Kurzweil K2500RS

Like all great things, it takes time to adjust to the designers methods and thinking. Its worth the effort. 6 Months and your on your way

The features I think are more than adequate. As a composer and songwriter I have never had to use midi as I prefer live multitracking, but the sequencer is a great tool for referencing certain concepts and ideas.

I have so many keyboards including the new yamaha motif XS8 and every other piece of gear I can get my hands on. 8 synths and a number of pianos. The piano and string sounds on this 2500 are better than anything in the market short of Miraslov vitos or some thing like that.
As far as hardware sounds, the kurzweil surpasses the new yamaha XS8 or the new roland Phantom or anything else. Kurzweil has produced the rolls Royce of keyboards. I own several of the same kurzweil models just for backup. everything else is disposable.KDFX is a must.

Using everyday for over 10 years. No problem although when I first put all the rom cards in it i did find a screw driver that the manufacturer left in it. HA Ha. Only thing ever changed is new keyboard assembly. No big deal.

Its all in who you know. Kurzweil is coming back and their support is getting better. Remember the Guitar center who I do not buy from. Well in the day when they were getting to big, they stopped carrying kurzweil. Thats what hurt kurzweil for sometime. But not now. Kurzweil is still making the best and the guitar center is nothing more than a diminishing toy store.

I have 3 oof the same model and also the k2500 keyboards. Its simply the best even in the year 2008

Finally decided to put up reviews for all my gear, so I'll start here since this is the centerpiece of my home studio. First off, the 2 manuals are roughly the size of the phonebook, so that should give some idea of how complicated a unit it is. I'm using OS 3.02 which is the newest for units without the KDFX option. There's a pretty steep learning curve just because of the sheer volume of parameters and menues, but once you get the hang of it it's very easy to work with. They weren't kidding when they aptly named the system V.A.S.T.

The unit really shines here. Mine's fully loaded except for the KDFX. 128 megs of Ram, P-Ram, Sampling, daughter board w/ all ROMs. If you do a lot of sequencing with it (which is what I mainly use it for) be sure you get the P-Ram. With a 100 meg zip attached it's almost impossible to run out of storage, and if you do just store to your pc. In this day the 450 sounds it come with seems low compared to new stuff that ships with like over 1000 sounds, but how many of those sounds will you actually use anyway? Besides, this was made back in '95 and it can still compete with the newest Tritons and Fantoms, which should say a LOT.

I bought the unit not only for the exhausting list of features, but also the actual sound of the unit. I make industrial/experimental music, and this thing just has that 'dark' sound. Play one alongside a Yamaha Motif and you'll see what I mean. The piano sounds are the best I've heard on ANY synth, and it can make some seriously dark pads as well. V.A.S.T. is really all about creating your own sounds though, and you can make just about anything you can possibly imagine with this synth, which further sets it apart from other workstations which seem limited in actual sound creation. I mainly use this as a hardware sequencer/sampler, as I have plenty of other synths to create sounds with, but this one just has a great tone that can't be ignored.

Built like a cinder-block. You could probably hospitalize someone if you threw it at them. I've never had a problem.

Excellent! I've only emailed them a couple times with a question and got an email back within a day. Can't ask much more than that.

If it broke I would be pissed, and probably buy another one. I've been using it as my main sequencer for about four years now, and it is just like a second nature for me to use now. I'd hate to have to go to software for my sequencing needs because I use all hardware synths and it would be extremely counter-productive to have to move to the next room to my pc evertime i want to sequence something. Some will be intimidated by the learning curve, but once you realize the potential of its astronomical number of functions you will be very pleased, plus at the price you can get them for on ebay these days it's a steal.

Version 3.02. Many presets are excellent, some are flat. The important point is that the presets were designed to show how powerful vast can be in completely altering the nature of the original sampled sound. VAST is not trivial to use, but with some reading of the manual, it's not too difficult either. You just need to put some time into it. Manual is good. The sequencer is very easy to use and quite good.

48 voices is plenty with the thick sound per voice possible and the excellent voice-stealing technology Kurzweil developed. Good effects, decent expansion possibilities. Good sequencer.

Some of the better samples I've heard compared with other brands. VAST can make things sound truly amazing -- the effects help here too. Velocity and aftertouch-sensitivity sensing, pitch bend, modulation, etc.

No problems with mine, but I've come across more than one 2500R/RS with problems. Fine for the studio from my experience.

