The delay that revolutionized modern rock and pop.

Introduced in 1982, the KORG SDD-3000 Digital Delay was popularized by U2 guitarist, The Edge, to forge one of the most identifiable guitar sounds in the history of rock. Far from a one-instrument-pony, however, the SDD-3000 also found a home in early new wave and 80’s synth music. Fully endorsed by KORG, the KORG SDD-3000 Digital Delay plug-in for UAD and Apollo interfaces exactly captures the original unit’s colorful analog circuitry, and burnished-sounding 13-bit delays.

• Tap into the song-inspiring sounds of the legendary KORG SDD-3000 Digital Delay in a fully authenticated plug-in
• Add unique, chewy 13-bit delay, phase, flange, and chorus to guitar, synths, vocals and more
• Get the dynamic interaction of the SDD-3000's analog preamp stage with Unison™ technology for Apollo interfaces
• Use Hold function to layer shimmering pads and soundscapes

Korg SDD-3000

Operational Overview

This section provides a general technical overview of the Korg SDD-3000. For specific details about individual controls, see Korg SDD-3000 Controls.

Features

• Complete circuit model of the famous Korg SDD-3000 Digital Delay used by The Edge, Daniel Lanois, WIlliam Orbit, and more
• Exacting emulation of the analog input and output analog preamp of the Korg SDD-3000 Digital Delay
• Filter circuit for shaping delay repeats
• Comprehensive Waveform and Modulation section for phaser, flanger, chorusing and doubling effects
• Unison technology allows for authentic Hi-Z guitar interaction with Apollo Interfaces
• Sync mode for note value-based DAW tempo sync
• Mono and discrete stereo operation
• The only fully endorsed plug-in of Korg's most sought-after digital delay

Classic 80s Analog Character

With its 1980s-era design, many players have found the Korg SDD-3000 invaluable simply for its boosting abilities and tonal texture, even when the delay circuit is not in use. UA took great care to model the classic analog preamp and support circuitry of the SDD-3000.

Attenuators

The Korg SDD-3000 input ATTENUATOR circuits were originally designed as a way to set the gain staging of the delay to match the level standard of the input signal: -30 dB (Hi-Z instrument), -10 dB (unbalanced/consumer line-level), or +4 dB (balanced/professional line-level). The delay circuit nominally operates at line-level, so when -30 dB is selected, the signal is passed through an additional amplification stage, employing the colorful JRC op-amps that made the SDD-3000 and other classic 80s effects sound so unique.

When a line-level signal is input while in -30 dB mode (or a +4 dB signal is input while in -10 dB mode), additional saturation and "crunch" is introduced, a behavior that is beloved by SDD-3000 aficionados. Trying different ATTENUATOR settings in conjunction with the setting of the LEVEL control can provide a wealth of useful colorations and distortion.

Low-Bitrate Digital Sheen

Today, we may be used to high-quality "colorless" 16 or 24-bit converters in our digital hardware. However, at the time Korg designed the SDD-3000, such converters were either unavailable or too expensive to be practical. This led to the choice of a "12-bit plus one" system, imparting a gritty, organic 13-bit sound that goes far beyond mere repetition. The sample rate-based modulation system further adds to the unique "early digital" character of this classic unit.

Wide-Ranging Delay and Modulation Effects

With a wide range of delay times and a host of filtering and modulation options, the Korg SDD-3000 can produce beautiful phasing, flanging, chorus, doubling, and delay effects. If delay-plus-chorus or another combination effect is your aim, you can stack multiple SDD-3000 instances, without the need to clear additional space in your budget or gear racks.

Unison™ Integration

The Korg SDD-3000 features Unison technology for integration with Hi-Z instrument inputs in Universal Audio Apollo audio interfaces. When the Korg SDD-3000 is placed in the dedicated Unison insert within Apollo's Console application, Apollo's Hi-Z input circuits physically adapt to the Korg delay's input impedance, providing your instrument input signal with the same reactive response and gain staging interaction found in the vintage hardware, providing all the sonic character and loved imperfections of this 80s classic.

Additionally, with Unison gain staging mode, the LEVEL and ATTENUATOR controls can be adjusted using Apollo's hardware controls.

Note: Unison Hi-Z interaction is active only when SDD-3000 is placed in the dedicated Unison insert within Apollo's Console application. For complete details, see Unison.

