an 8x8 audio interface would be good (thuis means you can record 8 things onto 8 different channels on your daw (or 4 stereo things)

4 inputs for 2 gameboys
4 outputs for 2 eqs
4 inputs for the eqs

BUT if you are using a computer you really can get a much better EQ for free on software than you will get on a cheapo behringer thing (no doubt hardware is fun and nice to play with though) so if you don't have the hardware you can get away with a 4x4 which are cheaper and smaller if you want

buying an audio interface CHANGED MY LIFE:)

1. The 802 only has one FX send bus, there isn't a separate physical FX send/return per channel.
2. The FX send bus is after the channel level controls, so at the main effects FX return you'd have a (processed) duplicate of the signal coming from the channel, raising your noise floor. This configuration is mainly for sending a 100% wet FX signal to the returns, to fade in just the effect (not original + effect). To EQ each gameboy separately, either get a mixer with channel inserts and put the EQs on the inserts, or run the gameboys directly into the EQs then the mixer. 
3. No amount of precision in an EQ is too precise, that is entirely up to you. 31 bands is a lot, but a high resolution graphic EQ allows you to draw the exact curve you want whereas with fewer bands (say, the three on the mixer) you are limited to the crossover points and of that eq.
4. Complaints of noise/sound quality with Behringer is 100% bullshit considering you're recording from a gameboy, which even with prosound mods will have more background noise than Behringer products. Build quality varies from product to product.

I see the words USB audio interface and USB mixer.

Sie haben einen Laptop?

http://www.google.co.uk/products/catalo … CCwQ8wIwAA

Buy a few, you wont regret this!

PULSELOOPER: Just bought the cables and all, thanks!

e.s.c.: Alright! Thanks, I'm gonna wait a while on the EQs for now. I'll keep in mind your suggestion.

youll probably be fine just using the built-in 3 band EQ for any live stuff, for recording id just tweak the EQ a little more in your recording software

you'll need two 3.5mm > 1/4'' stereo cables for your gameboys and a 3.5mm > RCA stereo cable for outputting the audio mixdown to your computer. Pretty simple, pretty cheap. Be sure to buy your cables in a place you can trust. I have the same cables since 2008 and they never gave me any problems (they smell beer though)

Awesome! It's a sexy price too haha. What channels should I use for recording the gameboys? What kind of cables do I need?

yeah man, I only use the 1002 for studio work, recording me and my mates playing shit live. But I love the 502 for travelling, it's so tiny and I never use more than two channels anyway. You'll be happy with your 802!

e.s.c. : Oh that sucks. Really? What kind of EQ would you recommend?

InactiveX: I asked my stepdad (who is a DJ) and had no idea what a send nor return was, so I'm guessing they don't.

PULSELOOPER: I'm probably gonna stick with the 802 due to buget concerns, so that comment made me happy!

my two behringer mixers (xenyx 502 and 1002) never let me down.

you do know that the aux sends on mixers are basically always mono, right? ive been cursing this fact for years..if youre going to do stereo 31 band eqs (which is excessive for shaping the sound of a game boy) for each one, itd have to be inline, not through the AUX send

I don't know, you'd have to ask a DJ and see what's available. Do you need send and return, or can you pu your effects and stuff in line?

I really can't agree with this! Overloading an input is user error, pure and simple. The quality of modern cheap sound hardware is extremely good - you have to spend a lot to get a good deal better. And if bass response is lost irretrievably, then something is very badly wrong with your recording technique anyway.

I agree with your other points though!

You're trying to do multiple things here, and the tough question you have to answer is whether you want to do each of these things before or inside the computer. You want to:

mix the stereo signals of two gameboys
EQ each of the stereo signals separately
get the audio into your recording software

One at a time:
Mixing: If you mix the signals before the audio hits the computer, their relationship is permanent. If you record the two gameboys onto separate channels in multi-track recording software, you can adjust the mix freely.

EQ: same as mixing - the only downside is that if you do a bunch of live EQ work, then you will need to either buy a controller for your software to play the effects the same way, or simulate your EQ tweaks using automation.

Getting audio into your computer - you can survive by just running the output of a mixer (or straight from a gameboy) into the line or mic input on your computer, but it won't get you nearly as far as having some kind of proper A/D. You'll find that the input is easy to overload, the quality doesn't stand up to other recordings, and you may lose bass response that you won't be able to get back with EQ.
This interface can come in the form of a standalone device, or can be built into a mixer, although googling right now I can't find any models of USB mixer that output more than a single stereo signal - I know they're out there though.

Basically, this is what I'm trying to achieve. With both gameboys being stereo.

InactiveX: Hmm..a DJ mixer would be interesting. Do they have send/returns on the channels? I really just wanna make sure i get stereo for both gameboys.

why would you want mono anyway?