With operational support, you always have to leave a message. They do return your call and have been helpful. But good luck getting technical support quickly if you're desperate.

These Kurzweil synths are dirt cheap used and you get an incredible amount of power. I would certainly replace mine ASAP if it were stolen. The only thing I miss is the ability to burn finished audio CDs like the Korg Triton Studio. It also doesn't have an arpeggiator (unless I've missed it?) Otherwise, it has pretty much everything I want.

Currently using OS version 5.01, that further improves ease of use. The Kurweil is told to be difficult to use, but it is not after you learn the basic principles.
Presets are a mix of nice and so-so. I preferred K2000 v.2 over all other sets, but it is easy to customized the basic set of presets taking from the huge amount of great quality sounds available in the supplied factory disks, or around the web.
Editing can be done at great depth. This is the most powerful and versatile synth ever. A patch editor like Emagic's SoundDiver can be handy.
User's manuals are useful, well organiwzd and complete, but they lack some decent tutorials for beginners.

Polyphony is very limited (48 notes), but it can be enough, considering that even a single voice can sound wonderful. Adding a second K2x00 is easy, thanks to some useful coupling functions.
The basic FX processor is outdated and noisy. Installing the KDFX gives you one of the best FX processors on the market. KDFX has the same steep learning curve of the remaining parts of the instruments but then you discover it is logically set.
You can expand this instrument with a piano ROM (basically, the nice Micropiano) and the two Orchestral and Contemporary boards. Memory can be expanded up to 128MB using 72-pin SIMMs. The sampling option is optional, and of very good quality. It also gives you digital interfacing.
MIDI implementation is complete and extensive. You can also choose your Porgram Change system. Controllers are completely assignable.
The sequencer is not spectacular, but it is good for scratch idea taking. It also records audio, that may be useful to record from a mic, or to sample the K's output.
I love the integrated SCSI interface, to add CD-ROM readers and hard disks. There is a very powerful disk management in this unit. The DOS/ISO9660-compliant format is very handy.

The basic acoustic sounds are nice, very usable. They can produce impressive results, especially when mixed and processed through the KDFX. This instrument always cuts through the mix, and this testifies of its sound quality. I don't know of other synths faring so well in this department. Others may be more impressive when used alone, but they are usually less easy to mix.
The sound is deep and mellow. It can reach very low frequencies, and never sounds harsh. Very sweet sounding indeed, or very powerful when you need it powerful. Basses are great for dance and techno.Motion synths sound sweety digital, and are great for elektronica. Thanks to LiveMode and extensive realtime control, it can also be used as a realtime DSP for experimental music.
The Orchestral board makes it very good for orchestra simulation (go listen to the demos). I could finish scoring projects with little help from additional libraries on CD. Organs made with the KB3 sound fantastic to me.
Touch responsiveness is what made me choose a Kurzweil at first. This instrument is very musical.

It is solidly built, and very reliable. No problems in >three years of use, as I did not have with my previous K2000R. Anyway, there is some old technology inside, that may not be totally reliable.

The Italian distributor is very good at assisting. Personnel from the American laboratories are always very supportive at answering to emails. Service Centers are very rare.

I will certainly buy a new Kurzweil, if there is a new synth with the same advanced features. I will probably buy a K2600 to expand polyphony.
This instrument is about all I need to make music. I've other synths, but they get used very often.

I know - everybody hates it. Personally i sold my 2500rs and tried to do all that stuff in software synths/samplers. That was a big mistake... I tried all known software and, to be perfectly honest, i'll buy 2500 again because of its synt/sampler capabilities. Hardware mahine gives you reliability. I find 2500rs really easy to use. You have to read that manual and fully understand it! It's not so hard just take your time and RTFM... Presets? I don't think any serious guy would use presets. Anyway... You can do really weird things with this machine, even spontaneously... Get used to editing 2000/2500 from it's front panel and you won't need any software editor. Manual is not the best but readable.

48 polyphony is enough. More than enough if you understand what you are doing. Who needs 48 voice pad?? If you do multitrack hard disk recording 48 should satisfy your needs.
Effect processor is really noisy. Never used it. KDFX? I don't believe it. 128 ram is ok. Rom expansion is usless unless you're a preset guy. Midi capabilities are quite extensive. Internal sequencer is good for showing internal demos not more. Though if you have really strong nerves you can try it. I really hate Kurzweil because they don't upgrade it's hardware, more powerfull means more complex synthesis algorithms etc. I hate Kurzweil cuz they're not going to support 24/96 etc.... Last note 2500 has sophisticated synthesis/sampling capabilities and i'd rather concentrate on exploring this part then analyze it's hardware features. Hardware features - 2, software features 9.

