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Korg AM8000R

Ambience Multi-effect Processor By Derek Johnson
Published February 1998

Korg AM8000R

This good‑looking unit hides more than just reverb beneath its shiny exterior. Derek Johnson appreciates the ambience...

Following last month's review of Korg's funky new multi‑tap digital delay, it would be easy to assume that its companion processor — the AM8000R ambience multi‑effects processor — would be dedicated to variations on a reverb theme. As it turns out, this is only part of the story. The AM is both more and less than a reverb processor: more because it offers a variety of non‑reverb effects (many of which can help in the creation of ambiences) and less because the actual reverb section is not as sophisticated as one might expect. But we're jumping ahead of ourselves.

Three Into One

Essentially, the AM8000R is a three way multi‑effects unit: it offers two effects blocks (FX1 and FX2) that can each access an identical selection of 29 effects, plus a dedicated delay/reverb effect block with a choice of 11 different treatments. The 29 effects available to FX1 and FX2 are listed in a separate box over the page, but I'll just mention here that alongside the straight ones — various types of delay, chorus, flange and so on — are some interesting processors I wasn't expecting to find. See the 'Sound' section later for details.

The signal path starts with a so‑called Pre‑EQ (high and low frequency with gain and a swept mid), which can be bypassed if you wish. Korg have provided a flexible routing matrix which offers plenty of control over how effects are routed and accessed, but one strange anomaly is that the individual effect blocks can't be removed from an effect chain, although their volume can be set to zero, and they can be muted over MIDI. A number of effects are provided in stereo or dual versions (the dual version provides independent control over parameters for left and right signal paths, while stereo effects have one set of parameters for both); there are also strictly mono and mono‑in/stereo‑out effects. Even the delay/reverb block effects have a similar range of options.

Physically and operationally the AM is virtually identical to the DL: it has the same brushed‑aluminium 1U rackmount package, the same highly visible 12‑digit fluorescent scrolling display, and the same five control knobs and four buttons. But there are minor differences. For example, three of the four small buttons toggle the effects blocks on and off, which is nice for real‑time experimentation, though their 'off' status can't be saved as part of an effect program. The fourth button is a standard bypass switch. Another difference is that the AM8000R's output‑level control is not a dual ganged pot, as found on the delay, meaning that left and right output balance can only be tweaked in software. The AM8000R does, however, retain the dual input‑level control of the DL. The back panel is nearly identical: two sets of stereo ins and outs on quarter‑inch jacks and the standard MIDI socket triumvirate are there, but, unlike on the DL8000, three of the four external control sockets function as inputs for expression pedals. The fourth accommodates a simple bypass footswitch. Power comes from a chunky external PSU.

Editing & MIDI

Although the effects and their actual parameters are obviously different to those in the DL8000, the method of editing patches is identical: turn the Function knob clockwise to scroll through a list of parameters, occasionally press the Function knob to access various sub‑menus, where available, and tweak the Value knob to adjust parameter values. A typical sub‑menu is provided when you want to fine‑tune an effect: the main top‑level parameter allows you to select an effect type (to go in the FX1, FX2 or delay/reverb effect block), and pressing the Function knob takes you to the full parameter list for your chosen effect. To store an edited program, press the Value knob and select a memory location. Just like the DL8000R, the AM offers 256 memory locations: 128 preset and 128 user‑definable.

The AM offers just as comprehensive a selection of real‑time control options as the DL. The Warp! knob once again provides real‑time front‑panel control over parameters in a program, something like the real‑time control knobs that have become so popular on synths lately (pressing it restores a Warped parameter back to its normal setting). In addition to the Warp! knob, three expression pedals and MIDI events (including Note Ons and the full range of controllers) can be used to control up to eight parameters per program. The MIDI controllers are defined globally, and then assigned on a per‑program basis. One nifty feature to keep in mind is that effects can be muted via MIDI. This adds considerably to the processor's value on stage, since by muting effects (or changing sundry parameters with controllers) you can make a single program manage many jobs, during the course of a single song, say.

In Use

My comments about operating the DL8000R go for the AM8000R, and even with the greater number of effects and parameters offered by the AM8000R, editing is just as easy. The most awkward tasks involve working out the various level, pan and routing options for the three available effects. Luckily the operation is so logical that once you've conceptualised what you want to achieve, chances are that the AM8000R will let you do it. For example, I was curious as to whether I could use any of the effects independently of each other, perhaps to emulate the dual processing capabilities of some of the more standard multi‑effects processors on the market. A little thought revealed that this should be possible, and a scroll through the parameters confirmed this. Each effect has three main input options: left and right; left; or right (there are options for feeding the outputs of the effects into each other too). Muting the delay/reverb effect for a moment, I assigned mono in/mono out effects to FX1 and FX2. The outputs of the effects needed to be panned hard left and right, and only fed by one of the main inputs, but I got my result: the left channel processed a signal independently of the right, with no mixing of the two outputs. One effect exits the left output, and the other the right. Adding the delay/reverb does mess this up a little, but you don't have to feed the outputs of FX1 and FX2 into this effect unless you want to: it can be fed direct from the main inputs, independently of the other effects. This way you can balance the delay/reverb effect without compromising your independent processing.

