One thing to consider is that if you are using a computer, you don't need phono preamps necessarily. A phono preamp has two functions:
1) Level amplification. The output of a tone arm is very high impedance and thus even a fairly short run of cable will mess with the sound. Not a problem in the case of a USB soundcard, just put the thing right there and have a cable run only inches long.
2) RIAA equalization. In this case not a problem since you are digitizing the signal. Just have your computer apply the EQ.
Now depending on what you are doing, it may be much easier to just get a phono pre, however if you goal it record records on to your PC, you might wish to just forgo it. A digital EQ on your computer will be much more precise than what you are going to get in a cheap pre in a soundcard.
Excuse the side issue... but if you're serious about recording LP's to CD, you really want that RIAA EQ done right, and in the preamp. The RIAA EQ curve's purpose is to de-emphasize the low end, and pre-emphasize the high end... due to the way the grooves get cut. Kind of the same as speaker displacement, you get a huge increase in excursion as you go lower... this minimizes it.
Magnetic type cartridges are pretty low in impedance, but the signal strength on all of them is very small. You have to add a huge amount of gain, probably more than a regular soundcard input can supply. Due to the gain (>60dB?) needed you want a very clean preamp, as well as an accurate RIAA EQ.
Key issue, we're talking about 20dB between one end of the spectrum and the other. Most basic digital EQ sliders don't have this much adjustment range, as well as only a few bands of EQ, so it would be hard to do. Also, it's not a flat curve, kind of a dual slope with a flatter kink in the middle, if you don't get it right the record won't sound right. It's such a lot of dynamic range to add later, it's much better to add it at the beginning of a recording chain.
Most phono preamps are within a few percent of the RIAA standard, if you want better, buy a medium quality outboard one. (check out Jim Hagerman's Bugle kit/built preamp as a very nice example, for instance)
Sorry to jump in with this for those just using the card for REW... doing quality dubbing of LP's has been a hobby of mine. For REW of course it's a non issue. Just don't plug the mic into the phono input by mistake! If the non phono '202 really does have an overall flatter response down to 10hz, though, then it's the better choice of the two for measuring. It's possible that the phono model has some kind of rumble/infrasonic filter, and that it includes all inputs rather than just the phono. That would roll off your low end response. Of course, making a sound card cal file could make up the difference...