New Functionality

While the original Korg SDD-3000 hardware had to be cabled up for a mono and dedicated dry out, the UAD Korg SDD-3000 plug-in gives you five output routing options from a drop menu. Plus, you can use a dedicated Position control to place the effect anywhere in the stereo field.

Artist Presets

Presets from prominent Universal Audio artists are included. You can access the artist presets using the UAD preset browser.

Signal Flow

This signal flow diagram was printed on top of the original SDD-3000 rack unit. Although the plug-in does not have external control inputs, its algorithm is faithful to the signal flow of the original hardware.

Korg SDD-3000 signal flow diagram

Korg SDD-3000 advertisement, circa 1982

 

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Korg SDD-3000 Controls

Control Groupings

Associated controls are grouped by processor function. Control descriptions in this article are similarly grouped.

INPUT

This section provides access to the classic Korg SDD-3000 input "attenuator" circuit with its distinctive preamp.

INPUT ATTENUATOR

The stepped input ATTENUATOR helps match the level of signals connected to the SDD-3000 input. The -30 dB setting provides the most gain and is intended for instrument-level signals. The -10 dB and +4 dB settings are intended for line-level signals, with +4 dB providing the least amount of gain. Experimenting with ATTENUATOR settings can provide a range of tonal options.

Note: While the values of the ATTENUATOR switches may seem counter-intuitive, with lower numbers providing more gain, it is faithful to the original hardware circuit.

Apollo Unison Interaction

Gain Stage Mode Control When the plug-in is placed in a preamp channel's dedicated Unison insert within UAD Console and Apollo is in Gain Stage Mode, the input ATTENUATOR is the second gain stage that can be controlled with Apollo's preamp gain knob. When this gain stage is selected in Gain Stage Mode, a yellow rectangle surrounds this control in the plug-in interface (as shown at right), indicating the parameter is available for bidirectional adjustment with the hardware knob and/or the software knob in the plug-in interface. Tip: Press and hold Apollo's preamp gain knob for three seconds to enter or exit Gain Stage Mode. When in Gain Stage Mode, press Apollo's preamp gain knob to cycle through the available gain stages. See Unison for details.

LEVEL

The LEVEL control sets the gain amount for the input preamp that follows the attenuator circuit. Judicious setting of input and output attenuators along with the LEVEL control opens up a range of clean or colored effects. The HEADROOM meter is useful when making these settings, to see how "hard" the signal is hitting the delay circuit.

Apollo Unison Interactions

Default Apollo Control When the plug-in is placed in a preamp channel's dedicated Unison insert within UAD Console, LEVEL can be adjusted with Apollo's preamp gain knob (the hardware control on the interface panel) and/or the software knob in the plug-in interface. This bidirectional interaction is available even when Apollo is not in Gain Stage Mode. Gain Stage Mode Control When Apollo is in Gain Stage Mode, LEVEL is the first gain stage that can be controlled with Apollo's preamp gain knob. When this gain stage is selected in Gain Stage Mode, an orange ring surrounds this control in the plug-in interface (as shown at right), indicating the parameter is available for bidirectional adjustment with the hardware knob and/or the software knob in the plug-in interface.

HEADROOM Meter

The HEADROOM meter displays the signal level present at the input of the delay circuit. This can be useful when setting the input ATTENUATOR and LEVEL controls, to get a sense of whether the delay circuit input is operating within its more linear range (dimly-lit 0 dB or below), or being pushed into saturation or distortion (strongly-lit 0 dB or above).

Note: As with the original hardware, the HEADROOM meter will indicate an overload before the signal actually clips.

MUTE

The MUTE switch, which is not available on the original hardware, mutes the dry signal entering the delay processor, while the wet processor output is still heard. MUTE is active when the switch's LED is lit.

PROGRAMMER

This section contains controls for delay time, effect mode, and host sync.

