The Roland D70 is a budget synthesiser (around £500) which, although low on price, is very high on features. Featuring LA synthesis, it comes with a large number of sampled sounds which are consequently possible to alter by altering not only the level of effects applied but also the ADSR and the levels of the patches which make up each 'instrument'.
In this way, it is possible to rapidly alter the very professional sounds beyond all recoginition. It is very easy to combine a horn line made punchy by its shortened AD cycle with some extremely slow release flute. On top of this add an insane pulse based bass note and suddenly you've got a bass sound to be reckoned with. Having done this, there is no good reason why you shouldn't alter the levels of each of the three parts in this sound (perhaps in realtime while the D70 is being driven from an external sequencer) to add variety and spice to your music. Perhaps bring in a fourth part to this sound and change the feel entirely.
Save any five of these patches in the internal memory together in a performance and use them all at once or individually. Together with the drum part common to each performace (although easy to alter for individuality) this is 21 part multi timbrality and 30 part polyphony.
The D70 is also very useful as a master keyboard in a midi setup, capable of controlling up to five other midi devices in a very easy to use manner. in fact, the hardest part of the setup is working out where the midi leads go! Currently Psychiatric Beat Therapy (a member of the MDBC) use a D70 to drive an SR16 drum machine, a TR606, a Novation BassStation and an Akai sampler. This setup works very well and I've personally seen it in action to great effect in their more recent work.
This keyboard is about as far as five hundred quid goes, especially if you buy it with about ten ram cards. These are not really necessary, but do hold a lot of new sounds to play with. It is prety good, although it can be quite difficult to get extremely fat bass sounds a la Korg Prophecy, although with a good EQ and FX box almost anything is possible. The onboard effects are very crisp, and you can almost do away with using an external FX box on this one.