CASIO SK-1 - The legendary MINI-Synth that brought Sampling to the Masses!

-> Underrated and not full explored - Very usable as it comes (!) - Highly desirable for modifications and circuit bending for endless sound possibilities! As it comes in stock configuration:

• One sample 4 voice polyphonic Sampler - built-in Mic + Line/Ext Mic sampling Inputs - sampling offers: one shot or to loop the sample
• Synthesizer function (that allow to create diverse sounds from scratch): -> Organ type tone generator (additive synthesis!): 9 "draw bars" with 14 level steps each (see last photo)-> Envelope generator: 13 different envelope curves can be applied to any sound -> "Effects" that can be applied to any sound: PotaMento, Vibrato
• Rhythm machine that is unique to Casio and it's sound so 80's - 11 Rhythms with "Fill-in" function
• Sequencer: enter notes, then add their rhythms by means of the "one step" keys - 3 track sequencer: solo1, solo2 and chord - a desired mod (not included, but can be added at additional cost): to trigger the "one step" keys with an external sequencer to sync this synth up with your rig
• Keyboard Pre-Set Sounds: Pipe Organ, Trumpet, Human Voice, Piano, Brass Ensemble (nice good synth patch!), Flute (great with portamento + vibrato), Synth drums, Jazz Organ

Today the SK-1 is maybe even more beloved than ever! - The SK is perfect for those vintage 80's cheesy sounds - It's drum pattern "Rock1 " was used by the German Band "Trio" in their 1982 Hit "Da Da Da" - this original sound and do much more is right here at your finger tips!

Lot: Excellent to "near mint" condition Casio SK-1 in original stock configuration - no modifications added, with original box, serviced: was not recording sampling from the internal microphone - and power switch would not turn reliably on - all is repaired now and the unit in perfect working order! (A $150 job!)

Note: The SK-1 is known to have a design flaw (or a limitation, that is due to the technology that was available and used at the time): every time when "Auto power off" kicks in and turns off the power (about 7 minutes of non use) or: when turning the power off manually: then all programming and samples are lost - This is common to all SK-1's - If you want to pay for it, I can look into what can be done to modify it, so that the memory is kept, but as a lot of time will have to go into that, don't expect it to be cheap. I found out that dis-abeling the auto power off function and keeping memory are separate modifications.

Common Casio SK-1 Modifications (NOT INCLUDED (!), but listed here, to show what others do with this synth - I can offer modifications at additional cost)

Pitch and Clock Control

* Variable Pitch / Reclocking Knob: Replaces or alters the main clock circuit (often using an LTC1799 oscillator board) to sweep the pitch up and down, drastically slowing down or speeding up the processor and extending the raw sample playback time. [1, 2, 3]

* Octave Downshift Mod: Uses a clock divider circuit and a multiplexer switch to step the processor clock down, dropping the keyboard notes lower by an octave. [1]

* Pitch Select Toggle: Switches between standard factory pitch and variable pitch mode. [1]

Circuit Bending and Patch Bays

* Audio Patch Bay: Installs 3.5mm or RCA jacks wired directly to the sound ICs and matrix columns to create raw circuit-bent glitches, distortion, and unpredictable audio textures. [1, 2, 3]

* Hardwired FX Switches: Adds toggle switches on the chassis for built-in rhythm stutters, bit-crush effects, and voice-muting glitches. [1]

* Polyphony Drop Switches: Isolates or mutes individual voices from the 4-voice polyphony and drum channels. [1, 2]

Trigger and External Sync

* CV/Gate / One-Key Trigger Input: Wires an NPN transistor (such as a 2N3904) or optocoupler across the "one key play" trigger buttons so an external analog trigger, drum machine, or modular synth (like via an Arturia KeyStep) can step through recorded sequences in time. [1, 2, 3]

* Soft Reset Button: A momentary push-button that drops power to reset the unit without manually pulling the batteries. [1, 2]

Memory and Filter Upgrades

* Sample Memory Expansion: Replaces the stock XRAM chips with upgraded SRAM and controller chips to expand sample capacity beyond the stock single-sample limit. [1]

* Filter and Envelope Mods: Integrates custom analog filters or voltage-controlled filter (VCF) boards before the audio voices are summed. [1]

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-> Purchase Agreement (Please read!): All Sales are: "AS-IS”, FINAL - and: NOT RETURNABLE, NO REFUNDS: LET’s do all that is needed to make sure to get you exactly what you need - BEFORE your purchase! PLEASE ASK QUESTIONS - I am here to assist. All items are used and VINTAGE - sold "AS-IS" (-> vintage = often 45+ years old!!!) and even with the best of refurb / repair work STILL CAN FAIL) and thus is sold without warranty or guarantees of any kind ( -> AS-IS). Your purchase price for this item is for "AS-IS". I aim to perform all work that I foresee necessary, to provide equipment in well and reliably working condition - refurbish in as much detail as possible - and test thoroughly, to gain confidence through testing, to predict that it will last, but cannot guarantee that. Once work complete and the unit is listed here, it is still possible that something be wrong or can go wrong with it (vintage!) - Prices of items offered here reflect the work that went into a given piece of gear until it is listed, but cannot cover what a given piece may need or may need in the future - that would be at your risk and expense - If there are defects, problems or shortcomings: I will be glad to help and likely I can repair, but it will be at additional cost - I do service what I sell at my regular shop rate. Any shipping costs responsibility of the buyer.