You can build sounds with arrangers too. The PSR740 has 761 voices and five DSPs with 38 basic effects and up to 102 presets on each DSP with up to 16 parameters per effect, including LFO, filters, EQ etc. It also has multi-timbrality which allows you to assign any part to any channel so you can layer up to 18 voices though you would normally allow eight of these for the rhythm. Each part also has its own set of effects. The only snag is that you need a computer to access all of this so I use I cheap laptop and XGworks. When you move up to the PSR2000 and higher you get more of the same and you can access a lot of this stuff at the console though you need the computer to get full access. With the computer you can save all your settings as a .syx file and the limit on the number of settings is the size of your HDD. So an arranger is also a workstation, particularly if it has a sequencer. All you need is your imagination and the ability to decipher the documentation.

Bryan