In the absence of a karaoke player, it will be successfully replaced by an ordinary desktop computer or laptop.
All you need is a sound card, a microphone and an internet connection.
Make sure you have an audioCard (separate or embedded in the motherboard). If you do not have one, purchase and install it. Remember that this can only be done with a de-energized machine. If you do not have the appropriate skills or desire to upgrade the machine, purchase a special external sound card with a USB interface. Make sure that it has a microphone input.
In the Linux operating system, configure the audioCard in the sndconfig utility, in Windows - install its driver. If there is no sound, look at the settings of the mixer - maybe it just has a minimum volume setting.
Connect a special sound cardComputer electret microphone. If there is none, do not use a special dynamic karaoke microphone - the sound will be very quiet. To make a homemade microphone, use an electret cap, designed for a supply voltage of 1.5 V. With a three-volt sound will also be quiet.
Make sure that the microphone is working. If this is not the case, restart the mixer and turn on the microphone input. Set this volume so that there is no acoustic feedback. If you can not fix it, place the microphone away from the speakers, or use headphones instead.
Install the latest version of the Flash Player plug-in on your computer for the combination of the OS and the browser you are using.
Find sites with karaoke files, for example http://www.karaoke.ru/. Select the work and proceed to its execution.
Electret microphones have the following disadvantage: They can not be connected in parallel. The microphone input of the sound card is just one. This does not allow singing alone, as when using specialized DVD players with a karaoke function. Correct this disadvantage by using the cheapest mixer that you can find. In addition, it usually allows the connection of dynamic microphones. Connect the console output not to the microphone, but to the line input of the sound card.