The Yamaha SK15 is an Analog/Digital synthesizer made in Japan in 1981. It is a synthesizer called "symphonic ensemble", it offers 3 different sections: A "ORGAN" section, a "STRINGS" section for synthetic violins sounds and a "POLY-SYNTH" section which is a polyphonic synthesizer. Each section can be used independently or combined to create a wide variety of string machines typical sounds. The Yamaha SK15 offers a "slow attack" effect that can be assigned to the Poly-Synth and Strings section, allowing you to create more natural string sounds. The Yamaha SK15 also features a BRILLIANCE setting that affects the ORGAN and STRINGS section. The SK15 also offers an adjustable VIBRATO. The Poly-synth section offers a very musical filter with an envelope dedicated to the filter ... And of course, like any good string machine there is an TREMOLO/ENSEMBLE effect applicable to the STRINGS" or/and "ORGAN" section... Our opinion is that the Yamaha SK15 is a good String Machine that does not offer a huge variety of sounds but simply a STRINGS section that sounds great, an organ section that sounds great and a simple polyphonic synthesizer that sounds great, you will find very quickly your own settings, that's why the Yamaha SK15 can be used in live. Note that the Yamaha SK15 construction is high quality with good durable materials and a high quality of assembly, it is a very solid synthesizer. Here and there on the internet it is noted that the Yamaha SK15 is a new version of the SK10 which is not true; In fact, the Yamaha SK15 is a simplified and more portable version of the Yamaha SK20.