A little planning can go a long way with the AM8000R, and this is just one example of the surprising flexibility offered by what is essentially a simple processor. Negative points are few; while there is a tempo delay available, it can't be clocked to MIDI. You choose the tempo (in bpm), which will allow you to sync delays to a song's tempo, but if it varies by any great amount, the sync will come unstuck. The manual also has a lot in common with that provided with the DL8000R: it's not the clearest I've come across, and lacks basic material such as an overview of the unit and concise descriptions of what every parameter does, and how they interact.


The AM8000R's effects are of uniformly high quality, with comprehensive lists of editing parameters on offer for each. For example, the tape delay effect available to FX1 and FX2 has a 'signal‑to‑noise ratio' parameter which allows you to add plenty of grunge if you want it, and the same effect has a saturation parameter, plus flutter, a simulation of a real‑world tape delay's wow and flutter. Other unexpected effects include compressors, a saturator (kind of an overdrive), resonant filters, dual and stereo ring modulators, and the excellent talking modulator. This last effect is a vowel simulator that seems to be nicked from Korg's Trinity workstation — make your treated sounds appear to talk! Rotary speaker fans will welcome the inclusion of separate horn and rotor effects, and comprehensively specified they are too: plenty of control over speed, acceleration, mic distance and mic spread. These all make interesting additions to the AM8000R's sonic armoury.

I was a little disappointed to discover the lack of a truly sophisticated reverb. I was hoping to find something capable of everyday vocal treatments, but to my ears the reverb is a little coarse for this task. I'll quickly add that the reverb is fine for synth, guitar and other instrumental applications, and that vocals can benefit from combinations of effects, especially during a creative or off‑the‑wall mix. I also thought that more choice in the reverb department could have been offered by a unit dubbed an 'ambience' processor; as it is, of the 11 effects in the delay/reverb effect block, only three are true reverbs (with an early reflection option open to FX1 and FX2).


The AM8000R has turned into one of my favourite effects processors. I love its simplicity, but I also appreciate the quality, variety and accessibility of its effects. The unit's presets do, for once, give you an honest idea of what it might be capable of, and the creative amongst you will have a lot of fun exploring the possibilities. Korg's new baby would be a good choice for the musician with an existing collection of effects, who's in search of something unusual, and the sturdy build and large display may well cause the AM8000R to inhabit space in a gigging musician's rack.

Effects Options

The list of effects available to the FX1 and FX2 blocks, though relatively short, is comprehensive and includes a variety of stereo/dual options, where a dual effect offers independent parameters for left and right signal paths. The difference between stereo and dual effects is indicated by their names, but in the following list I've indicated the mono in/mono out effects with an (M), and mono in/stereo out effects with an (M/S).

  • Stereo Chorus/Flanger
  • Dual Chorus/Flanger
  • Modulation Delay (M)
  • Stereo Modulation Delay
  • Dual Modulation Delay
  • Tape Delay (M)
  • Phaser (M)
  • Stereo Phaser
  • Dual Phaser
  • Pitch Shifter (M)
  • Ensemble (M/S)
  • Doppler (M/S)
  • Horn Simulator (M/S)
  • Rotor Simulator (M/S)
  • Stereo Tremolo
  • Stereo Ring Modulator
  • Dual Ring Modulator
  • Stereo Resonance Filter
  • Dual Resonance Filter
  • Stereo Wah
  • Talking Modulator (M)
  • Stereo Compressor/Limiter
  • Dual Compressor/Limiter
  • Stereo Gate
  • Dual Gate
  • Early Reflection (M)
  • Saturator (M)
  • Stereo 3‑band EQ
  • Stereo Ducker


The third processor, dedicated to reverb and delay, offers the following choices:

  • Long Delay (M)
  • Tempo Delay (M)
  • Stereo Delay
  • Dual Delay
  • Cross Delay
  • Left/Centre/Right Delay (M/S)
  • Multi‑tap Delay (M/S)
  • Dual Multi‑tap Delay
  • Room Reverb (M/S)
  • Hall Reverb (M/S)
  • Plate Reverb (M/S)


  • Easy to operate.
  • Very flexible.
  • Great sound.


  • Range and quality of reverbs could be better.
  • Patchy manual.


Like its companion DL8000R delay, this wouldn't be your first or only processor, but if you already have your bread and butter effects needs covered, the AM8000R will add some wonderful sonic jam!