Dozens, including two which I sent to Berlin for evaluation in Neumann's anechoic chamber, where my subjective impressions were quantified, but the results were judged to be still within Neumann manufacturing tolerances (which is technically true).

On average, ca. 3-4 dB@50Hz for the worst, less for others

TLM103 does not use a K87, and also uses a transformerless chipped amplifier design with much more processing power and components than a U87 with its single active component. TLMs of all stripes tend to add electronic artifacts of a different nature than the components on the U87 sub-board do. As this is an entry-level model, I don't have much experience with it, and don't see enough of them to judge whether the K87 derivative went through the same tight bass period.

But in the other, high quality, and widely used capsule Neumann makes, the K47/49, I did not experience the degradation of low frequencies in capsules made during the period in question.

Klaus,

thanks for the Numbers, that's something.
Although Neumann specifies +/-2 dB, their lowest frequency is approx 65 Hz due anechoic chamber size limitations, so i guess -3dB @ 50 Hz is still ok for them.
Screenshot taken from the How it's made video: "https://www.youtube.com/watch?v=jCO95wBAIt0"

The graph is both telling and confusing. It shows -6dB @65Hz (yellow line, referenced to 0dB@1KhZ). If you were extending the line you would see about 8dB attenuation at 50Hz. I am not privy to the test set up, but even that much attenuation would be extreme but explained by the wording on the screen: "Measurement No, 7, Figure of Eight" (the rest I cannot read). I'd rather see a graph with only one side on, without the extra complications the acoustic and electric summing of two capsule systems present.

Because I had repeatedly heard that lack of bass, and found it odd, and because Neumann wanted to investigate my claim, the Technical Director asked me to forward samples. The two capsules I had sent in were a pre-2000 K87, and a Mid-2000. When the tests were completed, my observations were not denied, but the performances were deemed within specs (Neumann included the graphs): The bass deviated by more than 3dB between the two.

Yes, that's obviously in fig8, also clearly visible in the treble region. Unfortunately this measurement is the only one published in the video, but i found it interesting anyway.

Ah, and Method1, don't forget to change the Ef86/Pf86 switch accordingly before you switch the tube.

-Max

Guys, Max is the real deal, he's one of the good guys! If I had a tlm I would be doing this in a heartbeat. In fact a friend just bought one and I will have the chance to hear it soon.

Thanks Dan!
I keep getting emails and pm's about availanbility - guys i'm working on a new batch. Best way to express your interest is to post here, and I'll get back to you.

-Max

I can vouch for Max's microphones as well as many other of my associates. I have his MK U-47 and it absolutely second to none, period. I will be picking one of these up as well.

Do a little research and you will see for yourself. Max's circuits are no compromise. They are as close to original schematics as humanly possible, and parts manifest the same.

An original specification (to every detail) U-47 for 3k?? Yep, I'll take it when Flea is over 5k and not using original specs, nor is any other copy that I'm aware of.

Max has a stellar reputation. Be not afraid.

Thank you for the feedback. You know what? Life is about taking risks.. I think I might go ahead and do it! My 87 AI doesn't get much use anyway.. Max 2 questions: What's the best tube(cost-no-object) I can choose for this design? Also what differences I can expect in term of sounds, compared to a stock 87 AI?

Could this mod fit a U87 Clone as in cheap chinese copy. Obviously swap the capsule to an original Neumann K87. So you would just use the Body.
Cheap and cheerful U67

Thank you, Cowboy!

Solidstate,

i include a Valvo or Siemens tube, and they sound very nice.
Obviously you can't go wrong with a telefunken either.

Nikbeat,

i already offer a DIY version of the kit on the GroupDIY forum, which is made for a chinese housing, just as you suggest.

650 bucks is not much
but it´s not nothing
and you need an 1,5 k mic on top.

I know it´s an unfair comparison
but the slate vms,
which will offer a u-67 colour as well
is around the corner. At about 1k.

Considering this,
the lack of sound examples and videos
your offer sounds somehow vague.
We´re in 2014 now.

Hi Shaman,

649€ was the price from the introductory batch, which is already sold out by now.

I don't really believe in sound samples, especially comperative ones, made by the manufacturer or vendor, the agenda&bias is rather obvious.
Soon samples will pop up from the first costumers, and i think it's the better way.
The best way, of course, is to try the mic in your own studio.

They paid for it, and if they don't like it, they'll tell, unlike someone I would pay for their service to promote my product. The product is good enough to speak/sound for itself.

I'd rather not comment Slate's product, as good as it may be.

-Max

can someone please post some audio samples of this mod u87 with u67 insides. but audio comparisons of a u67 and an original u87ai, then the mod u87 with u67 insides at the same distance with someone singing. Thanks

Are you wanting something for nothing?

You get not an emulation, but essentially a real U67 for about 1/3 the price... sounds about as close to something for nothing as you're gonna get...

Well here's the difference in Max's mics and other copies which are like you say "almost there", his mics are "there". And he's not doing this to make money like others who try to get close to the real thing with a profit margin in mind. He's a DIY guy offering the best available parts for the best result with music makers in mind.

DIY is the way to get the best tools for the least amount of money. These kits and retrofit ideas that Max is doing are really special. He should be thanked for his efforts instead of being met with skepticism. Like Dan said above, Max is one of the good guys.

