 2 send/return on my mixer. I do have 6 AUX though! The problem is AUX is just a send. 

This is where my head hurts. 

Let's assume my TL Audio pre-amp is connected via AUX 1. 

This would mean my AUX1 of the mixer goes into my SoundCard Port 8 and my DirectOut on the mixer (of Track 1) goes into SoundCard Port 1. It then means Direct Out of Track 2 of my mixer goes to SoundCard Port 2 etc.

Is this correct?
Since your question is not very clear, I will answer generally and then improve my answer if more information is supplied. First of all, it is important to mention that there are 2 types of audio effects: 


Parallel effects -  used with the original signal, without changing it. For example if you use delay or reverb; your signal gets routed to the effect and then returned back to your mixing console. At this stage - you decide what will be the correct mix between the original signal and the effect. 
Serial effects - affecting the whole signal, for example compression. Auxiliary channels in consoles are usually used to work with parallel effects. You send the original channel through aux to your effects processor and then route the processed signal(actual effect)  back to your return input. 


I say that to imply that usually you will not use your auxiliary sends and returns to use them with external pre-amp. The signal has to be pre-amped before going into the mixer channel, long before it reaches aux send point.

Regarding your question about direct outs and aux returns - yes, both of them will output the same signal as long as the aux volume is at maximum since both of them are post-fader.

If you want to use your external pre-amp with your mixer, you can use the line-in input which, in most mixers, is skipping the built-in pre.

EDIT1:
In some mixers the aux send\return are utilized by only one insert point, however internally tip is used as send and ring as return. This is from your mixer spec: