Reddit reviews Peavey KB 1 20-Watt 1x8 Keyboard Amp

It will be fine. Also, here's the same amp for 10 bucks less

Well, on a budget, I see three digital pianos that stand out. The Yamaha P-115, the Kawai ES100 and the Roland F-20. They have around the same specs. The differences are the number of voices, styles, speakers and polyphony and MIDI support and most importantly, Tone. They all support the three pedal assemblies sold separately and come with one. Also stay away from Casio. Their action and Tone are inferior.

Voices and Styles don't matter if you are playing the piano because a piano is not a keyboard.

As for Speakers, the Yamaha and Kawai have 2 7W speakers and the Roland has 2 6W speakers. This means the Yamaha and Kawai will probably be louder and will sound possibly better. I've only compared the higher end Yamahas and Kawais and not these particular models but i find their digital piano sound quite comparable. This will not matter if you practice with headphones or are planning to buy a separate keyboard amp which can go from an extra 100 to 300 dollars.

Polyphony in a nutshell is the number of keys you can press simultaneously that will be played through the speakers. The Kawai and the Yamaha are 192 while the Roland is at 128 but this shouldn't matter. 128 is for most people much more than needed.

The Kawai has a MIDI input and output port for digital recording as well as the usual headphone ports. The Roland has a USB port for digital recording and can connect to a computer. The Yamaha has just a USB to host connector which can record MIDI to your PC but no MIDI in unlike the other two. Here, I like the Rolands features the most and the Yamahas the least. None of this will matter if she records via AUX and MIDI does not matter to her.

Now Tone. I find Yamaha and Kawai to be very similar on tone and I prefer Roland to them. It sounds warmer to me which I like. Get your girlfriend to try one/any digital piano from each company to see which she prefers.

Overall, Id get the Roland because its more or less equal to the Kawai and the Yamaha but the 100 bucks more than the Yamaha gets me a tone I prefer. Then I'd get the Kawai because of MIDI IN/OUT. Else, I would have gotten the Yamaha. But the Yamaha is the cheapest and only loses features you possibly may not care about and has a very nice Tone too.

http://www.amazon.com/Yamaha-P115B-Digital-Piano/dp/B00UHBGE7A?ie=UTF8&keywords=yamaha%20p115&qid=1465281078&ref_=sr_1_1&s=musical-instruments&sr=1-1

http://www.amazon.com/Kawai-ES100-88-key-Digital-Speakers/dp/B00GXH4XVQ?ie=UTF8&keywords=kawai%20es100&qid=1465281051&ref_=sr_1_1&s=musical-instruments&sr=1-1

http://www.amazon.com/Roland-F-20-CB-F-20-Digital-Piano/dp/B00FB2THIS?ie=UTF8&keywords=roland%20f%2020&qid=1465282786&ref_=sr_1_1&s=musical-instruments&sr=1-1

Here are the Kawai and the Yamaha with the furniture stand, the furniture bench and the three pedals in a combo. I recommend you get one of these.

http://www.amazon.com/Kawai-Portable-Digital-COMPLETE-BUNDLE/dp/B01BFIRNOG?ie=UTF8&keywords=kawai%20digital%20piano&qid=1465283255&ref_=sr_1_8&refinements=p_36%3A-100000%2Cp_n_condition-type%3A404228011&s=musical-instruments&sr=1-8

http://www.amazon.com/Yamaha-P-115-Digital-Furniture-Style-Instructional-Polishing/dp/B00UOEBXBC?ie=UTF8&keywords=yamaha%20115&qid=1465283364&ref_=sr_1_4&s=musical-instruments&sr=1-4

And here are some good Keyboard amplifier to have a better and louder sound

http://www.amazon.com/Peavey-KB-20W-Keyboard-Amp/dp/B004LRP56W?ie=UTF8&keywords=keyboard%20amplifier&qid=1465283594&ref_=sr_1_2&s=musical-instruments&sr=1-2

http://www.amazon.com/Behringer-K900FX-BEHRINGER-ULTRATONE/dp/B000LQ29XE?ie=UTF8&keywords=keyboard%20amplifier&qid=1465283594&ref_=sr_1_3&s=musical-instruments&sr=1-3

If you just want to hear your playing, go with a good set of neutral studio headphones like the Audio Technica M40x for under $100.

If you don't want to mess with headphones, look at powered keyboard amps. NOT guitar amps - they color the sound by design. Keyboard amps are designed to accurately reproduce the source like the studio headphones.

Something like this, just choose how big: https://www.amazon.com/Peavey-KB-20W-Keyboard-Amp/dp/B004LRP56W/ref=sr_1_1?ie=UTF8&qid=1469028752&sr=8-1&keywords=keyboard+amp

No other box necessary, just plug keyboard line out into amp.

Edited to add: If you just want to clearly hear all the nuances of your playing, the headphones are probably your best bet. They cut out ambient noise, sound fantastic, can be amplified for about $100 if they're not loud enough for you, and are much cheaper than the keyboard amp.