Unbalanced instrument/keyboard to aurora balanced

Ok. Check the specs on the outputs of your keyboards. They probably output a signal that's about 20db or so below typical line level (which is what the aurora is expecting) and they possibly have a high impedance (keyboards vary widely in this regard). Most people reccomend that the receiving device (Aurora) have an input impedance 10 times higher than the source's output impedance (your keyboards and modules) for optimal loading..   

However, the Aurora "accepts" unbalanced signals just fine. (Input impedance 12khz for unbalanced). So you' should be getting signal into the Aurora, but it might not be at the levels you'd like to see. (Did you try the "-10" sensitivity setting on the input trims of the Aurora?)

So even without a DI, and mic pre you'll get something, but maybe not a robust signal, and possibly slightly anemic sounding with the potential impedance loading scenario...

Here's another article in Sound on Sound that would be a good read. I know you don't WANT to have to have a DI and a preamp, but there's a lot of things we don't necessarily WANT to have to do to get great sounds...

https://www.soundonsound.com/sound-advice/q-there-any-point-di-ing-keyboards

Hope this helps!

Edited by chops - September/04/2017 at 9:24am

It's not so much a question of balanced/unbalanced, but a question of impedance and signal level. Your keyboards are likely outputting a high impedance, instrument level, unbalanced signal. The lynx is looking for line level. You ideally want to feed the outputs of your your keyboards into some di's and mic pres, or a mixer, and then take the line livel balanced outputs of those into the inputs of the lynx. (Not that it won't work at all the way you're talking about... just not ideal.)

(I'm a Lynx user, not a Lynx representative of any kind. Just thought I could help...)