The first Ketron product to use "AUDIO" was actually the MS-series in the late '80 (which used GROOVES/Sliced Audio) on some of the style and most that were offered later on disk.

The X-series was the frist to implement actual Audio and grant user access to the Audio parts - which they could now use to program their own styles or within user styles... This followed through into the XD and SD series.

The AUDYA took it to a whole new level with maintaining the Grooves plus now streaming complete AUDIO Drums (plus AUDIO on Guitars and Bass) plus gave the user access to use, mix and match whiile being able to sync all this to the current tempo....etc!!

I understood the post/topic to be "what keyboard made the biggest upgrade" - so if you were to say look at the Tyros line from Yamaha, the PA line from Korg, the G-series from Roland, the AUDYA-series from Ketron ... or which manufacturer made the biggest leap forward ... etc (maybe I miss-understood)? I believe Ketron and Korg have offered the most upgrades per product line (additional content/features within subsequent OS releases to an existing product, not number of upgrades).

Thanks,