There had been a handful of digital delays around by the time the Korg SDD-3000 was released in 1982, including the Deltalab DL-2, Lexicon PCM 41, Roland SDE-2000 which was hugely successful with guitarists of the time, and of course the very highly regarded AMS DMX 15-80. While the AMS, Lexicon and Deltalab delays were aimed at the bigger studios, companies like Roland and then Korg set about providing digital delays for the common man. Thus, the Korg SDD-3000 digital delay was born.
The Korg was and is, a pretty exceptional device particularly for it’s time. It featured a 17kHz bandwidth and a delay time variable between 0 and 1023ms. (1.23 seconds) It also offered user programmable presets each storing nine parameters, with simple one touch recall. The Korg SDD-3000 also had an inbuilt modulator with four switchable wave shapes which included a random option. An envelope follower and external control voltage input could be used to directly vary the delay time. For live performance, foot switches could control bypass and hold modes, as well as delay time up and down. This is what helped the Korg SDD-3000 found a home in guitarists rigs the world over.
Korg SDD-3000 Controls
The Korg SDD-3000 offers a good clean control layout, featuring five rotary dials for input level (for front and rear inputs) feedback (regeneration), modulation intensity and frequency, as well as output mix to blend the direct and effected signals. The input also features a switchable attenuator to provide -30dB, -10dB or +4dB settings which allow the SDD-3000 to fit into any environment, be it a studio or on stage.
The front panel has a clearly visibly input level meter with resolution typical of the day, as well as a very easy to read LED display for the program number and delay time, which once again is very easy to read even form a distance. The regeneration section also provides switchable filtering, both low and high. The low cut filter can be set to 125Hz, 250Hz or 500Hz giving -3dB per octave roll-off to each regeneration, and the high cut filter can be set to 8kHz, 4kHz or 2kHz cutting -6dB per octave. Lastly, a phase inversion switch is provided, and in combination with the filtering options, allows the Korg SDD-3000 to create some pretty interesting effects.
The modulation section provides switchable waveforms, with a four-way switch offering triangle, square and a rather unusual random wave which works like a sample and hold effect that is clocked by the frequency rate. The triangle wave is well suited for your typical chorus and flanging duties, while the square wave is capable of producing echo/pitch shift effects and the random option simulates ADT. A red LED next to the Frequency control flashes to provide a visual cue to the modulation frequency.
Further effects are created by using the external delay modulation input on the back of the unit. By varying the input voltage, you can vary the delay rate: high voltage, low delay rate, low voltage, high delay rate etc.
Programming the Korg SDD-3000
The Korg SDD-3000 can only store nine programs, lame by todays standards, but this was 1982 remember. All controls on the front panel are remembered, with the exception of the input and output settings. The four pushbuttons beneath the large LED display are used to store and recall each of the nine programs: Write (red), Program (yellow) and Delay time up/down (white).
The nine programs can be stepped through in ascending order, by simply pressing the Program button continuously. When the Program button is pressed while the Write button is held down, all the front panel settings is stored in the program number memory, presently selected, overwriting any previous settings.
Starting with build quality, it has to be said the Korg SDD-3000 is a very solidly built unit with all metal construction, and all the controls feel of high quality. This quality extends to the internals of the unit too, with the rear sockets all mounted to a separate circuit board, and connected to the main circuit board via flexible modular connectors
In use, the Korg SDD-3000 is a pleasure to use, in fact it is a lesson in user interface design that many others could have learnt from. Back in the day, one could have perhaps complained about the imperfect sound quality compared to the original input signal, but it is this exact thing that endears it to us today. I doubt Korg ever expected to create such a legendary delay unit when they first conceived the SDD-3000, but that is exactly what they did.