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The Hot 100

Yamaha EMP100 Multi-Effects Processor

The latest addition to Yamahas highly affordable 100 series, the EMP100, could prove to be its best buy yet. Paul Ireson explains why.

Yamaha's 100 series has produced a range of goodies that offer excellent value in the home recording market, but perhaps none quite so good as the latest addition to the ranks, the EMP100 multieffects unit. The 'multi' isn't quite as, er, multi as on more expensive machines — the combination effects only use two effects at a time — but the audio quality is outstanding at the price, and it still performs most of the processing tricks that you'll need for keyboards in a bedroom studio, and indeed many of the tricks (apart from compression and distortion) that you'll need for, say, vocals and guitar — including pitch shift.


The unit has 150 effects Programs — 100 presets and 50 locations for user effects. In order to allow MIDI selection of all Programs, a Program Map function is available. There is a single map, and you can set the unit to receive on any single channel, to respond to program change messages on all channels (omni mode) or to ignore all such messages. There is no real time MIDI parameter control.

The half-rack unit will look a little familiar to anyone with an FX500. The dimensions of the two processors are identical, presumably because they're built into the same chassis, and there's the same large rotary input level control on the left of the front panel. The back panel connections are also the same — mono input, stereo outputs with -20/-10dB level switch, MIDI In, and two footswitch sockets — although one of the footpedal sockets has changed function. On the FX500 you have Bypass and Program Inc/dec; on the EMP100 it's Bypass and Tap Tempo.


Eight buttons provide for programming and controlling the EMP100: a pair of Inc/Dec buttons; Program Recall; Memory; Param; Store; MIDI; Bypass. A selection of LEDs provides your window into the machine. Signal and Peak indicators, next to the Input Level control, help you set an optimum input level. Above the buttons you'll find a set of eight Effect/Parameter indicator LEDs, and to their left another five parameter indicators. To the left of these is a 3-digit LED display, and to their right a Bypass LED and a pair of LEDs which are dedicated to helping you program the Program Map.

The Inc/Dec buttons scroll through memory locations in memory mode (selected by — you guessed it — the Memory button) and you can select the Program number indicated on the 3-digit display by pressing Recall. The number flashes until you do so, to indicate that the number on the display is not that of the current Program. If you want to edit the current Program, pressing parameter takes you to edit mode, and subsequent presses of the button cycle through the parameters available in the algorithm on which the current Program is based. You change parameter values, shown on the display, with the Inc/Dec buttons, and if, you want to keep what you've created, you can store the new effect to one of the 50 user Program locations. Note that there's no way to change algorithms in a Program — when creating Programs, you have to select as a starting point a preset Program that contains the algorithm that you want.


Editing Programs is the one aspect of using the EMP100 that I didn't enjoy — trying out all of the preset Programs on a range of material provided hours of fun, but the user interface is pretty lousy. The problem is that the only way of telling which parameter you have selected is by referring to the combination of two sets of LEDs — the eight above the control buttons, and the five to their left. If the abbreviations on the LEDs aren't enough to tell you what parameter is selected (a chart on the top of the unit helps, listing what parameters are available for each algorithm), you'll have to refer to the manual to find out what you're editing.

This is guaranteed to drive you mad for as long as it takes to get to know the EMP100 pretty well, which means that many users — most, I suspect — will never go any further than changing delay times to match tempo, and that can be achieved with the tap tempo footswitch. Of course, this may well be true of most multi-effects units these days. Does anyone know how many people program their rack effects?


The rest of the news on the EMP100 is good, however. The 14 algorithms offer a range of single and combination effects: Stereo Pitch (shift); Triple Pitch (shift); Chorus; Flange; Symphonic; Delay; Early Reflection; Reverb; Stereo Pitch + Reverb (in parallel); Stereo Pitch -> Reverb (in series); Symphonic + Reverb (in parallel); Delay + Reverb (in parallel); Delay -> ER (in series); Chorus -> Delay (in series).

The effect/dry balance parameter, the only parameter found in all algorithms, is set to 100% effect for all Programs except those intended for guitar and bass processing, on the assumption that guitarists will plug straight into the EMP100, and everyone else will use it in an effect loop. As you'd expect, the combination effects make some compromises, such as reducing the maximum delay time from 740ms (stereo delay) to 300ms (Delay + Reverb).

