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Killer Kurzweil

Kurzweil K2000

Kurzweil's new keyboard offers genuine innovation: versatile synthesis, an unparalleled user interface, and up to 64MB of user sampling are only the start of what sets the K2000 apart from other sample-based instruments. Craig Anderton explains why it will turn the head of even the most jaded technophile.

I never thought the day would come when 3,500 words would be nowhere near enough to review a synthesizer, but that was before I was assigned the Kurzweil 2000. As a result, well concentrate on what makes the K2000 different from other machines rather than cover standard features. Granted that technology is giving us one miracle after another, but the K2000 can turn the head of even the most jaded technophile — it certainly turned mine. Here's why.


Trying out the presets gives an inkling as to what's going on. Some sounds are very realistic, others are analogue-like and hark back to the '60s, while others are more like wave sequenced sounds that evolve over time in very sophisticated ways. If you play the keyboard percussively, you'll miss out on some great effects — be sure to hold your fingers down on the keys when checking out Programs and you'll find some surprises. Pressure and mod wheel do something useful in virtually all the Programs (as do the pedal and controller slider); additional Programs are supplied on disk once you've checked out the ROM presets.


The K2000 uses the sample + synthesis approach in sound generation. The simplest unit of sound generation is the Sample. Individual Samples can be edited, then assigned to specific velocity ranges and keys on the keyboard to form Keymaps. Keymaps are then processed through an Algorithm, which includes familiar synthesis modules such as filters and envelopes, and esoteric ones such as non-linear waveshapers. Up to three layers of Keymaps can be layered or split (up to 32 layers for drum Programs), resulting in a Program (if all three layers are in use, the Program will be limited to 8-voice polyphony). Up to three Programs can be assigned to zones in a Setup, with each zone having its own Program (Programs can be layered or split), MIDI channel, and controller assignments. Kurzweil refer to Samples, Keymaps, Programs, and Setups as 'objects'. Other objects include Quick Access banks (described below), sequenced songs, effects, velocity and pressure maps, alternate tuning tables, and a master parameter table. Each object can be saved, deleted, named, and edited and has its own ID number; this may sound confusing at first, but is not unlike other synthesizers — a Program, multi, etc. could also be thought of as having a unique ID, namely, the Program or multi number.


The highest level of the user interface is mode selection, and you can select any of eight modes by pressing the appropriate button. There are three modes for Program access: Program; Setup; and Quick Access.

Program Mode calls up individual RAM or ROM Programs via the alpha dial, up/down buttons, or the numeric keypad. This is all straightforward, except that pressing the up arrow selects the next lower-numbered Program — this takes a little getting used to.

Figure 1. Program Mode screen.

The main Program screen (see Figure 1) shows a scrollable list of all Programs toward the right, the Keymap(s) included in the Program (along with a line under the name that correlates to how much of the keyboard the particular keymap covers), and a few oft-used parameters (octave transpose, all notes off/all controllers zeroed, and MIDI channel). In Figure 1, 'Rockin' Lead' is selected. You can also toggle over to a different Program view screen that replaces the Program list and Keymap information with a very large type version of the Program name (I can even read it without my glasses).

While in Program edit mode, you can enter the Keymap editor and from there enter the Sample editor to edit parameters of individual Samples (loop points, sample start and end, pitch, etc).

As with all the screens, there are six soft buttons keyed to labels on the display. For example, if you press the button under 'Octave' the sound is transposed down an octave.

Setup mode lets you choose Setups. The display and parameters are similar to the Program screen, but instead of Keymap info, there's data on which Programs are in use, their MIDI channels, and how much of the keyboard they cover.

Quick Access calls up a bank of 10 Programs or Setups (up to 100 banks; the first six are in ROM). The idea is that you can group frequently-used patches, such as orchestral, rock, Programs used in a particular song, etc. Again, the display and adjustable parameters are similar to the Program screen. The display lays out the Programs to correlate to the numeric keypad, so any Program is only one button press away.

