Kurzweil K2500S

v5.01 with KDFX all roms int hd, This machine has been very easy to use, cos i have owned just about every synth on the market also used 2 have a k2000rs which was the
only synth 2 replace my roland W30. once u get ur head around it, its very fast 2 use

Love this machine, in the uk not alot of users but thats a good thing, I do all types of music & totally blown everyone away with this machines sounds, softsynths dont come anywhere close to this. owned since 1996 expanded since day 1, cant find a replacement for this yet, owned the new korgs, rolands, yamahas etc, still comming with killer sounds now!!! The sequencer has been excellent, sampling, and ram tracks b4 any1 has even thought of it.

Any1 would think this machine had just come out. live in for processing through the killer VAST engine then onto KDFX, dsp generators when originally let out on the k2000 in 1992 way ahead of its time. if in the right hand very dangerous peace of kit. can be as nice (pianos and that stuff) or as nasty as you
want, lovely!!!!!!!!!!!!!!!! Bring on the competition been waiting a while now.................

No probs bar a few worn buttons due 2 heavy use which i replaced myself( not 4 beginers, me electronic eng ok)

Always been good, more free uprates would be nice though

Cant be beaten, only a new k3500s would be nice. Boughts this in 1996 whe n the trinity came out, k2500s still kicking ass, but where are the trinity's now... Would buy again whatever, sell my family if I had 2..

OS 4.76. It came with a lower OS, which (when upgraded) opened up entirely new classes of effects and effect chains in the KDFX card, excellent work Kurzweil!! I can't wait to see what they give us next, the unit has the potential to expand like crazy, let's hope they take full advantage of that!

The presets range from passable to ridiculous. Fortunately, with a little study of the enormous manuals, you'll discover how easy it is to edit patches and create your own sounds. The interface is almost self-explanitory, and you can learn new tricks for getting around by consulting the manuals. It's easy to experiment with new sounds and techniques, and inject real imagination into every patch. Fun!

The manuals are 99% comprehensive and easy to understand. The KDFX Algorythm Reference book comes with >schematic diagrams< of each special effect, for crying out loud.

48-voice polyphony, however the basic programs (Kurzweil's name for 'patches', essentially) can contain between 1 and 3 voices, which uses up the poly more quickly. I've run out of polyphony a few times, and I've had to devise work-arounds. There are also "drum programs" which can contain up to 32 voices per. The keyboard is quite, in fact you can adjust the keyboard's response curve in many different ways (this is something you'll get used to with the K2x00 series -- you can adjust EVERYTHING!!)

By itself, the unit comes with a Digitech effects chip, which if it's anything like the one I used on my school's K2000 years ago, is a total waste of time. However, you can pay extra for the KDFX card, which has all kinds of wonderful effects (realistic reverbs, chorii, flangers, tube amp simulators, wavetable shapers, delays, etc etc and new ones that came with OS 4.76 that don't even have proper documentation yet.) KDFX is very powerful, unfortunately I frequently run out of PAUs, which are the processors that power the KDFX algorythms. Some algs require more PAUs than others, and you only get 4 PAUs to allocate for standard effects, and 3 PAUs for a single auxiliary effect that comes after the standard effects. If I had more gear then I doubt this would be a problem, unfortunately I'm using the K2500S as the mainstay of my studio.

Also, regarding KDFX: Every single parameter of every effects algorythm can be adjusted in real-time. Yep, it sounds amazing :) This used to be easy to set up, however the new OS has made it a pain to implement real-time effect adjustments. It's far too easy to disengage the real-time control just by flipping between the 16 channels, and I hope that they fix this in the next version of the OS.

Adjusting the programs in real-time, though, is a breeze, and the machine has 2 ribbon controllers (one is pressure sensitive), a mod wheel, pitch wheel, room for 4 footswitches (I haven't needed more than one!) and _8_ vertical sliders/faders to do the job. Fun fun fun.

Mine came with 4 megs of sample memory, upgradable up to 128 megs, but I haven't done that yet... I look forward to getting more, though, this is yet another realm where it's easy to run out of room.

I haven't played with the sequencer (I'm triggering everything using Vision 4.5.1) but everyone swears it's amazing, and I don't doubt it.

