Tell us how you really feel, JJNothing does what a U47 equipped with a K47 capsule, VF14 tube and BV8 transformer does. I own three of the real thing, and I've tried them all. (I'm leaving out M7 capsules, because no original M7s exist within factory tolerances, due to PVC striking and hardening.)
When Oliver Archut was alive, he was able to build variants of the BV8 that balanced the low end to work with other tubes, but it still never did that same "midrange authority" that a VF14 equipped mic gives you.
The Slate is snake oil. In a mix, it will sound close, but it doesn't do what the 47 does, and definitely not when you start using it in some of the distant applications where a 47 sounds so nice, aside from close miking technique.
And it won't give you the 47 omni experience, which is responsible for some of my favorite vocals. The sheen that adds to top end is superb.
The Neumann M147 is a POS. Avoid the M149. Overpriced IC electronic crap, with a tube stuck in for marketing purposes. The Telefunken VK14k tube is meh. It's a glass tube stuck in a can. I heard an EF14 equipped Wunder that worked OK, but lacked a little thump. The Bock 507, which not a 47 copy, is amazing. Worth trying, but not cheap. Flea is making good stuff. Worth trying out. Everything else isn't even close.
Not that it matters but the 49 seems to me like a much stronger contender to go the vintage route vs clone. I've heard a few vocals cut with 49s at considerable distances and the reach and intimacy was so outstanding that i wondered if any other mic could match it.My 47s don't get used as much as my 251s or 49s, honestly.
Editing for accuracy:Discussion about the mod is archived here:
"The original, first generation M49, as an example, never had any low end- or output attenuation, and only the tiniest amount of high end shelving. But later versions had a severe low cut, (fortunately, removable) a gain reduction of 4dB, and a clearly audible high end cut."
I'm trying to follow along but am confused about the shelving at 12KHz thing. In cardioid the frequency plot for the M49c shows a HPF with roughly a 40 Hz cut-off (-3dB) and the high freq roll off (-3 dB) at roughly 16K. Therefore the "40-16,000 cycles" spec. There's a bump at 12 KHz and at 14.5KHz it's flat again. The Neumanns I've heard and used don't sound like they are shelving a 12KHz, quite the opposite. I did mention reach before and believe it's quality lies in exactly that bump followed by roll off. Not sure if I'd want to mess with it. There are many mics with a more extended upper HF response that don't sound anywhere near as lively at a distance IMO.I don't know what he's referring to in terms of 20kHz, though. Even the original M49s start shelving at 12kHz, before that filter was put in.