Sound card choice

I have recently been engaged in a thread about the popping that I have been hearing when listening to tracks that I have just recorded. I was using an older  M-Audio Delta 66 sound card. After weeks of having no success, I simply  bought another sound card. Unfortunately, the name doesn't sound like any I have heard of before. I was told that I could return it if I didn't open the package. I just want to know if anyone out there has experience with a Fast Track Duo Audio Interface Box. I bought this instead of an internal card, such as the one I had. I assume they do the same thing.
My hardware includes: 
Sonar Producer 8.5, Midisport 4x4, Intel i5 650 @ 3.2 gHz, 6.0GB RAM, 64 Bit OS. Mackie 14 channel mixer; various synths
Thanks.
Larry

Seems fine, But for the same cash I would have bought one with MIDI ports so everything is in one device. 
Hope it solves your driver issue. Make sure and remove your old card first as PCI cards often get in the way of USB devices. 

I just looked up the available drivers for this audio interface, and I caution you that:
 
1.  This interface is no longer sold by Avid, but it does have support until 2018, but I wouldn't hold my breath for drivers getting updated.
 
2.  The currently available drivers for this interface do go up to Windows 7, both x32 and x64, but there are no specific drivers available for Windows 8 or 8.1, meaning it may or may not work in Windows 8/8.1 using Windows 7 drivers, so you need to be careful with upgrading your OS beyond Win 7.
 
I do not know how much you paid for this interface, but here are a couple of links to some basic interfaces, that DO provide current support and have drivers for Window 8 available:
 
http://www.guitarcenter.com/Focusrite-Scarlett-2i2-USB-Audio-Interface-107041253-i2162367.gc
 
The above is a Focusrite Scarlett 2i2 USB interface, for about $150.
 
And one from Presonus, that also has midi ports:
 
http://www.guitarcenter.com/Presonus-AudioBox-USB-2X2-USB-Recording-System-104841978-i1388074.gc
 
Of the 2, I think the Focusrite likely has a tad better converters / pre-amps, so since you have a midi interface already, you might consider this slightly better than the Presonus, but truthfully either one is fine.  I actually use a Presonus audio interface - just has more inputs and outputs, but works great.
 
Bob Bone
 

Thanks for that input. As I said, I had just bought the sound card because this Sam Ash is 1/2 hour from me and I figured I could return it before opening it. IT sounds like the  Focus 2i2 or2i4 might be best for me. Of course, that Roland sounds pretty good as well, and, since it comes bundled with a Sonar product, might be easier to use with my Sonar. However, when it says that the Roland has better mike pre-amps, does that mean that if you plug in a non-amplified signal such as a mike, it will boost the sound in a cleaner or more transparent fashion? Or does it mean that anything plugged into it, such as the output from my mixer, will probably sound better thru it? As I think I've indicated, I'm not plugging any mikes into my interface. When I look up again at what was said above, someone also talked about much higher sample rates. Thus, it does sound like there would be a potential for the sound to be truer--ie, I might be able to hear a cleaner or closer to the original sound-when using one of the sound cards that are being recommended here.
 
Cactus Music: thanks for telling me to remove my existing sound card from my PCI slot. I never would have done that.
 
I also appreciate the comment about the potential lack of support in the future, which is the problem I'm having with my Delta 66 right now.
 
I'll just have to do some reading on the difference between the FOcusrite 2i2 and 2i4. Right now, I have a 4-4 MIDI interface, though perhaps that's not what it's referring to. Figuring that out should be  easy enough.
 
Oh yes, needing only 1 USB port to hook up to instead of 2 is very big. Using 2 more USB ports would mean I would no longer have a free port.
 
Lastly, I think that Steinberg UR22 and Prosonus also sound good. Perhaps if that's all they had when I go back to Sam Ash, either would be pretty good also.
 
Thanks again for the input, though I won't be able to go back for a week. I'm just hoping that when I finally hook up my new sound card, I won't hear any more popping!
 
Larry