I use the RJM mini mixer. https://www.rjmmusic.com/minilinemixer.php

I built my own spliter tthat takes the dry amp signal and splits it to 3 seperate signals that feed the Timefactor, Space and dry back to the mini mixer. I'm going out of an Egnater M4 without a loop, so I need to have the dry signal sent to the mixer but you won't need to do that part.

Here's my board:

The mini mixer is the box on the left and the custom built splitter is the next small box over.

You could simply use a Y-cable in your application to split the signal off the parallel loop.

There are a number of other products you can use to split the signal and mix the Eventide pedals. You could get very sofisticated with it as well using something like a switchblade that would allow you to programatically change the position of the pedals or go from serial to parallel routing.

Here are some other products you could potentially use (You won't need a splitter for these):

Xotic Stereo X-Blender:  http://www.xotic.us/customshop/item_sxb1.html

Pigtronix Keymaster: https://www.pigtronix.com/products/keymaster/

Suhr MiniMix II: http://www.themadape.com/Suhr_MiniMix_II_Line_Mixer_p/s-minimix.htm

And if you want the most flexable/programable option and have money to spare there is the Switchblade 8F: http://www.soundsculpture.com/products/switchblade8f.htm

Let me know if you have any questions.