This little portable 16/48 USB ADC/DAC is yours for $35. Carry it in your laptop bag; connects a pair of RCA inputs or a pair of RCA outputs. Use it to connect a turntable, tape deck, instrument, or analog mixer.

The Xenyx line of USB mixers comes in various sizes and gives you a nice combination analog mixer; 24-bit ADC/DACs; mic preamps; and extra goodies such as special effects, equalizer, compressors, monitoring ports, faders, and auxilary sends. Plug in all of your performers, adjust the mix, and these little mixers will output a ready-for-CD stereo recording. The Xenyx line ranges from $270 for the X1204 to $500 for the X1832. Windows, Linux, and Mac.

Rackmount USB 2.0 24-bit/96 kHz, 8 preamps, 8 XLR/TRS combo jacks, 2 headphone outputs. $499. Includes drivers for Windows and Mac, reported to work on Linux with stock ALSA drivers.

My own little two-channel workhorse. Accepts up to four devices, such as two mics and two instruments. 16/48 ADC/DAC, nice knobs for gain control, headphone monitoring port, two mic preamps, phantom power, bus-powered, stereo input and output, line ins and outs. $179. Windows, Linux, and Mac.

PreSonus makes nice audio hardware, and this little box is a nice value. You get a two-channel bus-powered preamp ADC/DAC with phantom power; it is very portable because it is small and doesn’t need an external power supply. It has two combination TRS/TLR plug-ins for dynamic mics, condenser mics, or instruments; nice knobs for controlling gain; two MIDI ports; and a headphone monitoring port. $149. Windows, Linux, and Mac.

16/48 kHz ADC for connecting a standard turntable to your computer, for both recording and playback. $199. Windows, Linux, and Mac.

Slick little XLR-to-USB microphone adapter with phantom power, 16/48 ADC, and mic preamp for both dynamic and condenser mics. Plug your favorite mic directly into your computer. $150. Windows, Linux, and Mac.