MODE

The following routing modes are available:

• Mono In/Mono Out – Monophonic input and output.
• Mono In/Stereo "B" +/- Out – Routes the standard wet/dry summed signal to one channel, and the "difference" (out-of-phase mix) of the same signals to the other channel. This can add dramatic stereo imaging effects to mono signals.
• Mono In/Direct L-Effect R – This mode accepts mono signals, and outputs the dry signal on the left channel, and the processed signal on the right channel.
• Mono In/Effect L-Direct R – This mode accepts mono signals, and outputs the processed signal on the left channel, and the dry signal on the right channel.
• Stereo In/Stereo Out– Unique to the plug-in, this mode provides true stereo processing of stereo signals. This option is not possible with the original hardware.

MODE Notes:

• If a stereo signal is input when SDD-3000 is in one of its mono-in modes (1, 2, 3, or 4), only the left input signal is processed.
• When the plug-in is inserted in a mono in/mono out configuration, mode 1 (Mono In/Mono Out) is the only available mode. In this case, the other modes in the drop menu are gray and cannot be selected.

DELAY TIME Display

This LCD display shows the current delay time. When SYNC is inactive, the delay time is displayed in milliseconds. When SYNC is active, the delay time is displayed as a fractional rhythmic subdivision of the host application's current tempo.

The DELAY TIME display can be used to enter delay times and select tempo subdivisions. When SYNC is inactive, click the display to enter delay times directly using text entry. When SYNC is active (when a comma is shown in DELAY TIME display) click the display to view and select available rhythmic subdivision values from a drop menu.

SYNC

When SYNC is enabled, delay times are synchronized to the host's tempo instead of absolute time. SYNC delay times are fractional beat/bar rhythmic subdivision values. Click the SYNC button to toggle the state; SYNC is enabled when a "comma" is shown in the DELAY TIME display.

To adjust the rhythmic division in SYNC mode, use the UP/DOWN buttons, or click the DELAY TIME display to view and select available rhythmic subdivisions from a drop menu, as shown at right.

Note: For complete details about this feature, see the Tempo Synchronization chapter within the UAD System Manual.

DOWN/UP

The DOWN & UP buttons can be used to specify the delay time. When SYNC is disabled, these buttons lower or raise the delay time in milliseconds. When SYNC is enabled, these buttons decrement/increment the available synchronized rhythmic subdivisions.

Tip: Press and hold the DOWN or UP buttons to increase the rate at which the delay times are changed.

REGENERATION

This section offers controls for delay feedback and filtering, as well as delay hold and wet signal inversion for phase effects.

DELAY INVERT (INV)

Enabling this INV option inverts the polarity of the delayed signal. Polarity inversion is active when the switch's LED is lit.

Polarity inversion can create unique "hollow" chorus and flange effects by introducing phase cancellations and interactions.

HOLD

Enabling the HOLD option repeats the entire 1023 ms of content in the delay processor indefinitely, until the HOLD button is pressed again. HOLD is active when the switch's LED is lit.

HOLD can help create creative stuttering, swelling, or ringing effects, depending on the current processor settings. Other controls remain functional when HOLD is active, enabling further manipulation of the delay's memory content.

FEEDBACK

The FEEDBACK knob controls the amount of delayed signal that is fed back into the delay circuit's input. At lower settings, fewer repeats are heard. At higher settings, more repeats are heard. At very high settings, the delay can repeat infinitely, with each repeat "degrading" the signal in a colorful manner over time.

Tip: Enabling the HOLD option provides "infinite" repeats without the cumulative signal coloration caused by high FEEDBACK values.

FILTERS

The four-position LOW and HIGH filter circuits apply to the delayed signal. When set to FLAT, the delayed signal is unaffected. The filters are used to create band-limited delay effects.

LOW – As the switch is moved downward the cutoff frequency is increased, filtering low frequency energy from the delayed signal.

HIGH – As the switch is moved downward the cutoff frequency is decreased, filtering high frequency energy from the delayed signal.

MODULATION

This section contains the waveform, intensity, and speed controls for modulating the delay time.

MODULATION elements

WAVEFORM

The WAVEFORM switch selects the shape of the delay time modulator. The following options are available:

• Triangle – A cyclical up-and-down shape with slanted linear slopes.
• Square – A cyclical up-and-down shape with vertical linear slopes.
• RND (Random) – A randomized motion, derived from a sample-and-hold circuit.

Note: As with the original hardware, FREQUENCY is disabled in RND mode. Although the frequency LED still shows activity in RND mode, the FREQUENCY control doesn't actually do anything.