The five other modes are Effects (for editing and choosing effects), MIDI (for editing MIDI parameters, including multi-timbral operation for sequencing), Master (sets global parameters such as master tuning, intonation, velocity and pressure sensitivity, output assignments, etc.), Song (accesses the scratchpad sequencer), and Disk (for floppy and SCSI peripheral operations).


One test of a synth's friendliness is to see how far one can get without reading the manual, and in this case, I got pretty far — not just Program selection, but as far as disk operations and even editing.

The K2000 follows the by-now-familiar protocol of organising parameters on pages; cursor buttons choose the parameter to be edited, whose value you then change with the detented alpha dial, +/- buttons, and numeric keypad. An Exit button takes you back to square one without having to go through any elaborate 'backup' procedures.

However, there are a number of very cool shortcuts. Suppose you're assigning a particular modulation source to a parameter. If that source is highlighted and you press the Edit button, you'll be transported to the edit page that lets you alter the modulation source's parameters. Furthermore, when editing, the eight mode buttons change identity to do tasks like mark Program pages, mute layers, etc.

Many of the parameter values can also be selected with physical devices — keyrange by pressing keyboard keys, mod wheel values by holding Enter and moving the mod wheel. Another nice touch is that the controller slider can be used as a data slider if you're holding Enter.

There's even a search function. To find all the guitars in a list of Programs, you can type 'guitar' and find each occurrence. And that's not all: parameters are presented in meaningful, musical terms. The filter cutoff is given in Hertz, not as something like 00-99. Velocity trigger points range from ppp-fff, and times are given in seconds and milliseconds instead of arbitrary numbers. For programmers, this is such an incredible relief after years of dealing with synthesizers that don't give you the slightest clue about what you're really doing. Hopefully the K2000 will embarrass other manufacturers into not taking the easy way out, but instead, calibrating their instruments to the real world. Enough said.

The more you work with the K2000, the faster you get. But you don't have to use the shortcuts, which makes it easier for beginners trying to grope their way around the machine. Simply stated, the K2000's operating system sets a new standard for synthesizers and is a quantum improvement over anything that has come before — period. The manual (written by Mark Avenmarg) is excellent, too; it's conversational, well-organised, and thorough. I'm extremely impressed that something this complex can be made so easy to use, and Kurzweil deserves serious accolades for the work that went into making this instrument as accessible as it is.

There is also a training video. While it avoids being patronising or overly cute (the main banes of video manuals), trying to see what's on the LCD — even with a computer monitor, not a TV — is impossible. I'd give the video good marks for effort, but the printed manual is what does the job.


Figure 2. Audio signal path in Algorithm 15.

Each Algorithm consists of several DSP software modules (see box) that process a sample as it works its way to the audio output. There are 31 Algorithms, displayed as block diagrams on the LCD (see Figure 2, which shows the signal flow for Algorithm 15). Some Algorithms are simple: Algorithm 1 offers sample pitch processing, equalisation, and a final amplifier, as well as five control inputs (one for pitch, three for EQ, and one for the final amp). Other Algorithms include five stages of processing, and/or split the signal down two different paths. Some blocks, like pitch and amp, cannot be varied. However, for Algorithm 1, the EQ block could be any of several filter structures: high frequency 'stimulator'; parametric EQ; steep resonant bass filter; 4-pole low-pass; 4-pole hi-pass; twin peaks bandpass; and double notch. It's great to see filtering integrated so completely into the signal path rather than just being a global parameter in an effect. In fact, the K2000 shows a lot of 'modular synthesis' thinking — clearly, many of the designers were working with synthesizers back in the days of patch cords, and didn't forget what they learned.


Each Algorithm block has its own edit page, each of which has several parameters in common: modulation start point, key tracking and velocity, and two modulation sources. The first source has adjustable depth; the second has a variable minimum and maximum depth, and the overall depth can be controlled by another control source. Blocks that have more than one control input include additional pages for those inputs; for example, in algorithm 2, the 'filter' block has two control inputs, one for frequency and one for resonance. Each input has its own set of adjustable parameters.

