You can get a genuine SSD from Ketron and this is the option I strongly suggest. They are more expensive than standard consumer grade drives though. Initially they used a Transcend Industrial SSD which has now been discontinued. They now use Cervoz Momentus Series.

You need to remember the drives on your Audya are being used quite heavily because the audio data streams in real time. If its for home use you dont have to be too concerned, but if you plan to use your keyboard live then you should probably buy the correct drive via Ketron and ignore the next paragraph.

You can use a cheaper consumer grade SSD but make sure you have backups of everything. I have tried Kingston, Transcend and Kingspec - none of the ones I tried work properly and either the DISK LED is stuck on RED constantly or the drive is not detected at all, even adding the cable jumper does not work. Zenho drives work but you need to modify the cable otherwise the Audya does not register the drive.

The Transcend drive Ketron supplied until recently is a 64gb TS64GPSD330. If its not this number (or possibly the TS128GPSD330) it will likely not work - i know from experience. You should be able to use the 128gb version, but the keyboard will format the drive to 80gb. If you are able to find the correct model number (unlikely) you will need to modify the Audya IDE cable. Once you have done so you will not be able to use your original hard drive unless you have a spare cable (these are not easy to find either)

The new Cervoz Momentus drive is not available to the public as far as i am aware. The cable does not need to be modified for this drive and is a drop in replacement.

Official drives are preloaded with the factory data.

When changing Hard or SSD drives, any USB updates purchased and installed on the original drive will no longer operate and you will need to contact Ketron for assistance.