I will have something by the end of this year.
I'd buy a kit right now that included the parts to make one of the jensen reference designs.. that mouser catalog is just too damn heavy to lift when I'm sitting on the can.
Thinking aloud here... (nice to be off the post tooth extraction vicodin!)
I think one gotcha you need to watch out for is claims of copying.. Nobody wants to be accused of that.. the trouble is, these preamps are really quite simple (except for the aerco 48v circuit, that's some special sauce!) and there are only so many ways to build them (or so it seems from my couch). You want it to be clear to everyone that this is your design and not a copy of an 148 or aerco. Of course Doug knows there is demand for the 148 that he cannot fill. Maybe he'd license the design to you and everyone would be very happy? Maybe the price could even come down (because it is very high given the contents). Seems like that would be good for everyone.
One thing about Doug.. He has insanely high end playback. So his ability to evaluate the true sonic characteristics of these designs is beyond many folks here. So perhaps the 148 price is justified from the cost and time of that r&d. I haven't owned or run one but I'm going to go out on a limb and say the 148 sound didn't happen by accident or luck..
I could post the rmod/nbox schematic here and everyone with significant assembly skills could copy it. I'll bet I could have it built in china for cheap. But would Nick, who is also a serious taper, continue to support his customers like he does? Probably not. And that support is critical. Hence, no schematic. When producing a new preamp, I think it needs to be more than "cheaper".. Undercutting the prices with a clip light also isn't enough....
As an aside.. My aerco gets gain from the op-amp and not the transformer. I know there is a version that gets 20dB from the transformer. The aerco is a very quiet preamp at any gain setting.. but when you run it at 0dB gain it is Super quiet because it bypasses most everything.. So that makes me wonder just how quiet a version that gets 20dB from the transformer could be.. But I also wonder what the sonic downsides to that are...
Sorry for getting off topic in what is pretty much our "team aerco" thread.. We had a good DIY 148 thread going.. Maybe that would be a better place to discuss the wish list and pitfalls?