Casio SK-1 & SK-5
Both of these keyboards have their own in-built tones and have the capacity to sample external sounds for use on the keyboard. In the case of the SK-1 only one sample can be stored,and in the case of the SK-5 up to 4 samples can be held at one time,or two longer ones.Both are monophonic rather than stereo and are 4-note polyphonic.
The SK1 has the following in-built tones: Piano,Trumpet,Human Voice,Pipe Organ,Brass ensemble,Flute,Synth Drums and Jazz Organ.
The Piano is passable,the Human Voice and Brass are impressive for something so small and the synth drums are useable,the Pipe Organ is also impressive - the other tones are what you would expect from an instrument like this.
The SK-1 comes with a demo tune and the capacity to record auto-accompaniment and and two melodies - or use the recording facility to just record the manual playing of the keyboard in full polyphony.The recorder uses the one key play method of the VL1 - which is useful - but overall the recorder is not easy to use. There is an ADSR envelope function to alter the volume dynamics of the sounds - this can be applied to any of the ROM sounds or the sample.
There is also a chord programming function and a Fourier synthesis function,as well as a drum machine.
The chord programmer allows various chords to be programmed by use of the root note and one other key which chooses the chord type.
The Fourier synthesis mode adds harmonics in 16 stages and 9 footages to create a new sound - the result ought to be impressive,but tends to produce similar organ sounds - it is a pity this function was not given more attention by Casio - and then you would have not only had a sampler,but a synth with ADSR. It is rather rare for any keyboard to offer Fourier synthesis,so as an introduction to the method - this is the cheap route.
Samples can be looped and can be taken from an internal micropone or one of two external sockets,one for line in and one for an external microphone. There are also controls for vibrato and portamento.
Good points: The brass,organ and human voice are impressive for such a small instrument and the overall package offering so many things to do, keeps your interest. The samples are low quality but still useable and the fun of using any sound on a musical keyboard cannot be understated,when looped and enveloped you can make some very odd noises.
It is possible to add MIDI control - circuit bent models are available on Ebay and the MIDI modification is available online.[maxmidi.com/diy/sk1/article.html]
Niggles: Some of the ROM sounds are toy-sounding - the editing system for the memory is not easy to use,though it is better to have one than not. The drum sounds suffer from low quality too.The Fourier system could have added a wider range of tones,but only ends up making organ-variants that are largely unuseable.
The SK-5 is similar to the SK-1 but the Fourier synth has been dropped in favour of larger sampling capacities.It too has an internal microphone and sockets for line in and external microphone,although the sockets are located on the right-hand side rather than the rear as they are on the SK-1.
There are only 6 ADSR shapes as opposed to the 13 on the SK-1.There are also less ROM voices: Piano,Dog,Trumpet,Chorus,Vibraphone,Surf,Pipe Organ and Flute - The Organ and Chorus are the only ones worth using and it is quite sad that Casio chose to drop some of the better sounds from the SK-1 in favour of animal samples.
The SK-5 has 8 drum pads on board - 4 of which have ROM sounds and 4 can be used for your own samples. The ROM ones are Lion,Laser Gun and low and Hi Bongos - it might have been better to have made these Bass and Snare drum and open and closed hi-hat.
The other 4 pads will either contain your 4 short samples or your two long samples depending on whether you have chosen to sample 2 sounds or 4. One benefit of the SK-5 over the SK-1 is the ability to tune the sample,which means once it is sampled - it can be rendered in tune with the keyboard's on-board sounds - this is one thing which let the SK-1 down - making the samples largely unuseable in music.
The SK-5 can also reverse the samples in memory,which is something the SK-1 could not do.
The SK-5 has one less rhythm on the drum machine,which also is rather toy-sounding. It's memory does not work like the SK-1's and is not able to be edited.This rather lets the SK-5 down,as the memory basically loops around what is recorded and is not synchronised to the drum machine - it also has accompaniment modes but no chord programmer - but has several demo tunes which are chosen from the lower 7 white keyboard keys - a medley of which can be chosen by the last white key on the keyboard.
Good points: The capacity to store 4 samples or two long ones and tune them cannot be underestimated. If you want a cheap but useable sampler then this is a tad better than the SK-1 and the looping memory means you can use the samples as a backdrop for other music. Playing polyphonic samples was something I never thought I'd see at this price in my life time - the fun element is the main reason for hearing these keyboards,though apparently they have been used by performing DJ's!
Niggles: The SK-5 suffers from the same toy-sound as the SK-1 and few of the preset sounds or rhythms are useable - basically they are an afterthought to the idea of a sampling keyboard. Checkout Yamaha's VSS keyboard,which probably offers better ROM sounds as well as sampling.