Yes, a proper audio interface will be better than an adapter particularly if you do lose the fear of getting software and venturing further into this (we already assume this will happen, it’s inevitable, it’s so much fun!)
I’m not familiar with the particular unit Saffire 6 (it’s a lot newer than than the WX7 and VL70-m and will help you bridge that time gap from 20th to 21st Centuries. :-). A quick look at the specs I see it is a USB 1.1 interface... you’ll need to check to find out if the software you eventually get can deal with that. (USB has been good about backward compatibility... but you’ll want to check on that).
But for your initial goal, you’re in good shape. The Saffire has both MIDI jacks to connect the VL70-m and a way to communicate audio.
WX7 MIDI OUT to the VL70-m MIDI IN; then VL70-m MIDI Out to the Saffire 6 MIDI IN, Saffire 6 USB to your computer. The computer will refer to the Saffire 6 for MIDI. In other words, when setting up don’t look for “WX7” or “VL70-m”, the computer will see ‘Saffire 6’ Midi In and Out.
The USB connection to the computer is a two-way, port connection (In and Out) and will allow you send MIDI data from the VL70-m into the computer. If you connect the 1/4” audio outputs of the VL70-m to the Saffire as “Inst” (Instrument) inputs, the Saffire will send the audio of the VL70-m into the computer and it be able to receive audio back from the computer software... all via the single USB connection.
Use the recommended Driver for the Saffire (check the Focusrite web site). The reason is the manufacturer knows their product better than a generic driver and since it has MIDI and Audio it’s simply wise to do so.
The Saffire 6 will connect to your speaker system or you can use Headphones... connected to the Saffire.
Word about Software...
All software that you don’t know or are unfamiliar with, looks complicated at first glance. And when you know it, it stops looking complicated and unfamiliar. Funny how that works, Every Time! Never buy anything simply because you can figure it out at first glance... you usually wind up outgrowing it in very short order. Expect to climb a learning curve. That is part of the fun... truly it is.
The biggest buyer’s regret is buying something that looks easy only to find out later it doesn’t really do what you need.
If you can figure it out completely before you know anything, it might be a good thing, but most often it’s because it doesn’t really do much.
Most of all, have fun! If you get stuck you can always come back here...
Extra Credit:
You are joining a fraternity of musicians who have found Wind MIDI Controllers a very rewarding experience. You‘ll want to bookmark the following website, as it’s a link to others who can help you with maintaining and getting the most out of your Yamaha WIND MIDI Controller... from a horn players perspective. Breath Control sounds programmed by keyboard players are usually not challenging enough for musicians who play (or who
used to play actual) wind instruments. So you will want to appreciate this difference.
The site is run by a guy named Matt Traum... if you already know about, forgive me for preaching to the choir, but if you’re new to it, ... you're welcome!! (They’ll think a WX7 is a classic)...
http://www.patchmanmusic.com
Enjoy!