I'm not familiar with zeta..... BUT, in TTS, in the set up box where you select the patch and bank and inputs and outputs, there is also a "key" field. It's normally set to "0" . But it can be adjusted up or down..... -12 for example would make the notes play one octave lower. +2 would play the next whole step up.
I see you solved the issue.... but this is something you may find useful in the future..... a few synths I've seen have some way to change the key.