Without doubt one of my favourite boards on here. Interested to hear a rundown of how you use each of those dirt pedals. I have the M80 and B3K on my board also but have been interested in both the Vintage Microtubes and BB Preamp to see if they'd add something a little different.
Well, thank you! I'm really happy by now, and seriously hope it'll stay that way for a long time. About the pedals: I have a use for each one (maybe only the Blowtorch was more difficult to me to get along, but is a neat pedal if you want synthy fuzz, though). It sounds pretty obvious, but I mean I'm not only using them separately; instead, I really like stacking them.
Anyway, all four (including the distortion channel on the M80) cover a different ground:
(Signal goes: bass >> RC >> MultiComp >> BB >> VMT >> B3K >> Mooer chorus >> M80 (direct out >> Pitchblack >> amp 2, if there's any) >> amp 1.)
VMT: definitively a great pedal. I love its versatility, its grain, and how it emphasizes low mids. Incredibly good at keeping the low end; seriously, unparalleled. I tend to use it on both of the extremes it can get: really dirty tones, with the ERA knob towards clockwise; or mellow, darker tones, just to warm up a little my signal. I use it more this way, to achieve some kind of a vintage vibe (think about R. DeLeo's tone on those slower STP's songs). The blend here is magic. Just as with the B3K, it's not like you got two different signals running together; it truly blends the wet and dry portions of the signal. I can perfectly imagine someone choosing this one as an all-in-one type of drive. I like to think of the VMT as a complement of the B3K in terms of the ground each one covers. And the ERA knob is magic too. At first it seems a bit too subtle, but as you get used to it, it opens up to your ears and you note all the differences at diverse settings. You sure heard this before: it's just not a simple tone control. It' a fantastic feature and sets this pedal apart.
BB Preamp: I just got this one. So far, I only regret not doing it years ago. What a great box it is. I've come to think that Xotic pedals are almost impossible to defeat. I mean, the quality of the construction and the sounds are unbeatable. A few years back, when I got the RC, I was so impressed with these features. I know Xotic pedals have been out there for a good amount of time, but here, in Chile, getting some quality gear at a semi-reasonable price —specially for bass- is something we've recently come to know; and we're getting a little late to the pedal trends (probably you notice that when you saw the MultiComp, haha). Anyway, I just got the BB, so I can't give you a full review (it's not like I'm doing that with the others, but you get the idea), but I can surely say it is different —in a good way- from the rest of the pedals I have, and has its own sounds. Great versatility and functionality, you can go from almost totally clean to full on overdrive. Lots of bass, treble and mids to it, and great EQ. Very touch-responsive. I've always wanted to have a Fulltone BassDrive, and the BB certainly gets me in that territory. So far, I dig the compression and sustain it gives, and have always loved the mid hump you get with tubescreamers. I use this pedal to the more agressive tones.
B3K: I got this before all the other pedals you see there, back then when I got a bunch of other boxes that I already sold, so I can say I kinda know very well how the thing works. It's by far my favorite dirt pedal, and maybe my favorite pedal at all. The first time I heard it a few years back ago (can't believe it has been four years since that by now), I knew that was the tone I was looking for. I got it in mid-2012 (#49 of the first USA batch) and since that I like playing bass more than ever. It lets me get the sound I was looking for since I had 15, playing it alone, by itself, or stacking other drives into it. Well, you already have the thing, so probably not hearing anything new here. The main tone that always has inspired me is Billy Gould's ("both", the brighter and the grittier ones), and this little box has allowed me to get in that ballpark in a way absolutely no other pedal could before (and now Billy's using Darkglass… what do you know!). The B3K to me is way more than a simple overdrive/distortion; it's really a preamp, a tone shaper. That's why I keep it at the end of the chain (before chorus an DI), so I can feed it with the other drives, and give those the character the B3K has (that depth and tight sound). Like with the VMT, blend works incredibly well and feels "right". And, again, like with the VMT, all the settings are useable in real contexts; even the extreme ones. That's not a thing you got everyday. In fact, I couln't think of any other dirt boxes that has completely useable setting through their whole range. I use it almost all the time, as my fundamental tone, and also for shaping other dirt boxes.
Now, the most interesting thing to me has been experimenting with different dirt configurations. Since every one of the three has its own sound, I find it is worth to keep all of these in my board. The way I see it, each one covers a different range of frequencies; in particular, mid frequencies. In general terms, as the B3K takes care of the hi-mids, the VMT does its own with the lo-mids, and the BB focuses in the mid-mids (I don't know if it makes sense). So, when you feed one pedal into another, you can achieve a complex sound, with interesting textures. Then, for example, I can push some great mids with the BB trough the B3K, adding depth and tightning the tone at the same time. I have'em in that particular order (BB >> VMT >> B3K) mainly for two reasons:
1) Like I said, I find the B3K, besides a great overdrive/dist pedal, is an outstanding tone shaper; so I want it to go at last, imparting its sonic qualities to the whole signal chain;
2) Although I think none of these pedals *need* the clean blend by its own (they all retain in a very good way the lows), this feature has in fact an interesting role when stacking different dirts. Like in my case, I love the B3K's character, but also want to retain the original tone of the VMT or the BB, and that's when the blend knob comes handy, because you can have both drive characters at the same time. For example, I use the B3K with the blend at 50% (noon); that way, I have the best of both worlds: the cutting mids of the VMT/BB Preamp, and the tight low end and articulated hi-mids and highs of the B3K.
The distortion channel on the M80 seems very useful to me. In fact, I enjoy switching it on for a more over the top dirt. Many people dislike the fact that the dist channel activates automatically the "color", but, even if I don't like it very much for the clean channel, I think it's a well thought-out feature, as the wet portion of the signal seems to sit over the "smiley" EQ of the clean portion, letting both to mix more efectively. I think that if the clean signal in the dirt side had more mids, it'll make the whole dist channel very honky and more artificial sounding (though this is already a characteristic of the drive). Anyway, I dig it. It's just that I prefer the other dirt pedals I have, and the distortion in the M80 doesn't react well to other dirts (at least in my case).
TO SUM UP: All of the three have different flavors. Though is truth you can partially cope some similar sounds between them, there are plenty distinctive tones to justify keeping the three. But, well, I kinda like the dirt pedals much more than anything else, so… I intuit it is the same with you, doesn't it? I use'em with an L2K and a J-Bass, and the three work well with passive and active basses, and high and low output instruments (but, ovbiously, all these options change the way the dirts react).
I have the feeling I've written too much, but said a very little. I apologize if reading this doesn't help you in the end, but, please, ask me whatever you want and I promise I'll try to be more helpful.
Cheers and good luck with your decision (let me know what pedal(s) you take in the end).