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Korg SDD1000 Digital Delay

Korg have realised that there is a growing need for delay units that offer the facility of being able to store short samples of sound which may then be replayed by means of a sync pulse. The SDD-1000 offers this facility in addition to the more usual DDL effects and it is priced in such a way as to make it a direct competitor to the Boss DE200.

It has now become common practice to build DDLs in 1U high (1¾") rack cases but Korg have taken the unprecedented step of not printing a block diagram on the top cover!

The black and white photograph may lead you to believe that the styling owes something to the latest Yamaha effects range, but what you can't see is that Korg have thrown subtlety to the wind and printed the front panel legend in screaming canary yellow to match the knob caps.

As you would expect from Korg, the construction is to a very high standard, but as there is a limited amount that one can say about a rectangular steel box, I'll move on.


Again my job is made easier by the front panel layout so kindly provided by Korg in their manual and reproduced here, so I won't insult your intelligence by telling you where the power switch is located, how to operate it, or what the red LED above it means. (For those who can't work this out, write to me at the editorial address and your enquiries will be treated in the strictest confidence.) Zooming over to the left, we find the input level control and a four section LED ladder-style meter which is essential on this kind of equipment. The single clip LED used by some other manufacturers is not really satisfactory if optimum performance is going to be maintained.

There is no delay time readout as such but a six position switch gets you into the right ballpark. This value may then be further modified by the 'Factor' control which is really a fine tune delay function. For the longest delay of 2048ms, you obviously have to use Max Factor.

As all connoisseurs of time devices will know, the section labelled 'Regeneration' is nothing to do with replacing one fed-up Dr Who actor with another, it is of course feedback, used for creating multiple echoes or flanging effects. Feedback on the SDD-1000 may be applied either in phase or in anti-phase which is useful at very short delay times, and a continuously variable 24dB/octave hi-cut filter acting on signals around 10kHz allows further modification of the fed back signal.

In the modulation department, the intensity and frequency controls are standard issue, but it is worth mentioning that the modulation range is 4:1 - deep enough to produce reasonable flanging. Rather than opt for a balance control to adjust the relative dry/delay signal mix, separate volume controls are provided for both the dry and the delayed output. The next section is the sync section and it is this that is of real interest if you are considering the Korg for its sampling abilities.


There are four modes of operation and these are selected by means of the four position slider switch. In the 'off' position, the unit functions as a standard digital delay but the other settings are all sampling modes which work at the 1024 or 2048 millisecond delay settings giving a maximum sampling time of a little over two seconds.

In the 'Sequencer' mode, the unit is capable of sampling a sound or musical phrase after which it automatically enters its replay mode and then repeats the phrase indefinitely until it is stopped either by pressing the bypass switch (or a suitable footswitch connected to the remote bypass socket) or by pressing the 'Record' button.

Next comes the 'Sampling' mode and here, operation is very much like the Boss DE200 where the Record button or a trigger footswitch is used to start the recording process. The stored sound can then be retriggered by means of a footswitch or by a pulse from a drum machine trigger output (S trigger type).

The third mode of operation is the 'Trig Overdub' setting which in effect allows you to synchronise repeat echoes to the music, again using a footswitch or external trigger pulses. On the next section comes the 'Hold' button which as expected, freezes any sound stored in memory and recirculates it indefinitely.

Socket To 'em

The rear panel sports an input level selector switch adjacent to the input socket and three outputs are provided, a direct out, a mix out, and a mix out with the delayed component inverted in phase.

Moving along, we find no less than five footswitch sockets labelled as follows: 'Trig In', 'Rec', 'Hold', 'Rec Cancel' and 'Bypass', all of which permit remote control of their front panel counterparts either by switches or S trigger inputs.

