We have been waiting for a model like this for many years! The 150M sounds great, weighs low, and is so versatile its much more than a keyboard amp, check out YAMAHA:

Power to Go!: From the company known for market-leading electronic keyboards come a new generation of keyboard amplifiers that redefine the category: STAGEPAS 150M and 250M. "How are they different from what's been available?" you ask. In almost every way! They're much lighter and more compact, provide a unique form factor and feature set optimized for keyboardists, and, most importantly, deliver the ultimate in sound quality. Both of these single-speaker systems also function very effectively as ultra-portable mono PA systems that are upgradeable to stereo with the simple addition of an optional powered speaker.

Flexible 8-channel Powered Mixer: The STAGEPAS 150M provides a total of eight input channels: two mono microphone/line inputs and three stereo line inputs. Along with the output for the supplied speaker, the built-in yet detachable mixer also has line outputs that can be used to connect additional powered speakers or to send the mixer's output to a main mixer or recording device. A convenient PHONES jack is also included for connecting a set of headphones.

Exceptionally Compact System – 8 Channels, 150 Watt Output: 150 Watt Class D Power Amplifier This power amplifier is all you'll need for most small venues and street performance situations, as well as personal monitoring applications. The advanced Class-D design delivers exceptional efficiency – ensuring high power amplification with low power consumption and minimal heat generation. This means you get superior sound quality and reliability in a remarkably compact unit.

Ideal for Monitor Speaker Use: The STAGEPAS 150M is also effective as a monitor speaker system (especially for keyboard players, drummers and solo performers), thanks to its fullrange reproduction, convenient mixing controls, and versatile speaker placement.

Other Features:
> Detachable Powered Mixer
> Two-way Full-range Speaker System
> Built-in EQ and 1-bit Modulation Reverb
> MUSIC / SPEECH Switch
> Auto Limiter
> LED output level meter
> One Speaker Cable Supplied