Questions about modifiyng a Unicab build


Hi, I want to build an ampless rig around a Unicab PCB. I have found a bunch of nice posts about this same topic, but cannot get all the info I am looking for, but I am sure more people have attempted this same thing...

I want to make the Unicab as similar to original as posible with a headphone out, maybe an XLR out (more on this later) and I would like to add some sort of preamp on front of it so it actually works as a full amp sim (closer to the Simplifier, than to the actual CabSim). So let me toggle each question separately:

About the headphone output, I have seen a bunch of headphone amps with very similar designs (by Pedalpcb, but also by TH Customs, Moonn Electronics, and others). My doubt is in case I want to add this circuit in parallel to the main output, would I need to add some sort of buffered splitter or merger of any type? Or I can just go ahead and get a second cable from the Unicab output and solder it into the Headphone circuit input?

About the XLR output, the Unicab has a line out that I could connect directly to my interface or mixer console on my rehearsal room. In order to use it in live venues0, do you consider that I would need the extra DI out? Every single place I play, they always have DI boxes where they always plug anything that is even line level (like synths and keyboards). But I don't know if I would be better of by adding an extra DI out output like the one on the original CabSim. In that case, I have seen a couple circuits I could try out but once again, would I need to do anything special with the Unicab out? Or I can just add a third cable to the Uni's out so now one goes to the main out, another one to the lineout/XLR out, the third one to the Headphone out.

Last but not least... About the input preamp, I was thinking on adding something like a Son of Ben, or a Cobbler, or one of the Catalinbread style foundation drives. This is as straight forward as it seems, right? Just send whatever preamp/OD circuit I end up going with outs into the Unicab input. This would "limit" my setup into having one single "amp" style, but I do feel like that is what I really want to go for. Will probably go with the Cobbler as I love Ac type of chimmey cleans and I can always just add a plexi type of drive in front of it in case I want something different. Was maybe planning on doing some sort of loop so I can add different designs, but I find this would make the whole project a bit more cumbersome and kinda beats the point of going with a very basic one amp(less) rig I can use as my Vox ac15 without having to carry an amp around.

Thanks in advance! Really looking forward to starting this whole project
If you’re interested in a shortcut, check out the Destiny Behemoth project @jjjimi84 did. I think it’s pretty similar to what you’re trying to accomplish. Dan was selling boards a while back (I still haven’t finished mine) he might still have some.

Even if you’re set on doing your own thing I bet he’d have some solid advice for you.
This is exactly what I was looking for, haha. Dont need some of the extra stuff like the reverb and I would enjoy trying a few different preamp/colouring options, but the project itself is just the same idea I have. Thank you so much!