• ENV (Envelope) – This mode employs an envelope follower on the audio input signal, shifting the delay time according to input signal dynamics.

INTENSITY

The INTENSITY control sets the amount of delay time modulation. Low settings allow for subtle changes over time. Higher settings invite more radical shifts.

FREQUENCY

FREQUENCY sets the rate of delay time modulation. When ENV selected, this control sets the release time of the envelope follower.

Note: FREQUENCY has no effect when WAVEFORM is set to RND.

FREQUENCY LED

The LED to the right of the FREQUENCY control changes its brightness to reflect the current value of the modulation circuit. When the LED brightens, the modulation circuit is in its higher ranges. When the LED dims, the circuit is in its lower ranges.

BALANCE

These controls provide for blending of the original and processed signals, and stereo positioning of the output signals.

BALANCE elements

EFFECT

The EFFECT control sets the mix between processed (wet) and source (dry) signals that appears at the output. At its center position, dry and wet are blended at a 1:1 ratio. As the control is rotated counter-clockwise towards the DIRECT label, the processed signal is decreased, with a 100% dry signal at the end of the range. As the control is rotated clockwise towards the EFFECT label, the processed signal is increased, with a 100% wet at the end of the range.

POSITION

The POSITION control, which is not available on the original hardware, continuously positions the output of the dry/wet blended signal across the stereo field. As the control is rotated counter-clockwise towards the "L" label, the right output channel is attenuated, with only the left signal heard at the end of the range. As the control is rotated clockwise towards the "R" indicator, the left output channel is attenuated, with only the right signal heard at the end of the range.

When the plug-in is used in a mono-in/mono-out configuration, this control is locked in the center position.

Tip: Click the "0" text label to return the POSITION knob to its center position.

OUTPUT

This section provides the final output controls, with the classic Attenuator circuit and a range of utility settings.

OUTPUT elements

BYPASS

BYPASS disables the delay processor while the functions and sonics of the analog circuitry remain active. Bypass is active when the switch's LED is lit.

Tip: If HOLD is active when BYPASS is engaged, the looped phrase retained by the HOLD feature is heard again when BYPASS is disengaged.

OUTPUT ATTENUATOR

The stepped output ATTENUATOR helps match the level of signals connected to the SDD-3000 output. The -20 dB setting provides the most output gain, with +4 dB providing the least amount of output gain. Experimenting with ATTENUATOR settings can provide a range of tonal options.

Note: While the values of the ATTENUATOR switches may seem counter-intuitive, with lower numbers providing more gain, it is faithful to the original hardware circuit.

Apollo Unison Interaction

Gain Stage Mode Control When the plug-in is placed in a preamp channel's dedicated Unison insert within UAD Console and Apollo is in Gain Stage Mode, the output ATTENUATOR is the second gain stage that can be controlled with Apollo's preamp gain knob. When this gain stage is selected in Gain Stage Mode, a green rectangle surrounds this control in the plug-in interface (as shown at right), indicating the parameter is available for bidirectional adjustment with the hardware knob and/or the software knob in the plug-in interface. Tip: Press and hold Apollo's preamp gain knob for three seconds to enter or exit Gain Stage Mode. When in Gain Stage Mode, press Apollo's preamp gain knob to cycle through the available gain stages. See Unison for more details.

OUTPUT INVERT (INV)

Enabling the output INV option inverts the polarity of the processed signal at the output. When used in by itself or in conjunction with the input INV option, a further variety of phase-manipulation effects are possible.

WET SOLO

Enabling WET SOLO mutes the dry signal entirely, mirroring the effect of turning the EFFECT knob fully clockwise to the 100% wet position. WET SOLO is active when the switch's LED is lit.

POWER

Turning POWER off turns off the DISPLAY TIME LCD, disables the SDD-3000 algorithm, unloads the plug-in from the UAD DSP. POWER is useful for comparing the processed sound to the original signal. Pressing POWER a second time re-enables the effect.

Tip: UAD-2 DSP load is reduced when Power is disabled (if UAD-2 DSP LoadLock is disabled in the UAD Meter & Control Panel).

 

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Korg SDD-3000 FAQ

What lengths did UA go to create Korg SDD-3000?