As has been obvious ever since the days of the Oberheim Xpander, it's the modulation options — rather than, say, the waveforms — that make synthesizers come alive, and the K2000 is well-endowed with modulation sources. Listing and describing them all would take 10 pages (at least, that's what it takes in the manual). As expected, there are all the usual MIDI control sources (pressure, mod wheel, sustain, and so on). More interesting are such options as: control signals that follow incoming MIDI clock signals (synchro-sonic processing lives!); sawtooth waves that rise with each MIDI clock beat; random control signals; triggers that only happen above certain velocity levels; attack/sustain/release envelopes; 'FUNs' (short for 'functions' — these are essentially transfer functions that combine two control signals and perform a mathematical mutation on the combination, and in a very basic way resemble the tracking generators in the Oberheim Xpander); LFO (with 14 different waveshapes); a control source that follows the LFO phase; loop state (turns on when the currently playing sample reaches its loop start point); sample playback rate; several constant values (used for assigning control inputs to FUNs); and a whole lot more.

The modulation capabilities are so extensive that it's easy to Program sounds that evolve in complicated, interesting ways over time. One of the bonus Programs on disk, for example, starts off as a violin patch then mutates into birds. Many other patches sound like a more fluid version of wave sequencing, where multiple sounds melt into each other, grow, and change. To me, this is the K2000's strongest suit, and represents a serious effort to overcome the limitations of sample + synthesis machines. It's no longer a given that your sound has to become static as soon as it hits the loop point.


The effects processor is global, but each Program and Setup can have their own effects settings. The wet/dry mix and two parameters per effect can be modulated; there are 47 preset effects, but you can create up to 80 of your own based on 26 effects algorithms. As with most synths that have onboard effects, you have to specify a particular mode, to determine whether each new Program or Setup calls up an associated effect, or whether the chosen effect works as a master effect on whatever you call up.

Each effects algorithm has the type of parameters you'd expect from a typical outboard effects unit; for example, the Ultimate Reverb has 11 different parameters, with decay time up to 99 seconds. The quality of the effects is excellent, rivalling that of quality outboard devices.


As with effects, MIDI operation is fairly standardised these days. Notable differences include Bank Select to supplement traditional program changes, your choice of 17 velocity and pressure curves that affect only performance data to the MIDI Out (ie. these can be different from the K2000's internal response), the same choice of curves when driving the K2000 from other keyboards (both sets of curves are editable), data filters for both transmission and reception of MIDI data, and of course, multi-mode setup options for sequencing, with several different parameter settings for each channel (output pair assignment, gain, Program selection, pan, volume, etc.).


The K2000 memory has 10 banks. Bank 1 stores objects with IDs of 00-99, Bank 2 objects with IDs of 100-199, etc. These can be different objects; the only important point here is the ID number. However, you may not be able to put 100 objects in a bank, depending on how much memory they take up.

The reason why banks are important is because they are saved to disk as individual files. Therefore you'd probably want to organise related groups of objects — Programs, Quick Access banks, effects, etc. — in the same bank. Banks can be recalled individually, and placed into other banks (eg., bank 2 could be loaded from disk into bank 5; objects are renumbered automatically). You can also save all banks if desired.

You have several options when loading objects. They can wipe out the existing bank and overwrite new data, merge with the existing bank (objects will overwrite like-numbered objects in memory), or append (objects will be reassigned ID numbers to fill in any spaces between existing objects). The disk operation software is very considerate, and shows you what's being loaded (or deleted, if objects are being overwritten). Unfortunately, load-while-play is not supported.

The floppy disk drive handles 3.5-inch 720K or 1.44MB high-density disks; both disk capacities are MS-DOS formats. If you attempt to save a bank that takes up more space than can be held by a single disk, the K2000 will prompt you to save a multiple disk set. Data from either K2000 disk format can be read onto a Mac fixed or removable hard disk by using Apple File Exchange, then read back into the Kurzweil — handy if you want to archive files but don't have a PC or SCSI device for the K2000. I must applaud manufacturers for supporting the MS-DOS format; with one disk, I can keep samples and programs for my Peavey DPM3, banks from the Kurzweil, and text files for documentation of what's on the disk, and even pull the files over to an Atari for archiving if necessary. Furthermore, and very significantly, the K2000 can load samples from Akai S1000 disks, which means access to a huge range of first-class sampled sounds.

