A karaoke amplifier with a built-in mixer is an ideal solution if you do not already have a mixer because you can connect your karaoke player, microphones and speakers to this and mix the sound directly from the amplifier without using another mixer.
Having the mixer built into the amplifier gives you an easy way to set volume levels and effect levels to get the most out of your karaoke system.
Most karaoke amplifiers with a mixer built in will have at least two microphone inputs with controls for echo and volume. There will be at least one input for the audio from your karaoke machine. If your karaoke machine has a microphone input you may want to consider using the microphone input on the mixer and not your karaoke player because that will make it easier to mix and get a nicer sound for your singers.
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