First of all, sorry to hear that the reboot didn’t work out! I had chimed in with a bit of invest to get MOD Audio booted, and are still upholding this offer if there is any request for that from @gianfranco and @friedsilence.
As also suggested @Dave1138 above I suggest to look at Monome for a possible way that might work for you as well.
The software is all open and there is a huge community over on the Lines forum.
The main hardware pieces are Grid and Norns (there are more, but some are discontinued or very specialized or modules for a Modular Synth). Norns is Linux-based audio computer with audio, midi, and network interfaces in a nice package and could be a good a model that might work for a continuation of MOD as well.
The devices are rather high valued ($900 USD) and only produced in small batches. This is currently also not without issues as outlined by the team.
Additional, there is (or rather was, now discontinued) a low-cost solution based on a custom Raspberry Pi shield, maybe a bit similar to the PiSound. It is functionality almost equivalent to the big Norns device, but far away from the finish and usability in a live rig. The software is the same for both. There are also additional 3rd party variants of that (e.g. Fates), mostly based on a RPi as well.
Monome is a small-scale operations, basically 2-4 people working on hardware and software with the community chiming in for the main software.
I’m not sure if the Monome core team can make a living just from the hardware sales or if this is just a side operation, so using this model depends a lot on the requirements and expectations of the MOD Audio team. But there are surely some lessons to be learned from that.
Based on the previous comments in this thread and others I would suggest to not go the full business model, at least not in the sense of taking the whole thing private and close down on the SW as well.
The code is out anyway and the community will keep that alive for the current MOD owners and maybe even strengthen and update the 3rd party Pi-based variants (PiSound, …) to overcome the lack of devices.
Instead I would suggest to concentrate on a software-only/mainly approach and embrace 3rd party solutions. The trick of course is to monetize this approach, not to trick people in making you rich (which strangely people tend to assume…), but to get (at least) enough out of it to make a decent living and keep the whole thing together and alive and provide enough drive and dedicated effort to not just maintain the MOD portal, but also to continue development.
The key to this would be the (or a) portal, download site and forum, as they act as the key to the community. As long as most people follow this and stick together with a future MOD company we can keep this all afloat.
Offering subscriptions or options for one-time payments (without threatening to “brick” the device when stopping to pay) might turn out just enough for an initially small operation. Let’s grow it from there!
Getting back into the HW business would be a way for more profitability. Similar to Monome, the really nice Norns devices are maybe only bought by a small group of people, but that’s a high-margin niche (again the caveats of current HW productions apply). And for the rest of the crowd there’s still the more affordable (I wouldn’t call it cheap) way based on RPi and other, existing devices.
Here the high flexibility of the underlying Linux ecosystem is really an advantage, as this basically runs on anything. Even offering something for widely used consoles (Steam, …) might be an option, as long as there is a way to get audio in and out.
Providing accessible and ready-to-use commercial packages could make it easy to get it up and running, but for a price. This is what would appeal to most musicians which are not also nerds/tinkerers.
Leaving the door open for the community will allow tinkering with shared effort which will help the community as a whole, while not jeopardizing sales too much as a) tinkerers and people with the right skills anyway know how to build their own thing or get around any restrictions and b) might actually (understand the) value (of) such an ecosystem!
Having said all that, the first priority should be your own and your families health and satisfaction and being able to make a living.
I will now go an buy a Dwarf from Thomann, as long as any are available… (so if my Tier 3 device ever shows up, I have one to share or use two :-))
I’m still up for a contribution/invest into getting a company booted up, so hopping for some path forward here.
All the best, whatever path you choose!