Don't get me wrong, it is not THAT noticeable. They still sound like the same pedal, but I definitely notice one is a little fatter, and smoother. I mostly notice this when used as a booster (gain at 0, level about 1 oclock, EQ to taste....). You can dial them in similar once you start using them for gain. I notice either of them bringing in the more raspy midrange when the gain is brought up a little. So, instead of having gain on 0, bring it up a notch to 8 oclock or so. That seems to make it seem more like a Tubescreamer boost. This makes sense to me, because usually a Tubescreamer has a 33K, 47K, or 51K resistor in series with the gain pot, and the BB Preamp has a 10K, so it makes sense that a little more resistance would kick in that circuit more. I actually ordered a whole bunch of 1/8W resistors that will be here this weekend. Looking forward to seeing what I can do with this thing, lol. I haven't read anything about circuit difference between the paints. If anything, I thought the older paint versions were older versions, and they were updated. Maybe the companies are just using old stock photos? Mine are the same, paint-wise. I got them from the same place, just a few months apart. I actually couldn't sleep the other night, and took both apart. I didn't do any kind of in depth analysis or anything, but I just kind of compared values and such. Both appear to have the same values for parts, at least for the major parts. Some of them did look different, like different brands of caps or whatever for 1 or 2 of them. The better sounding one has cleaner soldering, so maybe there is a bad connection in the other one? Who knows. Nothing drastic stood out to me, so I can only assume it comes down to component tolerance, and cleaner soldering.