A USB connection lets you convert analog into digital and feed it directly into your computer. This sounds a whole lot better than the typical sound card.

 
The Bellari VP530 Tube Phono Preamp with analog and USB digital outputs.  Only $399 and Free Shipping

The VP530 builds on the basic circuit built into the rave-reviewed vp129.  The VP530 adds a switch to turn off the RIAA (phono) circuitry so you can use your own eq curve if you like.  The exciting aspect of the VP530 is the built in Burr-Brown PCM2901 Sigma-Delta analog to digital converter. This high-quality A-D converter converts the signal from your turntable into an easy to use digital bitstream that connects to your computer via its USB port.  Now, you can easily turn your archive music on vinyl into very high quality computer files for dubbing onto CDs or straight into your hard drive. 

Features:
• Switchable RIAA Equalization
•All tube circuitry
•Burr-Brown Sigma Delta analog to digital converter
• Switchable Rumble Filter
• Mute Switch
• Headphone Output w/variable level control
• Steel Chassis
Specifications:
• I/O Connectors, RCA, 1/4" TRS Stereo, USB
• Input Sensitivity: 30 dB gain
• Input Impedance: 50k Ohms
• Output Impedance: 8 Ohms Headphone, 100 Ohms RCA
• Max Output Level: >10dB @ 1kHz at .1% dist.
• Equalization: RIAA +/- 1.5 dB, 20Hz to 20kHz
• Rumble Filter: 20Hz
• THD .02% @ 1KHz
• S/N Ratio: >80 dB unweighted
• PWR: 12 - 18 VDC
• Size: W6 x H2.5 x D5.4 in.
• Weight: 2 lb.
• Indicator: 1 Power LED