I recently helped out at a local community event where a musical production was being presented to members of our local community as a means of highlighting the centre's facilities and activities.
I had access to a laptop as the sound source and set about editing the music samples I was given and arranged them in play order, the only problem was that the laptop had a very "middle of the road" audio system and thus the sound lacked any real dynamic range.
I found the answer to my dilemma on Amazon with the Creative Labs USB X-Fi Go Pro USB sound card, the installation was a doddle as was the setting up of the software.
The dynamic range of the device is amazing, there was the additional benefits of a mixer and reverb effects that made the audio output far more bright and crisp.
In all a fairly inexpensive way to get great quality sound from a laptop which was not fitted with a decent output device. The output from the device is via 3.5mm stereo jack and can be switched from a line output to a headphone output via a small slide switch on the unit, it also has a stereo Microphone input via 3.5mm jack, and has a removeable cap to protect the USB conntecor when not in use.Creative Labs 70SB129000002 Sound Blaster X-Fi Go PRO USB Sound Card