Sam Spoons wrote:This is for vocals and acoustic guitar so the line inputs/pads are not really relevant. The Mackie's analogue eq might be worth having but, apart from that, the 'analogue sound' is unlikely to be significantly different from the digital sound the interface (with it's analogue pre amps) produces.
For the OP: if you want to have some "analog" sound, a good option is to save for an external preamp (or borrow it) and run it cranked - something you usually can't really do on an interface (since you can't bring the level down again to avoid overloading the converters) and you probably don't want to do on the Mackie mixer (these kind of mixers are often engineered to work well and sound ok within the performance envelope of their component, not outside).
Certain specific preamps, however, tend to behave nicely when pushed. And get something with a transformer. I use a 610 for example which really sounds nice when cranked on vocals and bass. It's just distorting but it does it in a nice way. Same goes for pushing a 1176-like compressor - sometimes. An inexpensive option is the Golden Age Pre 73, which is quite nice than pushed. Since it's Swedish plenty people have it around there and I'm thinking of getting one for good myself instead of borrowing.
However: important to say that all that is just for fun. These days you can get pretty much the same analog feel in the box - so long you record properly and process with the right effects. The 610 emulation of my Twin (with its Unison preamp) sounds pretty much the same as my hardware unit, and for free and instant analog magic I do still recommend and use the glorious 32 bit BootEQ MkII from Variety of Sound.
But nothing wrong with having fun!