All right, I took apart a v2.01 (serial ~221000, December 2021) and the preliminary findings are as follows: Mike is, once again, either a liar or an idiot (I would lean toward liar).
So far the only difference I can see is that there are two SMD LEDs (red waterclear) labeled D6 and D7:
These are in an anti-parallel configuration and are connected to the outer pins of the Drive pot (pin 1 and pins 2/3), which means they're TS-style opamp feedback clipping, the only difference being that they are inside of the 18k minimum-gain resistor instead of directly between the opamp's output and inverting input as usual. The purpose seems to be to prevent the opamp from going into clipping at high gain settings. Maybe this impacts the bass, I don't know, but certainly it's not "tuned" in any way that is selective of bass frequencies like a capacitor would be.
This would both confirm & clarify the photo posted in
another thread. I looked at a bunch of Reverb photos and it appears that there was a span of just a few thousand with the LEDs soldered on like this, around serial 215000 to 219000. (In that photo you can't tell from the angle, but I've seen a few others where it's more clear that there is a 2nd LED underneath the first one in the hot glue.) Earlier ones don't have these LEDs on the back, and later ones don't either, so my best guess is just that there was a shortage of the SMD LEDs for a few months.
I haven't done a full trace yet, but I don't see any new capacitors at all, and certainly none near the clipping section. C4 (the one in parallel with the clipping diodes) is 4n7. The tone cap is back up to the v1 value of 47n (earlier V2s had 22n here). The opamp highpass capacitor is still 100n as in other V2s, but the series resistor is back down to 2k2 (it was 3k3 in both PPCB's and my trace of V2 units). There are some changes to the input buffer, dropping the bypass capacitor on the source, though I haven't spent much time looking at this section of the PCB yet.
So why the BS? Mike likes to spread misinformation, and I was suspicious when he said he "found a way to isolate the clipping via a smaller separate pair of caps" (
viewtopic.php?p=293561#p293561). If it was connected in the obvious way (cap in series with diodes, which should theoretically only make them clip the higher frequencies depending on the capacitor value) then you wouldn't need two capacitors unless you were an idiot, since the clipping diodes share the same audio path. You could use a single cap before the clipping diodes or after, but it's the same either way.
Unless... you were originally typing out something true and then decided to change one word at the last minute to avoid giving something away - in other words, he really meant "pair of diodes" but decided to say "pair of caps" instead. That's the best I can do to make sense of it.