Key action is excellent, velocity seems to waver between soft, medium, and extremely hard, and aftertouch is ever-present. I've never had the problem others seem to have with the noise, but I tend to play it at lower volumes. The real problems arise when you try to use it as anything but a glorified piano. I've owned mine for two years and I've still not gotten it to sound like anything I want.

Unless you have some real waveform knowledge and the patience to sit down with the manual and climb the learning curve, you'll never use it as anything but a well-built (but crummy sounding) preset synth or a very, very good controller keyboard.

However, I would recommend taking this review with a grain of salt. I am obviously not the target market for the K5, I prefer knobs to displays and I love my Korg Polysix. If you are interested in some complex synth technology that has a great deal of potential, the K5 may well be the synth for you. If you are interested in a live instrument or a simple beginner's synth, the K5 is most certainly not for you.

2 for Extreme Niche.

It was a good controller keyboard with its flexible midi routing, layering and splitting options.

The sounds were fairly distinctive though the filter lacked the ability to sweep frequncies. No onboard effects either which was a shame.

There was a graphic editor available. I have that software.

I also have the K5m. This rackmountable version of the K5 has the same features.

My K5 outputs are very badly distorted and I have been unable to find anyone who can fix it. It would probably be cheaper to buy some software based additive synths.

The sounds are sadly dated now though the piano remains outstanding.

I doubt if you will get much out of these keyboards for much longer.

Unless you can repair these things yourself they are not worth buying.

but...what i wanted to get at was that the filter on this sounds really quite good. i am kind of in shock that there is absolutely no zipper noise on adjustments of it...pretty nice.

somewhat puzzled by the flat lv parameter....the k5 is full of these strangely named parameters.

how would you like an lfo which could be trendy (a fade in before before the delay if on)?

or how about effecting an envelope (a sine lfo which can be adjusted in speed and effects an envelopes output depth level).

how about those living harmonics!...pooh on the dead ones....hehe.

i've had my k5 for about 2 weeks now, and i'm just now starting to dig around in the synthesis engine. its really quite a strangely configured instrument...but its turning out to be really quite flexible and engaging to program from the unit itself (contrary to what others have said).

i've never really been very comfortable with rate/level envelopes...but for some reason they are just clicking with me on the k5 here. sweet! they can be a little bit unpredictable to adjust though....the relationship between the rate and how it reacts with the level is a little puzzling. as your tweaking the level the time it takes for the segment to arrive changes....i guess i still have some homework to do on that matter...but...the k5 is quick to navigate and tweaks are made in real time, yes! i have found a lot of other synthesizers and samplers of this era are not. so you can't just hit a note and tweak 'till you find your sweet spot...you must keep on retriggering the note as your tweaking....bleh...i really haven't liked that at all.

suprise suprise for the k5.

some of the multi layered piano patches sound very good, some very realstic sounding imatative patches in the kawai collection, not really what i'm interested in...but its impressive to me that someone did the work they did to pull these off. this isn't casual tweaking here. i'm sure they did a lot of analysis of the sounds which they reinterpreted into k5 patches. i'm curious to find one of these programs for the mac that will try to do this for you, that is...analyze a sound and spit out a k5 patch. i'm sure i can do this manually, its just a matter of grasping the practices and concepts involved....mister fourier comes to mind, and that pvoc utility in csound.

i did find a mac k5 editor (email me at sophalicus at charter dot net if you can't find it)...but for right now i'm just using it to load and dump patches, the k5 is bit easier to jump in and tweak at this point.

the aliasing, clicking and digital crunchiness is kind of cute. ;)

some noise in the outputs...oh well, there is that output mod...which i probobly won't do as a little noise doesn't bother me to much. owning a sidstation has set my noise level bitchyness threshold quite high!

my unit has the mandatory basically dead backlight, i just have a clip on lamp placed above it which works fine, someone elses idea...thanks whomver that was.

keys, velocity on/off and aftertouch are great! this is why i bought the keyboard. i needed a nice controller to replace my broken esq1.

the pedal inputs seem to be broken on mine...cause when i plug one in it only works in like half the useable range (as being midi echoed out the unit) and once i get to like 60 i start to get this weird and not very pleasant humming which only gets louder and louder...i the pedal works fine with my other equipment. so i can only guess something is amiss with the k5.

sometimes my unit sends out a lone spurious expression pedal message which makes the soundengine click. a few of the keys have either weird velocity response or they sometimes don't trigger, hasn't bother me too much.

overall i am quite happy with this $150 purchase! i got 3 ram cards and a manual to boot!