The quality of all effects lives up to the promise of the CD-standard 16-bit 44.1 kHz sampling, and the 100 presets show off the capabilities of the unit to good effect. Flipping through them one by one, I was genuinely surprised by the EMP100's clarity and fidelity. They are arranged in sections which Yamaha suggest are suitable for keyboards, general use, guitar, vocals etc., and a full listing on a pull-out card in the manual helps you find you way around, with a brief description of each effect.


The provision of pitch shifting is a surprise, and a very welcome one, on a unit in this price range — I think this makes the EMP100 the cheapest unit to offer the effect. The Stereo Pitch produces two shifted notes, and the Triple Pitch three. The effect works best when used to create subtle doubling or detuned effects, or to produce outrageous rising/falling effects via the feedback and delay facility on the stereo shift. You can even create mini-rhythms within such an effect, as the left and right channels have separate delay times.

Both Stereo Pitch and Triple Pitch allow the interval of each shifted note to be defined in coarse and fine parameters up to an octave up or down from the root, but this is no studio harmoniser — don't expect to extend your vocal range by an octave. The practical shift range, before the pure shifted sound becomes noticeably artificial, is about 3 semitones down or 4 up, for vocals or snatches of music (which is what most people will want to treat in this way). Beyond this range, the shift is useful as an artificial effect (robotic voices etc.) rather than a natural one.

The chorus is a fine, rich effect, and you can apply both amplitude and pitch modulation. The flanging is also smooth, and even at extreme depth and feedback settings the result is a strong, useable effect rather than a harsh metallic one. Symphonic is a rather gentler treatment than chorus, which sounds fabulous on strings.

The stereo delay offers up to 740ms on both channels, and it's here more than on any of the other effects that the audio quality of the EMP100 shows through. With the feedback turned right down, I found it very hard to distinguish an original signal from an echo.

The tap tempo function allows you to change delay times to match an echo rhythm to the tempo of a song simply by tapping a footswitch twice, in time with the music. The left channel delay time is is set directly, and the right channel delay is changed to preserve the original ratio of the two delay times.

The Early Reflection and Reverb algorithms both offer several types of effect: Hall, Random, Reverse, Plate and Spring for Early Reflections: Hall, Room, Vocal and Plate for Reverb. Both effects sound good and clean, although the EMP100 can't manage the depth and complexity of more expensive processors.

The combination effects offer six algorithms which feed pitch shift, chorus, symphonic or delay into reverb or early reflection. Three are parallel processing algorithms and three use serial processing.

The only problem with the combination effects is that they tend to have more parameters to edit — all but one have eight to play with, in fact — which takes us right to the heart of the user interface problem. Listening to the effects is fine — re-programming them is another matter entirely.


I think the EMP100 will prove to be a big seller. It is hardly an all-singing all-dancing processor, but its quality, the range of basic effects on offer, and the pitch shift capability make it excellent value for money. Whilst it will be most popular as a companion to cassette multitrackers and in small MIDI studios, it could be equally useful in a larger, more professional setup as a handy extra processor. If you run a lot of instruments live it's always good to have another effects unit around. The rather tiresome programming procedure lets the unit down, but overall the EMP100 offers the user more than enough to make it an excellent buy.


£259 Inc VAT.

Yamaha-Kemble Music UK, (Contact Details).


Frequency Response: 20Hz-20kHz
Dynamic Range: >85dB, effect off
THD: <0.1% @1kHz, maximum level.
Sockets: Mono input, Stereo outputs with -20/-10dB switch
Bypass f/s
Tap tempo f/s
Input Impedance: >500kOhms
Output Impedance: 1kOhm
Sample Resolution: 16-bit
Sample rate: 44.1kHz
Memory: 100 ROM programs
50 RAM programs
Effects: Stereo Pitch
Triple Pitch
Early Reflection
Stereo Pitch + Reverb
Stereo Pitch -> Reverb
Symphonic + Reverb
Delay + Reverb
Delay -> ER
Chorus -> Delay

Previous Article in this issue

Jon Hassell

Next article in this issue

The Max Factor

Sound On Sound - Copyright: SOS Publications Ltd.
The contents of this magazine are re-published here with the kind permission of SOS Publications Ltd.


Sound On Sound - Jul 1991

Gear in this article:

Studio FX > Yamaha > EMP100

Gear Tags:

Digital FX

Review by Paul Ireson

Previous article in this issue:

> Jon Hassell

Next article in this issue:

> The Max Factor

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