Can GLK5 work with midi guitar3 hex alone?

I can’t use gm800 as my sound card,i have multiple input and output

Sure you can use a GM-800 as a MG3Hex interface, I do this all the time.

I have two guitar inputs and two pairs of stereo outputs, so I can’t use the GM800 as my sound card.

The Hex PU signals come in via USB. You just need to connect some speakers to the outputs of the GM-800 and make the selections in the MG3 setup accordingly.

Can I use the Antelope Zeng Quadro as a sound card and then use the GLK5 to connect the MG3HEX?

I don’t think that this works.

Your input must come from the GM-800 and if you are on Mac you could select any other soundcard as output.

What do you mean by “GLK5”?