Okay, this is what I've been waiting to write about. The K2500S has "V.A.S.T." synthesis technology, which offers a _lot_ of control over the sound programs. For every layer in a program, you get to choose an algorythm (31 different networks of DSP functions, and usually _many_ different DSP functions selectable within each block), and then you can modulate their parameters using 2 LFO's, 2 ASR's, 2 velocity triggers, and 4 functions chosen from an immense array of mathematical and chaotic operators. If you're not intent on having your programs sound "realistic", then this will be your playground -- there's a LOT to explore here. I've had this synth for just over half a year, and I'm still discovering its capabilities every time I create new programs.

KDFX sounds wonderful, for the most part -- it's time-consuming to adjust so many parameters, I actually would have liked to have more 'unrealistic' presets, especially in regards to the reverbs. Guess I'll have to fish them out myself.

Okay, I do a few gripes that will bump my rating down from a 10 to a 9:

* There's no FM synthesis. You get a wide world of AM and ring modulation capabilities, but there's no FM anywhere. (Yet...? Maybe they'll get the rights from Yamaha and surprise us come next OS release! Fingers crossed...)

* The built-in waveforms are uninspiring, as are most of the extra samples I've downloaded from their FTP site. The drums, in particular, fill me with dread and hatred -- These are the most sterile, expressionless drums I've ever heard. Great for studio jazz, terrible if you want to project your heart and soul into your music. Fortunately, you can load your own samples into RAM (I'm lucky enough to have 7 gigs worth sitting on my hard drive) but this is time-consuming, and they're erased when you turn the machine off, so you have to load them in anew every time you power up.

* Kurzweil has lowered the prices of K2600's below what I paid for my K2500. The K2600 has a broader ability to chain DSP functions together, and also allows the user to install their own devices (sound expansion packs and sample RAM, etc) on their own, without taking the machine to a dealer to be serviced. Grr. If only I'd waited a few months... anger.

So far, so good! I treat it like a baby, though, it's never gonna leave the house. People say the K2600 is sturdier, though, so again.... grr.

Haven't dealt with them yet.

If it was stolen, I'd go with a K2600. Otherwise, I'm enjoying it, and it's been a blessing! I don't have a lot in the way of gear, but with the K2500S at my side, I won't need anything else for a long time.

OS v4.04 (w/KDFX) I find the K2 series quite easy to use, tough I have had the benifit of starting with the K2000 v1.0 in 1992, upgrading/updating hardware and software about twice a year. The interface is easy to get around, and editing of programs and samples can be done quite efectively without any need for external software. The presets are "OK", and are good starting points for creating your own custom patches. There is a lot of creative programming in the presets, and the VAST architecture seems nearly unlimited in depth for creation of new sounds. The best feature of the K2 series is the combination of sampler and synthesizer, the inherent flexibility of these together allows for extreme manipulation of samples, and the ability of the K2500 to resample it's own output allows this to operate much like a 24 track stereo (48 mono) digital multitrack.

48 voices, with a robust voice stealing algorythm. Sounds great even with all voices being used, no apparent latency or drop in quality when maxing out the polyphony. The KDFX option adds tremendous depth to the K2500, plenty of real time modulation sources, and editability on par with the synthesizers (VAST) capabilities. The built in "DigiTech" FX chip was a major drawback to the K2000/K2500, though it can be used in a K25000 with KDFX, I usually set it to 0% wet/dry to disable it. I have expanded my K2500 with all avialable options, including 128MB Sample RAM, 1.25Mb of battery backed (3xAA) P-RAM for storage of Programs, Effects, Sequences and Setup information. Also there are 3 ROM expansions, a 4Mb Stereo Piano (built into the ROM expansion daughterboard), an 8Mb Orchestral ROM, and an 8Mb Contemporory ROM. Each ROM expansion adds a group of "presets" to the program listing (1000 total) the built in sounds are 0-199, Piano 770-799, Contemporary 800-899, and Orchestral 900-999. Also added are Multitimbral "Setups" which allow for up to 8 layers of Programs for easy live control. There is room for an internal SCSI hard drive (mounting kit required). A great feature of the K2500 is the ability for the operating system to be uploaded from Floppy/SCSI, new OS versions are available from Kurzweil's FTP site. Some of the recent updates have added a "KB3 Mode" for organ /drawbar simulation which can exceed the limit of 48 voices (I believe up to 96 voices or more), and a "Live Mode" which allows for the real time processing of external signals through the VAST and KDFX architectures without having to sample the signal first (quite useful for "Mastering" a mix). The KDFX expansion is a multiple bus for effects, and can have up to 4+1 busses of simultenous FX, though usually less because there is a limit of PAU (processor allocation units) available, and most algorythms use more than 1 unit. The K2 series MIDI implementation is about as standard as is gets, much unlike many of the contemporary synthesizers on the market, it uses standard terminology whenever possible. There is a consistancy with the MIDI channel/track equavalence, and the manuals list the many MIDI control sources in detail, as well as mappings for percussion and continuous controllers. It is NOT "General MIDI", though can be configured as such with software on the FTP site. The K2500 also offers a bank of 8 MIDI sliders/faders which can be mapped to any MIDI control source, for control of the K2500 or any external MIDI gear (controlling on-screen faders in StudioVision or knobs in ReBirth for example). Other real time control surfaces such as pressure sensitive ribbons,and panel switches, as well as 4 MIDI pedal inputs, and 2 external CC inputs offer a lot of flexibility for triggering notes and modulation sources.

