I have experience with this unit, both as someone who has sold them and received customer feedback, and as someone who has used them in numerous recording situations, primarily for on-location classical and jazz sessions. I’m not quite sure why these units don’t get a tremendous amount of love, other than the fact that they remain fairly unknown, but they are really quite impressive.
I found that they add that subtle element of musicality and forgiveness to what can sometimes be the unforgivingly truthful sound of a traditional Millennia HV-series mic pre. A good comparison would be DPA mics: as good as they are, sometimes the truth that they reveal can be a little too much- it’s honestly probably why people often prefer Schoeps over DPA’s. However, what this unit does, while similar to the Schoeps/DPA comparison in terms of musicality and forgiveness, is quite different. It really adds a gorgeous three-dimensional splash of tube texture in a very subtle and unimposing way, without the traditional sacrifices you have to pay when adding tubes to extremely delicate and detailed acoustic recordings. Every time I used it with a pair of small diaphragm condensers, I found that they benefited from the subtle but unimposing warmth that the unit delivered. This is not a tube unit that has a very in-your-face coloration about it, but rather one that can add some real subtle, harmonic activity without a major sacrifice on the detail side of things.
If you are looking for something with its own more personalized tube character and lots of tube warmth, but that still retains excellent detail, think Fearn VT-2, or at less of a budget, perhaps the Anthony Demaria ADL600 (manufactured by Presonus). However, if you are looking for primarily extreme Millennia-like detail with only a mere splash of tube harmonics to warm things up, then this is a really nice choice.
I loved the way this unit interacted with both Schoeps CMC6/MK4’s and MK21’s and with DPA 4011’s and 4006’s, but also with some large diaphragm microphones that ordinarily I never would have thought could have worked on a location situation through a tube unit, because I would have anticipated the combination to be too muddy. I loved the way the Neumann TLM193’s sounded through it.
All this being said, to this point, most of the people using the M-2B (at least the ones to whom we have sold it and to whom we’ve talked about it), from my experience, are location guys, not studio guys. There’s no obvious reason for this, other than that that’s the way it has been consumed. Perhaps it’s the fact that it’s Millennia, and for a lot of location engineers, that’s where it starts and stops. Clearly, there’s a lot of good reasons to put one of these in a serious studio environment as well. In fact, in a lot of ways, it makes more sense to own one of these than an HV3 for many studios, in my opinion, and yet I wouldn’t be surprised if the HV’s sell at a ratio of 100 channels to 1 over the M-2B. I'm pretty sure this preamp will surprise you. -Todd