Hi gang...thought I might give my initial impressions of the Apogee Duet Mic Pre/Converter that I've recently acquired, in case someone might be doing a search on the device.

Apogee recently added Windows driver support for the Duet, ( available for download at Apogee.com) which was previously only able to allow the Duet to be used on a Mac. The new drivers for Windows are solid, installed easily, and the Duet integrated quickly and seamlessly with Samplitude Pro X.

The Duet is a 2 channel USB mic preamp/interface; it uses a breakout cable, with two multi-format inputs, allowing XLR, Line and Instrument Inputs. The format is chosen in Apogee's Maestro Control software. This is where you can also select other features such as 48v, Phase and set both input and output levels ( which are also adjustable on the Duet itself.)
The breakout cable also provides two balanced outputs,which you could connect to your monitors,or, if you want, to another external device.
The mic Preamps have a gain rating of 74db, providing plenty of input gain for both dynamics and ribbons. The Preamps are transformer-less, the sonic results being very clean... So if you're looking for a preamp with analog "character", this isn't the preamp you would want.
The built-in 1/4" stereo headphone amp has quite a bit of gain.

While my main motivation for getting the Duet was to take advantage of Apogee's well-known reputation for making great conversion, I really do like the mic Preamps; it provides me with options for tracking that I didn't have previously. I already had several different "character" pres, two solid state transformer based, and two tube models, (not including my PreSonus VSL 1818, which was also functioning as my main interface)... And I had been thinking about adding a "clean" preamp for awhile now to round out my sonic options, so the fact that the Duet has two very clean hi-gain Preamps pleases me in that regard.
The Duet also gives me the option of using the above mentioned external mic Preamps without using the Duet's Preamps. I can connect my ISA One, ADK AP1, or any other pre I have, and bypass the Duet Mic preamps, sending the signal from an external pre directly to the Duet's conversion stage. The Duet model I have supports SR's up to 192k, though I doubt I would ever track that high, not in my current computer, anyway.
The Duet can also be used with an iPad or iPhone...though I haven't tried it with either one of those devices yet.
The other thing I like about this device is its portability. It weighs in at about a pound, so taking this and a laptop to a friend's house, coffee shop, hotel room, airport, etc. is super convenient. It would also be great for live stereo recording as well.
I haven't had the occasion to do any of those things yet, but knowing I can is definitely a plus.

I love how my ISA One sounds through the Duet's conversion, and being able to connect it and bypass the Duet's Preamps is a really nice option... Though I need to say again that the mic Preamps in the Apogee's are great... Beefy, clear, and quiet as the grave.
This definitely steps up my game... along with my recently acquired ISA One.
For the recordings I do at home, hardly ever needing 8-16 channels at once, I'm very impressed by the sonics that I'm now working with.
Even playing back tracks and mixes I'd previously done using the PreSonus for tracking are benefitting from the Apogee conversion. There is absolutely a greater clarity and definition there that I wasn't getting with the PreSonus VSL. It's not a placebo effect, or "power of suggestion". The sonics I'm hearing ARE better. The difference is not subtle... At least not to me, anyway. I'm very accustomed to the way my rig and my room sounds. The Apogee absolutely does provide greater clarity, definition and a "bigger"sound than the PreSonus does.
On that note...
I can't knock the PreSonus 1818 I've been using for several years, it has definitely served me well, and for the money, it allowed me to do some great work along the way...but this recent gear update has most certainly stepped up the sonics of my gain chain to another level. If I'm lucky, maybe it can even help to pull me out of the creative slump-writer's block I've been dealing with lately. ;)
If you are searching for a device with two very nice mic preamps, great conversion, and, portability too, consider the Apogee Duet.
That's all. :)
-d.