Recently I picked up a used Ketron SD40 from an individual while waiting for the new SD90 arranger module.

I really like Ketron sounds (vArranger sounds excellent on my Ketron S4 module) and the OS but the variation "A" button wasn't working. I thought it was a bug but when I tried a SysEx message, it worked. So it is a hardware issue in my case as AJ mentioned, and AJ is going to send me a new switch.

I've read a lot of past posts in regards to Ketron here and on the Ketron forum. Musicians who own both Ketron products and other TOTL such as the Genos and other keyboards seem to prefer their Ketron arranger. Lack of support from Ketron Italy has been a concern for me, but I guess that's where AJ comes in. I read lots of posts recommending his excellent support. AJ whose background is in Information Technology must be indeed very knowledgeable for him to come up with his own upgrade kits for Ketron products. So all these factors gave me confidence to go in full force with Ketron when it comes to my hardware needs. I will probably get the Ajamsonic upgrade kit and his Super Gold Styles.