The XT series utilizes the wavetable synthesis pioneered by the PPG Wave back in the late 70's and early 80's. Essentially, an XT is a modern, working verion of the PPG Wave 2, albeit with a much higher available bandwidth (which can, by the way, be reduced to sound like a PPG if you so desire.)

The XT is unusual, as are all wavetable synths, and is capable of creating odd, evolving and moody textures as well as hard, stabbing pulses, bleeps, etc... The XT is great for new age, industrial or trance music. However, those seeking out analog emulation had best look elsewhere, in my opinion--as the XT is NOT a virtual analog, and falls short of recreating classic instruments like the Junos, Odysseys, Jupiters, Moogs, etc... Those desiring "true" analog sounds should look to another unit such as a Virus, Nord or Prophecy which are more true to the analog sound. (Especially the Nord, if you ask me.)

On the positive side, the XT is unique and offers great programmability, although the envelope settings can take a minute or two to get adjusted to. With onboard ring mod, FM/x-mod, and noise crazy sounds are always just around the corner. Sound quality is good, if a little bright, but the XT definately can cut through a mix when necessary. The arpeggiator is decently implemented, if somewhat buried too deep in the menus to be spontaneously useful. Pretty versatile too. The XT's construction is solid, and not nearly as ugly as I originally believed it would be. The XTK itself is about the right size and width of a synth--although it weighs much more than you would expect at first glance.

On the downside, the XT's filter is perhaps a little too whistly, and much of its self-oscillation algorithm is (to me) non-musical. The inability to dedicate different wavetables to each oscillator is a major disappointment--oh, the wasted possibilities! Too many annoying menus and sub-menus! When will manufacturers start creating both dedicated voice controls as well as program controls? A number of important functions are buried under menus that are not immediately obvious. For one reason or another, the LFO's on the XT seem noticeably weaker and less interesting than the Nord/Supernova/Virus crowd. As usual, the preset sounds are terrible. Typically, Waldorf feel that they must have stock presets of Moogs, "Arps", Wurlies, Clavinets and Junos in order to sell their product. What a waste, to make an unusual instrument such as this try (and badly at that) to sound like a Mini or 2600.

In all, the XT is unique and sounds good overall. However, all of the typical limitations of digital synthesis are present--weak LFO's and not-so great filter. The (typical) lack of good interfacing for control parameters can be frustrating at times, as is the way too small LED screen, which should be at least twice as large. I judge the XT as worth it for the sheer uniqueness of the unit.

I wasn't sure if the 2-line LCD display was adequate, but combined with the convenient menu subgroup buttons, data wheel and of course the famous set of knobs, it turned out to be all right.

I just started programming the thing, and it's not too easy, but in general if you know analog synth prgramming you'll be able to get some results right off the bat. Mastering the wavetables can take a while, I suppose.

The CC control is very nice.

The sound of this machine is huge. Two sweepable wavetable LFO's with a lot of available cross modulations, combined with a really nice filter, produce an incredible result. The filter is very smooth and self-oscillates nicely. In fact, it can be used as the third oscillator, because it can track the keyboard so precisely. The result is just stunning.

LFO's are syncable to the MIDI clock, and have settings like 1/8T etc. Which means you can have extremely interesting syncopated filter-swept arpeggios.

The arpeggiator is handy, and effects not bad, although many presets are over-effected, which is common. I wish it had more FX processing power, a little more polyphony and and extra set of outputs, but as it is it's well worth the money. I chose it over other synths and I'm very glad I did.