A synthesizer is a very specific instrument.
A synthesiser must have one or more oscillators operating in the audible range of frequencies to generate the raw sound. Things which are not synthesisers: sample-playback machines, filters, low-frequency oscillators, chorus / reverb / delay effects, distortion boxes, compressors, vocoders etc.
All of that sound could be made without resorting to synths. To be fair though, it seems like quite a lot of work to make synth like sounds, without using synths; if their claim is true, it means they've sampled some things, cut out some utterly tiny loops to basically create simple almost sine-wave like notes, and then run all of that shit through a bunch of the other boxes listed above.
So, they've basically simulated synths, using all the components you'd get in a synth, except replacing the first oscillation-generation step with a sample-playback step; so they're only not using synths on a technicality.
(, Wed 19 Nov 2014, 14:51, Reply)