Yamaha SK10 / SK20 / SK30 / SK50D

Yamaha SK10 Image

Yamaha SK-10

Yamaha's SK-series are combo-keyboards with synthesizer, organ, brass and string sections. The SK-10 was the first of the SK-series, released in 1979 - the SK-20, 30 and 50D followed in 1980, and the SK-15 in 1981, possibly as a replacement for the SK-10. The SK-10 is the only one in the series that does not incorporate a synth section, but has organ, brass and string sections that can all be played together for more interesting combinations. Very sturdy casing, 4-octave and fully polyphonic the features also include a leslie simulator, vibrato, attack and sustain rocker switches, a slider for 'brilliance' and a one-octave transpose switch. Not exactly feature-laden, but a lovely string synth sound. Interestingly, they are often referred to as 'analog', but in fact do have a digital section. Its organ has one of the early implementations of Yamaha's FM technology in a very limited form, concurrent with the GS-1/2 development platforms which eventually led to the DX series.

The ORGAN SECTION is available in all the SK series synthesizers. It offers a full range of stop levers from 1' to 16', percussion levers with adjustable decay, and controls for overall sustain, brilliance and decay. This gives you quite a lot to work with in the way of synthesis. The organ's sound is FM based and it sounds very B3 like. You can add a Vibrato and a noisy but good Tremolo to it. Its sound is all about the 70's era rock organ, especially with the Ensemble chorus effect in use. It also has a Leslie-speaker output around back.

The PRESET STRINGS section isn't very sophisticated and offers very limited editing capabilities. It is the string section though, that is worth aquiring this keyboard for. Very similar to the best of the string synths, (such as the Arp Solina/Omni or the Logan String Machine) it has a sound reminiscent of the opening of 'Oxygene' (J-M Jarre) or the lead line from 'Love Will Tear Us Apart' (Joy Division).

Yamaha SK-20 Image

Yamaha SK-20

The SK20 adds the POLY-SYNTH SECTION: a 7-note polyphonic synthesizer with basic filter, pitch, envelope, and portamento controls. It features two (detuneable) oscillators per voice so it's good for thick pads. It lacks any bite whatsoever and, even in normal attack mode, has way too slow an envelope to be used for any bass or percussion sounds. But, the pads and strings you can get certainly shine and glitter like Bowie a-la Ziggy Stardust (especially when layered with the Strings section). It's like a good entry-level synthesizer. Basic and simple LFO, filters and ADSR envelopes. It has a built-in sustain and the Tremolo and Ensemble chorus effect also apply to this section.

Yamaha SK30 Image

Yamaha SK-30

The SK30 (weighing in at over 90 lbs.) and SK50D also feature a SOLO SYNTHESIZER SECTION which is a single VCO driven mono-synth similar to a Roland SH-101. It has basic pitch, waveform, filter, volume, envelope generator and portamento functions. Its resonant filter isn't great and can't be driven into self-oscillation. The keyboard's after-touch can control the vibrato, tremolo, and brilliance effects. You can effectively play leads in the solo section while simultaneously playing chords in the string, organ or poly-synth sections.

Yamaha SK50D Image

Yamaha SK-50D

The SK50D adds the Bass section as well as an additional second keyboard stacked above the other! The BASS SECTION provides an independent set of tone generators and controls for a deep, rich organ bass sound. It has its own set of stop levers, as well as sustain and brilliance controls.

All the different sections of the SK synths can be layered and stacked via the slider bars. You use the slider bars as a mixer to set the individual volume for each section. All sections have their own separate audio outs (though a mix out is also available). A great thing for live performances is the split keyboard mode. That way you can have, for example, a very nice, punchy bass sound from the synth section and a lead sound coming from the organ or solo sections. Although it has no patch memory, there are push buttons for instantaneous selection of organ, poly-synth and string preset sounds; there are three presets in each section. It also, has no arpeggiator or sequencer, and lacks MIDI. But it's cheap, easy to use, has a nice sound, full 61-note keyboard, and classic wooden panels. The SK's have been used by The Constantines, DJ Logic, Sigur Ros, and Ben Wa.

Lookup Yamaha SK10 / SK20 / SK30 / SK50D Prices

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53 Visitor comments
May 1, 2011 @ 10:55 am
My ebay SK 20 arrived yesterday. I love the sound of this keyboard. Put stereo FX in front of the strings and there's nothing better for that 70s string synth sound. But mine behaves strangely....

On mine, the first note (of the synth section) steals the envelope generator. If I hold down the first note and start a new note, itr rides along the first note's envelope until the envelope completes. For example, if the first note has a bright attack, all extra polyphony loses its attack until all notes complete. Is that normal or do I need to get mine serviced? Thanks for any advice!
December 14, 2010 @ 5:26 am
Ich bin etwa 1990 zu meinem SK 30 gekommen, ihn auch einige Jahre in der Band genutzt, nur auf die Dauer wird mir das Ding zu schwer. In meiner derzeitigen Truppe nutze ich den tiefen Analog-Bass 16"-Sägezahn für die Untermalung zu "New year's day" und bei "Twilight zone". Werde wohl zu einem Nord Lead umsteigen und den SK bei Ebay anbieten, mal sehen.
December 10, 2010 @ 12:22 pm
I have an SK15 and am quite pleased with it. paid about $350 - road case included! it's not as huge and heavy as the 20/30/50 and slightly larger than the 10. as the description says, it's as step up from the 10 with the poly-synth section added but i use it mostly for the b3 clone, however layering the poly-synth and strings on top of that can really thicken up the sound (my reverb and 2 equalizer pedals also help - different settings on each that i can switch to/from to get some variation in sound when i'm using both hands). highly recommend picking one up. you don't see them that often.
November 8, 2010 @ 1:43 pm
SK-50D was also used (along with ARP Odissey) by the Latvian (ex-USSR) instrumental synthpop band Zodiac, very popular in the 80ies :) free MP3 downloads here, very nice compositions:

October 18, 2010 @ 7:27 pm
What about the SK-15?
VSE Rating

It’s Good

User Rating

Rated 4.35 (824 Votes)

  • Check Price
  • The link above will take you to an eBay search for this synth to see active listings. If you don't find it there, try looking in our forum marketplace or post a wanted classified.
  • Specifications
  • Polyphony - 7-voice polysynth and string + Full FM organ + monosynth
  • Oscillators - One VCO, two in polysynth section
  • LFO - One with Sine waveform only (leslie simulator - 2 speed)
  • Filter - Brilliance control, Resonant low-pass 12dB filter (non-self-oscillating)
  • Envelopes - rocker switches for attack and sustain
  • Effects - Vibrato, Tremolo and Ensemble effects for the organ and poly synth string sections.
  • Keyboard - 61 keys (122 keys on SK-50D)
  • Memory - No user memory. 3-preset patches per section.
  • Control - CV-Gate IN/OUT
  • Date Produced - 1979-1980
  • Resources & Credits
  • Images from Audio Playground Synthesizer Museum,
    and Andrew Heaney.

    Additional information provided by DAC Crowell, Mikael Bengtsson, Michael Bonanno, Andrew Heaney and Patrick Coleff.

    Reviewed November 2007.

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