I highly suspect that any solution is going to cost more than just buying another used Scarlett

 

You can do a lot with Network bridging and audio these days. Perhaps the solution is not solely reliant on just the audio interface.
The fact it is a used Scarlett does not help either.

 

OP, please give some context. Why do you want to record to two pc's at the same time? Why not record on one and then copy to the other if it's really necessary to be on two computers. I can only imagine it's for editing purposes, because you're going to get exactly the same recording on both if you can pull this off, then just copy it. Why spend money on hardware (and you will) to pull this off. I can't imagine why. If you record to two pc's, then which one do you monitor on the headphones? Please, I'm trying to understand why you would need this.

 

I just woke up so forgive me if my answer sounds ridiculous, but why not just get an audio interface, such as a sound mixer with more than one output?

 

He would still need an interface on each computer to use each use the signal from the dual (line)output interface to the usb on the computer. There is no interface, afaik, that has dual usb output.

 

Your prior post hit upon my main point. All of those details could have been supplied. Instead, we are here typing all this stuff out; like some guy who thinks we should do his research and shopping for him. It's all terribly lazy. But then people who want hand-crafted detailed explanations for the things they do not know, or even the right questions to ask; will be the first ones to complain when someone who actually knows the answer does not want their time wasted with spoonfeeding and will use an AI for their light work.


Built-in dual host connectivity means an audio interface can connect to two computers at the same time without needing to switch cables or restart the device. Some interfaces offer this feature using dual USB, USB + Thunderbolt, or networking (AVB/Dante).

Interfaces with True Dual Host Connectivity

1. RME Fireface UFX+ – Supports both USB 3.0 and Thunderbolt 2, allowing two computers to be connected simultaneously.
2. Antelope Orion Studio Synergy Core – Has USB and Thunderbolt connections, but simultaneous use depends on software configuration.
3. MOTU AVB Interfaces (like 624, 8A, 16A, or 828es via AVB) – If both computers support AVB Ethernet, they can communicate over a network.
4. Presonus Quantum 4848 – Thunderbolt-based, but limited simultaneous dual-computer usage.
5. Apogee Symphony I/O Mk II – Some configurations allow for USB and Thunderbolt host switching.

 

Connected yes, used simultaneously NO!

Only networking solutions like Dante or AVB will work, no USB/TB hosts simultaneously.

 

Me too, until it broke a couple of years ago out of warranty. I was happy with the way it worked but I replaced it with a MOTU M4 because I had lost faith in iConnectaudio4+ reliability.

 

Here's a guy on Reddit 3yrs ago who connected a Windows machine and a Mac machine to the same 18i20.
I actually am pretty sure that you can do one connection with USB or TB and another with a USB to Optical connection if the interface has both (mine does).
The main OP used a USB power switch. Other people on this thread describe their experiences some doing it differently if anyone wants to read it.
https://www.reddit.com/r/Focusrite/comments/rpkgh0/connected_focusrite_18i20_to_two_computers/

 

Again, switching, not two computers simultaneously. The OP wants to record on two machines simultaneously, so needs both connected at the same time.

 

actually not HUB but KVM switch might work - but most cheap ones are designed just to share/toggle mouse+keyboard with 2-8 computers connected
it would be kinda trial and error, not sure if worth the time and money spent

 

Look at my post towards the top with pictures. I run a Virtual machine through a bridged network on VMWARE and if I play two different audio files at the same time, one on the HW and the other in the VM, they play simultaneously. It sounds fricking horrible but it works.
So if it can be done virtually, then it can definitely be done with physical hardware.

 

DANTE

 

Many audio interfaces come with them that are decent shown below. Many mainboard manufacturers have ditched optical for USB-C and they were mainly optical out those that had them.

 

I had that 18i20 and it was the worst interface I have ever owned, as far as software goes. It was just after they switched the MK2 or MK3 and they went from MixControl software to Focusrite Control. It was terrible, on Mac anyway. For a couple hundred bucks more the 828es absolutely smokes it. The 18i20 held it's value very well though. I used it for well over a year, and when I sold it I got back about 100$ less than I bought it for. If I had known that, it would have been gone much sooner. I was ready to catapult it out the window.

It would drop connection to the machine over and over and over. Their software would be like, "no device found". Reboot, and it would do the same thing. At one point, I was calling it the Focusrite Rain Dance trying to get it to work. Various connection variation attempts boot sequence.

 

I love it - each to their own. It records beautifully for me and it's quiet. Did you have Gen1 or Gen2? Mine's Gen3. I believe the earlier Gen hardware versions were rife with problems. I'm on PC with it so maybe they have issues on Mac as you insinuated?
You know if you have Gen3 because it comes with USB-C.

 

Last edited: Feb 28, 2025

I did not have a Windows machine at that time to test it with, so I can't say. I fully expected to get some nasty email from the guy who bought it from me on reverb, and he never mentioned a thing about it. I just looked and it was probably 2nd Gen from the date.

There is no personal preference involved though. This is the AVB http-based external hardware dsp mixer. Everything about it is on another level.





touch console mixing panel




routing is very easy once you set it up right:

 

Last edited: Feb 28, 2025

Yes that would drive me nuts. sorry you had such a horrible experience. I must be lucky or got the generation hardware that did not have those issues.

 

You'd know if it was 3rd Gen - see the USB2 white plug next to the world clock? It's a USB-C on Generation 3.

 

If that is the only visual difference, I can't say for certain. I think it was the one pictured. Was there an MK3, Gen-2? I remember that mark number more from having to pick the third available software download link, which was Focusrite Control. I became an expert at downloading and installing it, as you can imagine.

Focusrite Control was new software to them, and their tech support did not even really know it all that well yet. And on Mac only also. That's why I metion that, because the guy I sold it to was on Windows. I would not have been surprised in any way if it had come right back in a box. Like I said though, he never even mentioned it.