The new design with the OH300 and phase comparator is ready to go. Here are some performance plots:

The little glitch you can see under the dotted red lines is a firmware bug I've already fixed, so you can ignore it.

I do have a couple more board revisions on their way from OSHPark. One is the DOT050V variant with the same phase detector addition. I wouldn't be inclined to bother with the cheaper oscillator, but they seem to sell pretty well, so I'll give it a try to see how it functions. The second is the OH300 variant. That one is getting an additional LC filter on the output of the 3.3v buck converter to see if there's any noise and ripple reduction, and if so, can we gain any low-tau stability. I'm also going to try a separate high precision regulator for the VREF and compression amp power. This flies in the face of Connor Winfield's recommendations, which are aimed at insuring that the two power rails maintain the same temperature response curve, but there's been criticism that the trim voltage is being derived from the relatively noisy supply rail. The test will be to see if there's a substantive difference between the regulator being in place and just using a wire to connect its output up to the nearby oscillator supply rail. Similarly, replacing the inductor in the supply filter with a 0Ω resistor and removing the second cap will be its performance test control.

Those ought to be here in the middle of next week. Regardless of how those tests come out, those boards will be available in the store, in whatever is the winning configuration.