The impressive dynamic range is achieved by using 12 bit resolution in addition to pre-emphasis/de-emphasis and a companding noise reduction system. A 10kHz bandwidth is maintained up to delay times of 1024ms but above this, things deteriorate to a miserly 5kHz. This is, however, a useful option and the 5kHz bandwidth setting doesn't sound too dull when used with electric guitar or any other sound source that doesn't contain too much in the way of rich high frequency harmonics.

In Use

Checking out the straight delay effects first, I was impressed by the lack of quantisation noise and when I set up a flanging effect (shortest delay range with bags of feedback), the result was satisfyingly strong. In this mode, the negative feedback option gives a hollow, almost resonant phaser - type of colouration to the effect and this alternative is well worth having.

Using positive feedback, the effect is more like that produced by analogue flanger pedals ie. deep, but more conventional sounding.

It was also very easy to set up first rate chorus effects but I understand that Korg are using a triangle wave for the LFO modulation where a sine wave might sound just that little bit more natural.

Moving on to the sampling effects, these work in a straightforward way as described, but as with the Boss DE200 delay, the sampling process is synchronised by means of a footswitch; a sound activated trigger would make this task so much more precise.

The sound trigger project described in HSR (November/December 84) could be adapted for this purpose but Korg have made things awkward by sticking to their S trigger format on all external trigger inputs. This does mean that an S trigger pulse or a footswitch will work equally well in the same socket but, as most other devices including Roland use positive trigger pulses, you will need an S trigger converter (see HSR Classifieds).

This mode of sampling is particularly suited to percussive sounds and in this way, the stored sound may be triggered by a drum machine trigger output pulse (via an S trigger converter) to form part of a rhythm pattern, for example.


This particular mode of operation is best suited to live performance where a note or phrase may be stored and then instantly recycled to form a backing over which the musician can continue to play. I can't see much use for this function in the context of recording but it's there if you need it and it's always easier to ignore a control that exists than it is to use a control that doesn't.


In terms of creativity in a recording situation, this facility really comes into its own, as again, in conjunction with a drum machine trigger output, the echoes of any instrument may be programmed to fall on whichever beat is deemed artistically suitable. This gives a very tight, modern effect as exemplified by a well-known producer's records, but I promised not to mention Trevor Horn in this review, so I won't!


Well, in spite of the colour scheme (it looks OK in very dark studios), the SDD-1000 produces all the standard delay effects with clarity, and even the 5kHz bandwidth setting isn't too unsatisfactory by any means.

I was particularly impressed by the chorus and flanging effects obtained from the Korg unit, which are often disappointing on digital units whilst the sync/sample facilities offer a lot of scope for those musicians who make extensive use of drum machines and sequencers in the course of their recording.

Korg's insistence on sticking to their S trigger system makes interfacing very inconvenient if you aren't using a Korg drum machine and that does mean that you'll have to make or buy at least one S trigger converter to get the best out of this machine.

In most respects then, a high quality device offering a lot of flexibility at a very reasonable price.

The Korg SDD-1000 retails at £375 inclusive of VAT. Details from UK distributors Rose-Morris & Co. (Contact Details).


Input level: -10, -30, -50dBm
Output level: -10, -30, -50dBm
Freq. response
(up to 1024ms): 30Hz-10kHz
(2048ms): 30Hz-5kHz
Dynamic range (effect): 90dB
S/N ratio (effect): 80dB
LFO (triangle wave) frequency: 0.1 Hz-10Hz
Dimensions: 44(H) x 482(W) x 302(D) mm

Previous Article in this issue

Marantz CP430 Stereo Cassette Recorder

Next article in this issue

A&R Arcam One Monitors

Home & Studio Recording - Copyright: Music Maker Publications (UK), Future Publishing.


Home & Studio Recording - Feb 1985

Donated & scanned by: Mike Gorman

Gear in this article:

Studio FX > Korg > SDD-1000

Gear Tags:


Review by Paul White

Previous article in this issue:

> Marantz CP430 Stereo Cassett...

Next article in this issue:

> A&R Arcam One Monitors

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