Very interesting discussion -- and a big thanks to Chris to stepping into the ring on this!
I will say, I really think you need to decide what you want to do yourself and what you think the best market is. Along the lines of the Homer-designed car, everyone will have different ideas on what is absolutely essential. I remember a few years back either here or on the Oade board, an engineer at Zaxcom came on looking for input on what they could make for a stripped down recorder (stripped down from Zaxcom's perspective
) and how they could reach our market. They got info pulling them in 10 directions at once, and not surprisingly never came up with that small, 2channel recorder they were discussing.
Maybe you should think about making a couple different preamps to meet different market segments, using the knowledge you gain from your R&D. I'd imagine that the work you do on working out the internal voltage rails and 48v powering could easily apply to a couple different preamps -- one that is small for the stealth market, and one that is bigger to meet everyone's needs.
If you just want to make one and decide to go with a larger design, you'll be having a lot more competition. V2/V3, UA5, Oade modded all-in-one recorders like the ACM671 and HDP2, etc, etc. Some of those options have other functionality you wouldn't be offering, like an A/D section or full recording capabilities, so your preamp will come up short for those people not wanting multiple boxes.
From my standpoint, it seems like there is a open niche for a really nice sounding, very small preamp that people could use with a R09 or MT to do 24-bit stealth recordings. But that is a very different animal than the feedback you're getting in this thread. It seems to me there is a lot of interest in the PSP2, the Aerco MP2, the sonosax, etc that work in stealth and low-profile situations.
And making that major decision on market will drive a lot of other decisions. Small stealth box = miniXLR connectors, minimal metering, internal battery. Larger field preamp = full-size XLR connectors, full metering, external battery, etc.
Good luck, and looking forward to what you come up with!!
Also, as an aside, I'd really like to see the 24bit SBM1-type offering -- really small, internally powered box that does 24bit A/D. Of course, if we ever get that, then it would be nice to have some more ultra small 24bit recorders with digital input other than the MT. All of that is probably outside Chris' area of expertise, but I'd still like it!