For some Euros I ordered from a Chinese EBay-seller two DVB-T-USB-sticks. They are based on the receiver chip RTL283U. In combination with free Software and a simple up converter this dongle gives access to the frequency range from 100 kHz to more than 1 GHz. This means, that you can use those sticks as broadband scanner or low cost spectrum analyzer with limited accuracy.
This is a very simple audio amplifier with up to 2 Watt output power. I use this amplifier to drive my speaker with the soundcard. The sound is in excellent quality.
With one single TDA2005 you can build your own stereo ampliefier, which I placed in a slot of my PC case.
If your computer won´t turn on in the cold or if your computer shows a blue screen and reboots several times, than your computer and the psu is propably affected by failed capacitors.