I'll comment. When someone can defy the laws of physics I'll be a believer. But why stop at microphones. I mean why not turn some cheap Chinese 3 way monitors into ATC 25s, right I mean the same principles apply as turning a Chinese condenser into a U47. Maybe someone can figure how to turn an Mbox into a Burl, a civic into a Ferrari, hey a frog into a prince. Why not, in this brave new digital world of make believe.

wasn't it said that cds provided perfect audio playback. I'm glad I didn't throw out my vinyl.

IO Lmk when you have more available. I'll see if I can pickup a tlm67, funny, that was one mic I couldn't sell fast enough after I bought it. like several u67 inspired mics Ive tried that were to me far less than inspirational. Now I have a u67 that's all velvety goodness.

Btw, IO what's the new price? any post introductory holiday specials lol

You n Shaman are not making much sense here... There are no laws of physics in question here. Your analogies are irrelevant. We're talking about the actual capsule with the actual circuit in the actual body. There is nothing mysterious about this particular version. All the others I'm aware of are not using anything original, probably because as a commercial finished mic, they are not allowed to. This is different because it is not a finished product, it's a kit that allows you to use existing real parts to recreate the real thing.

Edit: misunderstood your post... but still somewhat relevant to shaman's earlier post...

Reread my post, I'm not talking about IOs mod. In fact I'd like a good u67 clone to go along with my u67 which is why I'm interested in the mod. I was specifically referring to mic modeling. IO wouldn't comment on it I'm a little less diplomatic. A capsule cannot be modeled anymore than the headroom of a mic pre. all the DSP processing in the world isn't going to transform a cheap capsule and solid state electronics into a vintage M7 and vf14 anymore then it could transform a pair of KRKs into ATCs. You're entitled to your opinion, I'll stick with mine.

Not to be contradictory here but a capsule certainly can be modded with great results. A friend of mine in Nashville is very handy with the Mylar. Getting capsules of all kinds within the 3 micron (or lower) range.

BTW, for the sake of this thread, the capsule choice makes huge difference on a circuit, obviously.

Sorry... totally missed your point... been working too early and too late...

I completely agree... I think this type of emulation route is absurd from the word go... Even if they CAN effectively emulate the additive effects of a given piece of equipment, which is a tall order at best, the effect of pasting that "sound" onto an existing component's sound is where the whole model falls apart. It is a testimony to the gullibility and lack of deductive thinking of the buying public and the jaded mercenary attitude of people like Slate. Starting with a supposedly clean, flat source is a nice thought but IME there is no such thing, and those few mics that approach that ideal are not cheap.

Not sure if you're confused here but I think we're talking about "modeling", not "modding".

Ahh, your right. Should have put my reading glasses on. Sorry.

Ok so Neumann have re-issued the 47 FET.. How long till the 67 comes back on line.

I highly doubt they've thrown away the tooling, as previosly evidenced by the 80's re-issue.

They've obviously finally caved and or realised that there is a demand for these products so why not feed it? Basic economics I'd have thought?

That being said It's a might attractive option for those wanting to get in the ball park with out smashing the piggy bank.

@ MAX: How does this differ from the Inntube 87 refit?

Cheers
Wiggy

You may want more detail, but see posts 22/23.

I don't really understand this? After this mod the mics are also tube microphones right? Only with different circuits than the inner tube mod?

Sorry if that wasn't clear. The U67, be it original or cloned by Max, is a tube microhone too, of course. But it's very different from the Innertube modded U87.

As far as i know, the Innertube is not a clone of the U67 (or any other classic tube mic circuit). It's pattern switching is done remotely from the PSU via pot, it features a E88cc tube, and from what I've read, it has a very high output impedance.

My Mod employs all the features found in the original U67 - a Bv.12 transformer wound from the original blueprints, with the tertiary feeback winding and innerwinding shield, the (P)EF86 tube and the circuit with it's filter network to tame the HF emphasis of the K67 capsule.
No corners cut.

Your point is a good one and to be honest
I don't have a fully valid reply.

I think microphone companies have spent too much time
thinking into old directions. Neumann has a digital mic for
quite a while and could easily have done something a la slate vms
if they only wanted...but instead they pretended their old theme.

Is there a difference between creating a digital model of an existing
electronic circuit and recreating the very same circuit ?
This is an open question which will be adressed to all of us
in the upcoming age of 3-D printing and close to perfect plugins.

First, this is perfect for people like me who already own U87's that's aren't getting much use.

It's a hardware swap that's a U67 circuit (to match the identical capsule you already own). The only things that make it "almost there" is it's a different transformer and tube. It's an identical circuit. It's more a U67 than any of the current offerings from any manufacturer.

You then suggest a clean mic through a plugin as a better solution? I disagree there. The latency alone kills it, unless they do AAX DSP, which they said would not be likely.

Like you, I don't do "almost there", but in this case it's really cheap to make an 87 a 67. I didn't purchase because I'm not sure I won't use my U87 as a U87.

I tried to find a couple parts so I could have the best of both worlds, but no luck so far.

Same tube, actually, and might as well be the same transformer, as well.

It essentially IS a 67...