It can be expressive if you program it properly. Good for weird music ^)
Sounds good in mid range.

Reliable in studio. Wouldn't use it on gig. More reliable than software sampler.
A friend of mine had a really big proble with one - ad/da board was blown out due to power failure. Get an UPS and protect your unit.

they answered my email.

It's not worth that kind of money due to its limited hardware capabilities but I'm going to buy 2500 again.

Presets are not the best thing about the machine. Some (20%) I have used in production. However there are literally thousands of free patches out there on the Internet.
You need to program and be a good synth programmer to be able to enjoy this machine. If you are, the sky is the limit.
Remember that this is probably the most complex synth/sampler in the market so my compliments to Kurzweil for making the interface so easy to use. The big screen also helps.
The manuals are great, well written and even funny at times. And huge.
So, although this is an INCREDIBLY complex machine, it could be also impossible to program (like the FS1R for example) but this is definitely not the case - so I'll give it an 8.

The optional KDFX effects processor is amazing - high end studio quality. (answering the guy above - to route one fx to each output, use preset #198). The Digitech effects that the machine ships with are really basic and uninteresting but acceptable for keyboard-quality gear.
The real feature about this machine is the comination kick-ass sampler with a programmer's-dream synth engine. So, anything that you sample will sound good and can be used to feed the synth as a waveform.

It is very programmable and will respond to anything. If you learn how to program it.

Don't gig with it if you can. I gig with it and I do have a backup. It is a delicate thing, suited best for the studio.
I totally depend on it.

The community is very supportive, Kurzweil themselves very helpful. But the best is that they are CONSTANTLY upgrading the OS and including more features.

I own two of these and am going to buy another one (or maybe a K2600). It is the heart of my studio and the heart of the band I play with. I have never ever ever found anything that is so deep and flexible. If you program synthesizers start saving - you NEED one of these. If you don't program synths or want something with knobs for each parameter, this is not for you.

It is possible to work some magic straight out of the box, especially if you popped for the piano, contemporary, and orchestral ROMs. The presets are very good and quite useable without further tweaking. However, the real magic of this monster exists a bit deeper, and you'll have to conquer a bit of a learning curve before you can really start to use it. It's no wonder that the manuals are as large as they are. However, once you get used to it, it gets more and more intuitive every time you use it. Kurzweil packed a lot of power into this box, and the fact that this power is accessable at all (without the user having to jump through a million hoops) is remarkable.

This is a real beast when fully loaded. From Kurzweil's web site: "48-note polyphony; easy upgradability; 60 internal digital sound processing functions; up to 28 MB of internal ROM sounds; sample RAM expansion to 128 MB; dual SCSI ports; a myriad of interfacing options; and economical program memory expansion to 1.256 MB."

There is also a special mode available called "KB3 Mode." This is a mode that emulates the Hammond B3 organ, with full control over just about every parameter you can imagine. If you have a slider box like the Peavey PC 1600x, you can control this mode via sliders the same way that the original B3 used drawbars. The fun doesn't stop there - if you dig into the KB3 programs, you can change the sound sources and apply KB3 processing to anything. It's pretty astounding, but there's a tradeoff: KB3 programs devour machine resources to the point where you can't do much else if you have a KB3 program loaded. It's best used as either a live playback mode or as a mixdown-time replacement for a temporary placeholder sound.

The K2500RS model comes with a sampling option standard. It can be further upgraded to include a multichannel digital interface (DMTi and KDS), as well as an extremely powerful effects module called KDFX. KDFX requires a bit of setup to be fully appreciated, so allow me to explain.

The base RS unit has 5 pairs of outputs, only four of which can really be used at any time. There are four "dry" pairs (labeled A, B, C, and D) and one "main" pair which has effects applied to it. If you use the main out pair, you can't plug into the A pair. The effects in the base unit use a Digitech chip that has a reputation for being a tiny bit noisy (I've never had an issue with this, personally). Also, only one set of effects can be applied to the main out at a time. The effects in the program selected for the primary MIDI channel (channel 1 by default, but selectable) determine the effects for the entire main out pair mix, overriding any effects called for in programs on other MIDI channels.