What about SCSI? The K2000 formatted, saved, and loaded using an ancient Jasmine hard disk without problems. Just remember to set your IDs correctly and use proper termination protocols (the K2000 is internally terminated), and all should be well.

An upgrade is scheduled for later this year that adds up to 16MB of additional sounds, in 8MB increments. Also planned is a stereo sampling option, and you can fit up to 64MB of sample RAM; that means a lot of sounds. However, the sample RAM is volatile, so you'll need to load sounds in from disk (or from MIDI, if you have lots of time on your hands) each time you need them — one of the best arguments I can think of for factoring the cost of a hard disk in with your K2000.


The K2000 doesn't have a sequencer in the traditional sense, but it does have a RAM scratchpad for recording what you play on the keyboard, or for recording multi-timbral sequences via MIDI, or loading type 0 MIDI files from MS-DOS disks (the filename extension must be .KRZ). Controls are limited; you can change the tempo, and loop a song, or play back all songs in RAM in series (first one song, then the next highest-numbered song, then the next highest-numbered song, etc.).


The sampling option, scheduled for introduction in the 2nd quarter of 1992, will allow for AES/EBU and SPDIF interfacing (just the thing for recording directly to digital recorders such as ADAT). And did I mention that the 17 different alternate tuning scales are editable? Although you can't set these for more than 12 notes per octave, you can create equal tempered scales with more than 12 notes per octave using the Keymap editor.

But we have to stop somewhere. There are a ton of cute little features, but to cover them all would take forever. The point is simple: this is one impressive feat of engineering, but it also a sterling example of musical engineering. As to sound quality, the K2000 sounds a bit conservative alongside the super-bright digital sounds of other synths. The sounds are accurate rather than punchy (although the processing capabilities are such that if you want more of a synthetic character, you can get it). One warning: the non-linear functions can sound pretty nasty on their own. They become usable when teamed with appropriate filter settings and tunings, but this takes some experimentation.

The K2000 is not without precedent. Ensoniq pioneered the use of onboard effects, the Xpander turned modulation into an art form, the sampled transients recall Roland's LA synthesis, combining samples with other synthesis engines brings to mind Yamaha's latest offerings, and the emphasis on expansion takes a page right out of Peavey's book. The non-linear shapers are direct descendents from Electronotes (a pioneering newsletter for musical engineers). This is why the K2000 is so exciting: it provides very fertile ground for those who want to go beyond the preset mentality.

Overall, the K2000 is a triumph. The sound quality is excellent, the user interface is unparalleled, the engineering is state-of-the-art. What's most important, though, is that the K2000 meets the future head-on yet incorporates the best of the past, right down to filters that close all the way down to 0, like the old Buchla machines. In a world of me-too synthesizers with virtually interchangeable samples, the K2000 stands out as an example of creative musical engineering. It's not cheap — especially when you add up the cost of expansion modules, an external hard disk, and sample RAM — but it sets the standard by which other synthesizers will be judged in 1992.

Craig Anderton is the author of 11 books and has played on, produced, or mixed 10 albums. He has done sound design work for Emu, Ensoniq, Oberheim, Peavey, and Yamaha; his circuit designs have been used by artists like Boston, Van Halen, Sammy Hagar, and the Motels.

Further information

£ tbo

The UK distributorship of Kurzweil products is currently changing hands; at the time of going to press we were unable to confirm who will represent the company in the UK.


