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  • Writer's picturewei jie

Compare: Casio CT-S1 vs Casio CT-S400

$199.99 USD

$229.99 USD

The Casio CT-S1 and the CT-S400 are 2 of the newer model released by Casio and cause a stir. While both keyboards are similarly priced the CT-S400 is 15% more expensive. Both keyboards are a huge upgrade over the previous CT-S200 and CT-S300 with regard to sound quality, features and key action. For that I will be making an in-depth comparison between these two keyboards to help you make an informed purchase when looking to buy one of these keyboards.


At 1st glance, both the CT-S1 and CT-S400 look uncannily similar. However, there are a number of design differences which sets them apart, one of which is color choice. The CT-S1 is available in 3 colors red, white and black whereas the CT-S400 only comes in black.

The CT-S400 has a beautiful and functional blue backlit LCD screen which the CT-S1 lacks.

The fabric speaker cover on the CT-S1, which has a nice textured print, spans the entire width of the keyboard but do not be fooled, only the extreme ends of the fabric actually have speakers under it. The CT-S400 has 2 standard black fabric covers for the left and right speakers.

The CT-S1 has horizontal ridges which are not found on the CT-S400.

The buttons on the CT-S400 are made from soft touch material, whereas the buttons on the CT-S1 are hard plastic.

A red felt liner at the key pivots, usually found on acoustic pianos, is a nice design touch on the CT-S1.

While both these keyboards are made almost entirely of plastic, the chassis of the CT-S1 feels a little more premium. The CT-S1 prioritizes form while theCT-S400 prioritizes function. Both these keyboards have the exact same music rest that looks like overstocked items from the almost decade old Casio CTK keyboards.

It is regrettable that Casio didn’t carry over the brilliant music rest design from the CT-S200 and CT-S300. Both these keyboards have the same ultra-portable design, which is their unique selling point. They have the same compact dimensions, the same low weight with the same carry handle and guitar strap pins for ease of transport.

Both keyboards can run on AA batteries or with a power adaptor and support wireless MIDI and audio streaming with an optional Bluetooth adaptor.

Key Action

The Casio CT-S1 and CT-S400 have identical key action and key bed with the keys having a box-shaped acoustic piano keys design. While the action is not weighted, the keys require more effort to press than those on similarly priced Yamaha keyboards giving the Casio keys a semi-weighted feel.

The key surfaces are matte and lightly textured. Key noise is also significantly more subdued than Yamaha keyboards and previous Casio models. Those who prefer a quiet key action will not be disappointed.

While you get 4 velocity curves on both these keyboards, the CT-S1 has 64 notes of polyphony whereas the CT-S1 has just 48. The lower note polyphony on the CT-S400 is a deal breaker for more serious pianists.

Tone Quality and Effects

The number and quality of tones on these keyboards as well as the effects section will be the deciding factor for most of you. While both these keyboards are using Casio’s latest AiX sound chip, they cannot be more different.

The CT-S400 comes with 600 tones whereas the CT-S1 with just 61 tones has 90% fewer sounds. The CT-S400 essentially imports the tones wholesale from the Casio CT-X700 keyboard but the tones on the CT-S1 were specially designed by Casio. Most of the tones on the CT-S1 cannot be found in any of the existing Casio keyboard lineup.

While many of the tones on the CT-S1 share the same sample and the same instrument name as the CT-S400, the tones on the CT-S1 sound better. This is due to the CT-S1 having a more sophisticated effects section which the engineers could use to enhance the sounds.

While the factory preset DSPs, delay and chorus effects give the CT-S1 a richer tone however the downside is that none of these can be user configured. There is also quite a number of layered tones on the CT-S1 that are triggered by polyphony or velocity which a unique feature that is not found on the CT-S400.

Tones, such as saxophones, harmonicas, guitars, orchestral and ethnic instruments which are expected in portable keyboards in this price range are not found on the CT-S1 but are available on the CT-S400.

Further, the CT-S1 does not have a pitch bend wheel which the CT-S400 has. While both these keyboards support the layering of up to 2 voices, only the CT-S400 can have 2 voices split across the keyboards. This seriously limits the potential of the CT-S1 for keyboardists who often cover the bass part on gigs.

Rhythm Accompaniment Styles

Another major difference between these 2 keyboards is the rhythm section or a lack thereof. The CT-S400 comes with 200 accompaniments you trigger with chords to play-along with as well as a 100 pattern arpeggiator and 12 auto harmonizer. The CT-S1 has none of these features. If you don’t use any of these features, the CT-S1 may be a better choice for you.

User Presets

With the numerous ways to layer and configure sounds and rhythms, having the feature to save these settings for easy single-button recall is invaluable. The CT-S400 has 32 user presets compared to the CT-S1 which has just 7 user presets.

For those who pretty much play the same couple of tones, the CT-S1 7 user presets may be sufficient. However the flexibility of having 32 presets is a plus point.

Song Recording

While both these keyboards can record your performance, the one on the CT-S1 is a rudimentary single track, single song recorder. The CT-S400, on the other hand, has a significantly more sophisticated 6 track recorder, with the ability to copy and paste tracks, overdub as well as balance the volume mix and stereo pan position of each track

While the keyboards connected to a mobile DAW on your smartphone can do more, especially since these keyboards have wireless MIDI.

Sound System

Both keyboards have the exact same speaker system, driven by the same amplifiers and both keyboards are using the same bass port technology introduced with these Casiotones.

A nifty “surround” button which instantaneously expands the stereo width of the sound from the speakers which is useful when playing solo piano or electric piano tones. However the surround feature does not affect how the keyboard sounds over headphones or with the audio output to external amplification.

Ease of Use

If all you want to do on your keyboard is to play a piano, electric piano or organ tone, the CT-S1 simplicity works well. You just turn on the keyboard, select one of the 7 tone groups and select if you want a standard, modern, advanced or vintage tone and you are good to go.

However, you will need to have the manual with you to know which corresponding key to press to select the rest of the 61 tones or to use the other features such as reverb, transpose, metronome, voice layering, octave shift etc.

Casio went for form over function with the CT-S1 and removed all markings telling you the function corresponding with each key. The CT-S400, on the other hand, benefits from Casio’s large backlit LCD and revamped user interface. Every function is logically laid out and you will not need to refer to the manual.

However, this is not to say that the CT-S400 new interface is perfect. Casio has reduced many of the panel buttons compared to their similarly priced CT-X keyboards. As such, you cannot readily access both user registrations and rhythm controls at the same time, which is frustrating, as both features take up the entire screen.


Although both the CT-S1 and the CT-S400 are very similarly priced, to compare them both is like comparing apples to watermelons. Both are fruits but are very different in taste, shape and color.

The CT-S400 is better suited to an absolute beginner who does not know if he prefers playing just piano tones or would love playing with lush rhythm accompaniment styles. On the other hand, someone who buys the CT-S1 has a clearer objective.

He is a keys player, interested primarily in acoustic and electric piano tones and has little interest in other tones or having a rhythm accompaniment section.

Casio has clearly developed both these keyboards for very specific markets.

The CT-S1 will be well-received in America and Japan where there is very little interest in arranger keyboards.

Whereas, the CT-S400 will be well received in East Asia, Middle East, Germany and the UK where arranger keyboards with loads of tones and rhythms, especially ethnic and orchestral ones, like the Yamaha PSR and Genos sell well.

I hope that this review of the CT-S1 and the CT-S400 has been useful for you. Do check out the links provided in this article for the latest updates and prices of CT-S1 and the CT-S400. If these keyboards are not for you, do look at the other articles in this blog to find your ideal instrument.

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