However, if you get the KDFX unit, the Digitech chip is bypassed and a quieter effects processor kicks in. The best part about KDFX is that you get full access to effects on pairs A, B, C, and D. The KDFX processor is *much* more powerful than the Digitech chip, and people are finally starting to take advantage of this in some programs found on the web.

Another feature that the K2500RS offers is "live mode." This turns the sampling inputs into an I/O channel. You can pass sounds into the machine, perform full V.A.S.T. programming on them (see below), and route them back out with realtime control. I/O jacks are a common feature nowadays on many synths, samplers, and sound modules, but few of the modules that offer it can do as much with the sound as the K2500RS can.

As mentioned earlier, there is a feature called V.A.S.T. ("Variable Architecture Synthesis Technology"). This is where the 60 available functions kicks in. You can mangle any ROM or RAM sample to your heart's content with this feature. I won't even attempt to describe it - hell, even some of the experts on V.A.S.T. programming don't grasp 100% of its power. Suffice it to say that if you want to do something to a sound, you can almost certainly do it with this feature.

Finally, the K2500RS can be upgraded by software. These downloads are posted for free on Kurzweil's FTP site. They often add new and exciting features to the machine in addition to any needed fixes. In fact, live mode and KB3 mode were software upgrades. Kurzweil doesn't release upgrades very often, but when they do, they're usually *well* worth the download.

If you get the fully loaded K2500RS unit (all 3 ROM cards), you get some pretty useable stuff. The orchestral ROM is quite good, although the strings are an acquired taste. Many of the ROM sounds are adjustable in realtime via MIDI controller messages. These are fully documented if you want to start tweaking from scratch. I've personally published a ready-to-use controller setup for Peavey PC 1600x users (go to http://gameaudio.3dportal.com and dig around in my miscellaneous files section to find it).

There are about as many programs available on the web for Kurzweil synths as Carter has Little Liver Pills, to use an old expression. Put simply, there are too many to count. These range from basic twists on existing ROM programs to full-blown V.A.S.T.-augmented programs that include RAM samples. One set of programs even lets you turn your K2500RS into a more techno-sounding K2VX. You will never run into a shortage of factory or user made programs.

If there is one shortcoming to the K2500RS, it's that it doesn't have self-oscillating resonant filters. The filters it has are very good and can pull off a good deal of resonance, but they'll never fool you into thinking that you're listening to a Waldorf synth. You can get pretty close to some popular sounds, though. Pink Floyd used a Kurzweil synth, and some of their sounds come with the unit.

The sample playback capabilities of the K2500RS are terrific, especially if you have the full 128MB of sample RAM. You've got full V.A.S.T. power over your samples, and the sound quality is pristine. Sample CDs can be a problem - most people program for just Akai, and sometimes maybe E-Mu. Kurzweil-native collections aren't extremely common, but they do exist for the major libraries (Miroslav Vitous orchestral, Spectrasonics Symphony of Voices, etc.). It reads Akai format CDs, but occasionally something gets lost in the translation. If you want to make your own samples, though, you're in luck: it's SCSI/SMDI-compatible, and it can be connected to and fed by a Mac or PC. You can grab samples from any source, even the K2500RS itself, transfer them to an editing program such as Sound Forge, mess around with them, and then transfer them back as quickly as you downloaded them.

As mentioned earlier, the effects on the base unit are good but not stellar. KDFX effects are reported to be incredibly good. Alas, I only have the base Digiffects chip, but it has served me well.

The K2500RS responds to velocity, aftertouch, expression, volume, pitch wheel, and modulation just as you'd expect most synths to respond. Most of the ROM programs are set up this way, but if you want to change things, there's nothing stopping you. Everything is mappable and re-mappable. The keyboard version (K2500S) has 8 sliders, two wheels (pitch and modulation), and two ribbon controllers. Believe it or not, these are accessable in the rackmount K2500RS unit - just send the appropriate controller number and data (fully documented), and you're in business.

I have yet to find a genre of music that the K2500RS wouldn't work with, mainly due to the fact that it's a sampler as well as a synth. There are better sound sources for analog dance/techno styles, but the K2500RS does a passable job and can fit well into a mix. I've personally used in for classical, rock, rap, techno, and other styles.