Stereo Chorus
Stereo Flange
Stereo Delay
4-Tap Delay
Ultimate Reverb
Room Simulator
Gated Reverb
Reverse Reverb
3-Band Pseudo-Parametric EQ
9-Band Graphic EQ
3-Band Pseudo-Parametric
3-Band Pseudo-Parametric
Lowpass EQ+Gated Reverb+Mixer
Lowpass EQ+Reverse Reverb+Mixer
3-Band Pseudo-Parametric
3-Band Pseudo-Parametric
EQ+Chorus+4-Tap Delay+Mixer
EQ+Flange+4-Tap Delay+Mixer


1-19: Multi-sampled traditional instruments (piano, electric piano, voices, guitar, strings, bass, flute, brass, etc.).
20-38: Drum kits, including a General MIDI compatible kit.
39-68: Individual drums and cymbals.
69-72: Percussion kits.
73-83: Individual percussion (ind. four conga variations).
84-87: Long, evolving exotic percussion loops (sci-fi soundtrack fodder).
88-108: Attack transients.
109-111: Short multi-samples (marimba, solo strings, muted guitar)
112-167: Single cycle waveforms (lots of drawbar, partial, and synth waveforms).
168: Silence.


8MB of onboard samples, expandable later this year to 24MB with optional expansion board 4 SIMM sockets for optional sample RAM (expandable to 64MB with 16MB SIMMs)

Optional internal hard disk

Stereo sampling option with analogue and digital I/O (2nd quarter 1992)

16-part multi-timbral, 24-note polyphonic On-board effects

2 stereo outs, 2 aux stereo pairs (also used os inserts for patching external processors, or 4 mono outputs; not affected by master volume control), headphone jack

61-note keyboard with velocity, release velocity, pressure; transmits on up to three MIDI channels simultaneously

Receives poly pressure data

3.5" MS-DOS compatible floppy drive

SCSI port for hard disk/CD-ROM/future fast sample transfers via SMDI

200 ROM Programs

Pitch wheel, mod wheel, slider, pedal, dual footswitch controllers

Program RAM can be allocated to some combination of up to 200 user Programs or up to 15,000 note sequences

Ploys MIDI Type 0 sequences loaded from disk; records songs as well as multi-timbral sequences received over MIDI

240 X 64 pixel backlit LCD


Algorithm DSP functions fall into the following categories (remember that you can modulate the parameters). Not all functions are available for all algorithms, but with 31 algorithms to choose from, there are a lot of variations.

Filters: 17 different types, including low-pass, high-pass, band-pass, all-pass, and notch, with several choices of the number of poles.

Equalisation: single stage parametric, pseudo-parametric with fixed width, one-pole bass boost/cut, one-pole treble boost/cut, and two-pole bass boost/cut.

Pitch/Amplitude/Pan Position: pitch, overall amplitude, panner, stereo overall amplitude/balance for algorithms that split the signal prior to the output.

Mixers: combine split signals back into mono.

Waveforms: sine, sawtooth, and square; audio and low-frequency versions, the latter of which can serve as additional LFOs. These waves are generated by oscillators and are not sampled, so they can be bent huge amounts or have portamento applied. With split algorithms, they can furnish additional waveforms, or add ring modulation effects when the final amp stage is a balanced modulator; otherwise they 'mask' any sample that is present.

Added Waveforms: sine, sawtooth, and noise waveforms can be added at various points in the algorithm to supplement the existing sample.

Non-Linear Functions: these 'glorified fuzztone' functions generate harmonics. High frequency stimulator is an exciter-type device; distortion, clipping low pass filter, and pulse-width modulation do what you'd expect. The three flavours of 'shaper' modules are very interesting, giving effects that resemble resonant filtering and vocal-like formants (having the module track velocity is particularly interesting). The only way I can think to describe the Wrap function is as 'punk hard sync'.

Waveforms with Non-Linear Inputs: this is a kind of 'punk Yamaha RCM' in that it combines samples with other waveforms, but does so in a non-linear fashion. I won't even try to describe these on paper!

Mixers with Non-Linear Inputs: there are four functions, two of which provide ring modulation effects; the '! Amp' function sums two splits together and runs the result through a shaper, then a module that multiplies two input signals then multiplies the result again.

Hard Sync: yes, that classic sound can be yours in all its digital glory (ie., the oscillators don't drift and mess up the tuning).

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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 - Mar 1992

Gear in this article:

Synthesizer > Kurzweil > K2000

Gear Tags:

Digital Synth

Review by Craig Anderton

Previous article in this issue:

> Too Good To Be True?

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