Many of the preset programs are based upon emulation of real instruments, and could be used out of the box for any number of musical styles. There are also a lot of Analog synthesizer programs which are very versitile. I highly recommend learning and using the editing capabilities of the K2 since there are so many posibilities for creating unique, expressive sounds. On-board effects "suck", though they do offer excellent real time control possibilities, the noise level is high, and the limit of a single global effect is a problem (solution=KDFX). The K2500 has a lightly weighted 76 key action, somewhere between unweighted synth keys, and a heavy spring piano key. The K2500X has a heavier action as well as a full 88 keys. The velocity and pressure sensitivity can be set to a number or preset renges, as well as custom curves. The intonation can also be adjusted to emulate non-equal tempermant tunings.

The K2500 is large and heavy,the K2500X even bigger. Recommend using a ATA approved flight case, or at least a padded case for any travel outside of the studio. Never, never, never ship via UPS. If you do need to ship, be sure to insure it for the full amount. As for user installable options, someone familliar with installing PC components, soldering, and static sensitive precautions should be able to do almost any of the modifications him/herself, though you will void the warranty. The KDFX should only be installed by a qualified technitian.

Personal experiences, quite good, though if repairs are needed, Kurzweil has proven to be pretty slow for returning the equipment. Very friendly, and informative, email via the K2000 user list is the best way to answer any questions.

If it were stollen, I would hunt down and emasculate the theif. Definately would be replaced with the same. I have been using K2/K2500 for almost 8 years, and cannot justify the purchase of any other hardware. I absolutely love some of the hidden features, and only wish that there were even more frequent software updates.

seems to be easy to use. there's so much available that it confuses me on a regular basis. i have all the ROM add-ons and they are nice. the piano add-on blows the internal piano away... nice presence... put on some headphones and close your eyes and you can hear the positioning of the strings... nice effect.

48 polyphony... great action effects are there... nothing to get excited over. kdfx is avalable now lots of things you can put in this sucker. i have all 3 roms 32 megs of RAM an internal 850 scsi hard drive too many features which is good and bad since i dont know where to start

the add-on ROMS are spectacular the internal sounds are good also.

its been more dependable than my ensoniq asr-10 i'd play live without a backup if i had to

buy again? possibly been playing for 20 years somds great, can get sounds from pc disks... I GET LOST IN IT needs better effects but kdfx is out and it should be good it helps me attempt to make music... if i wasn't so lazy i thought it was neat that sound forge on my computer could talk to it and grab sounds from it or send sounds to it via SCSI

Presets are OK on the K2500. When you turn it on initially, you have 200 patches (what Kurzweil calls programs) available for use. However, do NOT think this is Bad, or that the initial "Ok" rating is an indication of patch quality. The problem (as I see it) for the Kurzweil folks is that there is SO MUCH you can do with the patch editor that trimming the on-board sounds to a reasonable number was a major problem. To emphasis this, the keyboard comes with a "farm" disk containing almost 2000 more patches in every style imaginable.
And it also comes with 100 "setups", what are combis or perfs on other boards. Since the K2500 can have up to 32 layers per sound (on the 1st 8 tracks plus one more) and 8 zones on the keyboard, setups are pretty damned powerful.
I've never made a setup, but the patch editing is good to overwhelming. There is a huge amount you can do. And it's easy to tweak to standard sounds to get jsut what you want.
The manuals (two of 'em) are excellent. No other word for it, just the best keyboard manuals I've had, and I've had ensoniq, Korg, Yamaha and Moog manuals