My unit doesn't move. It's in a studio, and it's staying there. That said, I've never *needed* to move it. It's been rock-solid since day one.

Kurzweil has outstanding online tech support. They have an official representative who is very active in the Kurzweil users mailing list. The mailing list is an invaluable resource. If you've got a question about how to do something, you can bet that someone on the list will be able to tell you how to do it.

I've never had to call them for support, so I can't judge that aspect.

The K2500RS is the backbone of my studio. Without it, I can't make music. Plain and simple. I wouldn't trade it for anything in the world...well, maybe for an upgrade to the K2600RS.... :-) It's not cheap by any definition, but I've certainly got a heap of value out of it.

before software version 4.03 and now software version 4.21 with KDFX
the presets are a little more than audibles and very hard edit them.
I tried some editor and no-one worked fine.
The manual is no more than readable.

The 48 voice poliphony is very insufficent in a sound module of this
price and name.
The stock effect module is quite sufficent for a channel and extremely
difficult to program.
The expansion capabilitys are big but expensive and the quality of
the sounds and of the effect module is not at the level of the prices
to pay to get them. The configurations of the memory for the samples
are extremely limimited by the hardware af the sound module and do not
permit to reuse the memory you have from previuos PCs.

I found the natural sounds very far from the realistic ones and very
difficult to manipulate.
The KDFX is not the best example of the digital tecnology and very,
very different from what is mentioned in the advertisings of the same
Kurzweil. try to get an fx for every channel if you are able.
Not to mention the leslie effect for the (fantomatic) KB3.

No!!! absolutely you cannnot depend on it for your important jobs
expecially when you have to accomodate the interests of thirdy parts.
I purchased it in february 1999 and only in october i used it working
well.

about the customer support i have to communicate you what happened to
me in order to avoid you the same problem:
in 9.29.1999 i sent to the italian reseller of the Kurzweil products
Casale Bauer of Bologna a K2500r for a check-up and i tought the
opportunity of equip the instrument with some parts i needed.
In fact by 9.27.1999 i had sent to my fiduciary store (Magazzino
Merula of Roreto) an e-mail for an estimate for a KDFX, the entire
series of roms, a DMTI and an ADAT interface for the DMTI.
It was the far, very far 9.27.1999 and just at that time at Casale
Bauer were (so they told to Franco of Magazzino Merula) awaiting for
the restocking from the home for this important and indispensable
component.
In the meantime the K2500r is at home and i am alwais awaiting for
the DMAL-8 ADAT interface for a DMTI that i cannot use in my setup
without it.
I put aside, at this moment, some unpleasant facts sufficient reasons by
themselves to evaluate a selling organization! I only make you know
that i have phoned many times for information, and was half november
when somebody told me that i have to wait still for tho weeks (2) too
cause the delay of the same Kurzweil in this delivery.
I send an e-mail to the kurzweil support to bring to their knowledge
that Casale Bauer usually remains for such time without Kurzweil
fittings but also to make them know the fact that Casale Bauer puts
the blame of this on the delay of their support so everyone can
easily understand reading those few lines of text derived from
an e-mail sent by Mr. Zocco of Casale Bauer to me dated 11.5.1999:
"Le posso ovviamente dire che l'Interfaccia ADAT per DMTI e
regolarmente in distribuzione e con questo intendo che quando non
ne disponiamo vuol dire che ne siamo in attesa dalla casa madre.
La ordini pure presso i Magazzini Merula e saranno gli operatori del
Rivenditore a tenerla informata.
Cordiali Saluti.
> Salvatore B. Zocco
> (Product Manager
> M. Casale Bauer S.p.A.)
> tel. +39 051 766.648
> fax +39 051 766.525
> e-mail szocco@casalebauer.com
"
I am sure that you can translate those simple words and understand the
meanings!!
Well the most wonderful thing of this is the replay of Young-Chang
America to my e-mail of information dated 11/25/99 from the customer
support:
"I will be out for the next week or so because of the birth of my son.
I will respond to all messages in the order received as soon as I
return.Thanks for your patience.
Sincerely,"
and this is the reply at the return from the weekly vacation and
received after 12/4/99:
"I work for Young Chang America and have nothing to do with
distribution or service outside of the US. Please contact:
Young Chang Europe
Industriering 45
D-41751 Viersen
Germany
49-2162-4491 (phone)
49-2162041744 (fax)
info@kurzweil-europe.de
www.kurzweil-europe.de
--
David Fox
Kurzweil Sales Info"
so as if the kurzweil support relies on one (1) employee' and the
american branch is not the same as the european branch!? WONDERFUL!!
For these raisons the kurzweil customer support is absolutely to
avoid accurately. THE BEST IS TO AVOID THE WHOLE KURZWEIL PRODUCTION!
the DMAL-8 is in my home from 12/18/99. 2 months and half to get it!!

