Behringer Ultratone K900FX 90W 3-channel Mixing Keyboard Amp


84 out of 100. Incorporating 325+ ratings and reviews.

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Behringer Ultratone K900FX 90W 3-channel Mixing Keyboard Amp

Gearank High Notes

Gearank Recommendation

The Ultratone K900FX appeared on our recommended list for Keyboard Amps From $200 to $300 from the time we first published it in May 2016 until we removed that price category in March 2022.

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Audiofanzine stompboxjon 80/100
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The Ultratone K900FX is another example of Behringer providing an amp with a higher power rating than their competition deliver at the same price level.

This one is a 3-channel amp delivering 90 Watts of power via a 12" woofer and a 1" tweeter.

It also comes with onboard effects and Behringer's FBQ Feedback Protection System which is helpful if you use the amp as a compact PA system or to amplify acoustic guitar.

Note the the XLR mic input doesn't have phantom power so you can't use most condenser mics with it, but that's not too much of an issue because most singers use dynamic mics on stage.

If you need to sing through your amp, as well as putting your instruments through it, then this is a good low price personal PA and Keyboard Amp combination.


  • Output Power: 90 Watts.
  • Number of Channels: 3.
  • Inputs: 3 x 1/4", 1 x XLR, 1 x RCA (Stereo).
  • Outputs: 2 x 1/4".
  • Speakers: 1 x 12" Woofer + 1 x 1" tweeter.
  • Tone Control: 5-band EQ.
  • Frequency Response: Not specified.
  • Size: 17.375" x 16.875" x 11.75".
  • Weight: 41.45 lbs.
  • Manufacturer Warranty: 3 years.
Although this was previously on our recommended list, there are now more highly rated options available which you can see in our guide to The Best Keyboard Amps.