Poly is 48 note. But I do have to say that with 192 occilators and a "smart" voice stealing algorhytm it's hard to overload it. Hard, but not impossible. As an example, I've blown the polyphony with 4 rhythm tracks then 4 piano tracks, at one point all the pianos are chording left hand and right and that blew it out. HOWEVER, the sequencer (more later) has some handy features that allowed me to work around this pretty easily.
Effects are OK, nothing stunning, your typical reverbs, flanges,and so on. Note that the patch editor is so sophisticated that you may not need effects for many sounds, you can build it into the patch. Which is good, because the stupid thing still has only ONE effect at a time. The KDFX upgrade is supposed to fix this, but it's more than a year overdue.
Now for the sequencer..... This is the best keyboard based sequencer I have used or know of, bar none. I'm not going to mention all the features, since many of them are the ones you know should be there on any good sequencer, I'll just hit the highlights; 32 tracks of data, to begin with. That means (effetively) that you can be driving 16 channels on the K2500 and 16 channels on an outboard piece of gear at once (yes, you can drive all 32 on the K2500, but for various reasons this isn't a great idea).
Songs: the K2500 has the ability to chain sequences together to make one long arrangement, and then add 16 more tracks on top of that arrangement. I had this feature on my KS-32 and loved it, then ensoniq dropped it from their later boards. Roland almost has this on the XP-80, but it's harder to use. This feature makes the K2500 a complete creation/arragment/mixdown machine.
Editing: The K2500 sequencer has the BEST sequence editing tools out there. Event editing is GREAT, easy to find the MIDI event you want to tweak. Track commands, everything from simple time-shifting (and easy way to fix polyphony overload problems) to reference quantitizing is right there and easy to use.
Sense of place: You always know where you are. Sounds simple, but it means a TON! Whenever you are anyplace (almost) in the sequencing environment you ALWAYS can see what track you're on, what beat you're at, and what is going on. No guessing.
Very easy to use: What to go back a few bars? Put the cursor over the "location" parameter on the playback screen and spin the wheel counterclockwise, you back up a few bars and replay that section. Sounds trivial, but that's WITHOUT having to hit stop/play again, that's WITHOUT having the track parameters reset themselves, that's WITHOUT having to hit anything!
I'll admit, I love this sequencer.
Another thing to mention, and part of the reason why the sequencer can be this good, is the display size. The LCD display allows 8-10 lines of 80 character text. What that means is in the event editor, for example, you can see 8 events at a time! So you can change a group of note durations WITHOUT getting lost or forgetting. And on and on. I've never seen better.

All the sounds sound very good, very clear, very realistic.
I use this for dance/ambient/dub, and I play classical for my own enjoyment, and the range of on-board and available sounds is great for all these types of music.
Effects are boring, very run of the mill. Doesn't even have a rotary speaker simulator yet. The effects upgrade is "soon", but it's been "soon" for over a year.
This is a very responsive keyboard. The keys are just weighted, there's no "hammer drop" action, but it still feels very very nice. I can swing and be inspired by playing these keys.
ppp to fff control is easy. My opinion, aftertouch is a little too stiff.

I have had enough freezes to be annoyed.
But every time I've frozen has been either in the sampler or the sequencer, not while actually playing live or playing a sequence, so it's robust. I still would carry a backup harddrive on a gig.

Kurzweil has great on-line support. At their web site, on AOL and CompuServe, and directly through EMail I have always gotten good responses, and their tech support guy is always posting his phone number for people to call to work ouut problems.
Also, you can upgrade the operating system from floppy disks, and Kurzweil has been upgrading the K2500 OS about once every 6 months.

I would buy it again. I love the sequencer. I love the sound editor. I don't like the lame and limited effects, and hope desperatly that the effects upgrade will fix my problems.
I comparo'd it against the XP-80, the Korg N-XX series, and even bought an ensoniq MR-76 (and took it back the next day because of the lame sequencer) before buying. Sound quality and sequencer sold me.
It inspires me. The sounds and the sequencer are so easy to use that I can quickly take a piece from improvisational entry to a 80% done song. Switching sounds, getting sounds from the net, or playing the setups is constantly inspiring me to create new music. For example, I wrote a Jazz piece a few weeks ago, and I hate Jazz! But one setup and some sounds just push my creative bumb into it.
I will say, however, that US$4000 is a big chunk of change, and had I not gotten a nice size royalty check right before buying this board I might have settled for less power.