T21's Double Drive 3X is one of the least raved about products in the Tech 21 range. Perhaps this is because it is SO versatile and very sensitive. It does require some 'getting to know you' time and yields great rewards if you give it that time. Because the tone controls are active and very sensitive, it is quite easy to make adjustments that might be termed 'overkill'. So if you factor that into your relationship with the machine you'll have better luck dialling in the tones you're after. Go easy, is my advice. The two drives are also very reactive to one another and again, another learning curve is warranted but rewarded for time spent. I like it. :)
As usual, I ran my guitars straight into the pedal and then into my Laney VC50's Clean channel. A Violet Design 'The Amethyst' microphone carried the signal to an M-Audio ProFire 610 which in turn fed Logic via my MacBook Pro. I kept levels in check with Waves L316 Limiter on the output.