I do not love robbers in my home and i prefer do not consider this.
I only tell you that i will spend no more else 1 penny for a k2500
because of its reliability (it was broken), its sounds, its roms and
its support.
i have some other sound modules and are all working fine.

There are 100 presets. I can find a use for 80 of them, but this is definitely not a box you will buy and never program.
The screen is nice and big, and there are plenty of programming controls on the front panel, so for once you won't need a separate patch editor to do serious patch editing. The most beautiful feature of the programming section of the operating system is that all values are expressed in natural units. That is, instead of setting your sine wave LFO to "55" out of "128", you can set it to 10Hz -- and it will actually display "10Hz" on the screen. It's amazing more synths don't do this -- it's so obvious.
There are two manuals, both huge. The unit also often ships with one or two instructional video tapes. This is all great, only it all reads like a reference manual when most of it should read like a tutorial. The synthesis architecture is extremely complicated, robust, and powerful. Coupled with the fact that you will be using your own samples, in addition to the factory ROM samples, learning how to *really* program a K2500 takes a month or so.
There are several free K2000 programming tutorials available on the internet. 99% of this material applies to the K2500 as well.

The K2500 can play back 48 samples at a time. Divide that up as you will into stereo samples and layers of samples up to 32 deep per channel. You also have at your disposal over a hundred digital oscillators, capable of, for example, adding a saw wave during sample playback. This is ample polyphony for a synthesist, although it may disappoint you if you expect to simulate a full orchestra.
There are built-in effects. Nobody likes them very much. At the time I'm writing this, Kurzweil is planning an expansion module to remedy this "problem." I find the build-in effects useful, although perhaps not exciting.
The unit can be expanded and upgraded in many ways, both at the software (operating system) level and at the hardware level. Since the operating system can be user-upgraded, the operating system is regularly upgraded, giving the synth new features (an appregiator was added in one revision, for example.)
The most common hardware expansion is sample RAM, which allows you to use your own sample data rather than being limited to the ROM samples. This is a cornerstone of the flexibility and power of the K2500.
A more full description of options and expansions can be found at the Kurzweil web site.
The K2500RS's MIDI implementation is thorough. It allows you to choose from three different bank/program select methods, for example. It does omit useless MIDI features such as active sensing.
There is an on-board sequencer that has fantastic resolution and is fairly easy to master if you've delt with non-graphic MIDI sequencers before. I use it all the time to keep my fingers away from the computer keyboard, and on the MIDI controller.
The real "feature" of the K2500 (and the K2000, for that matter) is that it gives you all of the features you'd want in a really awesome sample playback synth, and on top of that, lets you record/monkey with the samples themselves. No other "synth" or "sampler" quite does it as well as a K2500.

The best sound quality of the K2500 is achieved with 48K/sx16bit sample playback, mixing each of the audio outs individually in a mixer having a -120dB noise floor, circumventing the internal effects entirely. There are few other synths or samplers that can match this sound quality -- certainly nothing else at the K2500's price point.
K2500's are used for everything from simulating the world's greatest piano to making minimalist-industrial-techno-hi-nrg-dark-wave-blipcore play-back-/vmlinux-into-/dev/audio-straight-up-noise. The sampling option is obviously to blame for this.
Since I'm reviewing the K2500RS (rackmount) I won't say anything about the keyboard version, except that it has been well received by all I've talked to.

Here's the bad part; she's an unforgiving monster.
All will work well if you follow the manual's instructions. Exactly.
I have heard many horror stories of broken K2500s resulting from the curious putting cables where they don't belong, or attempting factory mods at home.
Buy from an authorized Kurzweil dealer who'll give you a good warranty, who will install all the options you may get in the future for you, and she's perfectly roadworthy ... Just please do support the ass end of the unit in your rack if you're going to move the rack around a lot.

Customer support is great. Especially Kurzweil's internet presence.

This is the very heart and soul of my synth rig, and will be for some time to come.