The Korg SDD-3000 delay has been out of production for many years now. And, even if you find one, many of the parts needed to repair and maintain these units are discontinued. Many dedicated fans of this delay have to find broken units just to steal parts from. These are just some of the reason finding a perfectly working unit can be costly and time consuming.

Once we found our "golden unit", a year long process went into uncovering all the analog and digital secrets this sought-after unit had to offer. First was the analog preamp & output section. Filled with JRC-made op-amps (the same type as many classic preamp, boost, and overdrive pedals of that era), the analog section is critical in achieving a pushed "front of amp" sound when used in a guitar rig.

Now comes the AD/DA converters. While many are used to seeing 16-bit or 24-bit converters these days, back then they decided on the more affordable 12-bit plus 1-bit design for an unusual 13-bit delay. Considered low resolution by today's standards, this gave the delay line a more gritty and organic sound. Along with its sample-rate based modulation, this gave the Korg SDD-3000 a sound like no other delay. All of these characteristics were painstakingly measured and reproduced for our plugin.

And with Unison technology, the analog preamp responds to your guitar just like the original hardware!

What is the Korg SDD-3000?

This now vintage rackmounted 80's digital delay became the sound of some of the biggest guitar driven hits of that era. With its instrument friendly analog input and output stage, many artists found it perfect for driving guitar amps to the edge with punch and clarity.

Why does the SDD-3000 matter?

It's all about one major artist, U2. According to Daniel Lanois, the producer for many of U2's biggest recordings, the Edge's rig was simple starting with THE UNFORGETTABLE FIRE:

"It wasn't a complicated rig: just a guitar he liked through a Korg SDD-3000 digital delay into a Vox. Three components, mono - that's it. The great thing about the Korg's is its three-position level switch, which lets you hit the amp with about 10 extra dB. It's more overdriven than if you just plugged the guitar straight into the amp, even when it's on bypass." Guitar Player Magazine – 1993

Next to people like David Gilmour from Pink Floyd, The Edge's sound has been a topic of discussion for many guitar effects devotees. It is the stuff of legend. And next to making the Vox AC-30 cool again for pop/rock music, he made rhythmic delay hooks practically an entire style of playing. Just listen to "Pride - In the Name of Love".

How does Unison work with the SDD-3000?

To enable near-zero latency Unison recording, simply plug your guitar into the Hi-Z input of your Apollo interface, and place the plug-in in the dedicated Unison insert in Apollo's Console application. In addition to physical gain and input impedance control of the Apollo's hardware preamps, Unison allows tactile bidirectional control of the modeled amp parameters. For more information, see Unison.

How do I run the SDD-3000 in stereo?

To take advantage of the SDD-3000's stereo features and sound, insert the plug-in on an aux bus in Apollo's Console, then route the signal to the aux via the input channel's send control. Alternately, you can insert the plug-in on a stereo track in your DAW.

How do Unison preamp plug-ins work with Apollo's built-in preamps?

Apollo's preamplifiers are digitally controlled and offer high-resolution, ultra-transparent translation from input to converter. While fantastic sounding on their own, these preamps are also designed as an ideal starting point to add processing color through Unison-enabled preamp plug-ins. Specifically, Unison preamp plug-ins control the analog impedance and gain structure of the Apollo's physical preamps — so hardware and software works in tandem to very convincingly emulate classic tube and solid state preamp designs.

How do I monitor the SDD-3000 in Apollo's Console, but send only a dry DI signal to the DAW for re-tracking/tone tweaking later?

Simply place the plug-in in any regular (non-Unison) INSERTS slot in Console, and set Console's INSERT EFFECTS function to UAD MON (print dry) instead of UAD REC (print wet).

I own UAD-2 hardware and/or Apollo 16. Can I still use the SDD-3000?

Yes. Unison plug-ins can also be used as standard UAD plug-ins inside your DAW of choice, or for realtime processing in any Apollo Console insert. Unison plug-ins are great for adding color and tone with any UAD-2 hardware, but Unison preamp interactivity is only possible with Apollo interfaces that have physical mic preamps.

Original Korg SDD-3000 hardware unit

All visual and aural references to the SDD-3000 and all use of Korg trademarks are being made with written permission from Korg Inc. Special thanks to Hironori Fukuda, Kei Nakajima, John McCubbery, Shige Kawagoe, Yoshihiro Hashimoto, and Masaki Ono.