China 'KM184'?

[OneRoomStudio]

Are you sure it won't fit in, @RuudNL? AFAIK, the tube diameter of the KM184 is 22mm. Assuming the Chinese made a 1:1 clone, the fake one should have the same diameter. Most, if not all 22mm SDCs, e.g. the Takstars and MXL603S, fit the BV107 clones, such as the Cinemag CM-5722, AMI or ASTDS T8 and 3U GZT-84.

Spending €250 on a single KM184 clone is a bit too much for me, but I'd love to make a PCB for it with one of my improved KM84 style circuits: One is a KM84 circuit with RFI filter and the other is the same circuit, but biased at higher current for lower noise and with CMOS boost converter for higher sensitivity. Both 90% SMT.

If anyone can share the board dimensions, I'm willing to design the board.

Jan

Just to add to this, I designed a KM84 PCB to fit into an Oktava MK-012 body (see thread here), using a Bv.107 from @Moby, and while it was tight, it did fit. The Oktava body was also 22mm IIRC.

 

[RuudNL]

As always, there is only one way to find out: try it!
The point is that apart from the transformer you also need space for the electronic circuit.
And the spring for the capsule contact takes a relative big part of the length of the PCB.
(Not to forget the XLR insert...)

 

[jp8]

As always, there is only one way to find out: try it!
The point is that apart from the transformer you also need space for the electronic circuit.
And the spring for the capsule contact takes a relative big part of the length of the PCB.
(Not to forget the XLR insert...)

SMTs to the rescue?

Just checked out the KM184 length and compared this to the CM-60, for which I designed a KM84 PCB without the CMOS oscillator. With a length of just 107mm versus 132 for the CM-60, the KM184 is pretty short, indeed. The length of the CM-60 PCB is 84mm, which I can reduce to an estimated 64...70mm, depending on how much room the capsule connection takes. I'm afraid adding the CMOS oscillator will not be feasible on such a small board, or I should use less DIY-friendly SMT elcaps and 0402 and 0603 SMTs where possible.

Jan

 

[paulcheeba]

I'm not sure a KM184 is a mic to aspire to...

I think they get a bad rep but they sound great. I personally picked the Km184 over the Km84 in all the shootouts. I like Soyuz 013 tubes and Schoeps. Beesneez Lulus sound really punchy too. There’s a place for all of them.

 

[Migs 31]

I agree with Paul:
« There’s a place for all of them.«

I used KM184 on Violins in a Symphonic Orchestra (not my first choice) but they did well. Also as drum overheads - not bad. It’s just that people compare them to their older brother (KM84) inevitably.

M

 

[Barry Hufker]

I'm afraid I did indeed compare the 184 to the 84, and also to its kin the 140. I would take the 84 any day over the others. But Neumann sells a lot of 184s, so someone is definitely enjoying them. The 184/140 frequency response is modeled after the KM54, but I find the 54 to be a much more enjoyable version than these newer models.

 

[bremusound]

The 140/184 has better rear rejection than the 84, that‘s one reason why it has its fans.

 

[kingkorg]

I'm afraid I did indeed compare the 184 to the 84, and also to its kin the 140. I would take the 84 any day over the others. But Neumann sells a lot of 184s, so someone is definitely enjoying them. The 184/140 frequency response is modeled after the KM54, but I find the 54 to be a much more enjoyable version than these newer models.

KM84 has terrible mechanical capsule stability issues. Several weak failure points, like the pins that easily get broken, or dependency on a tensioning ring for several key aspects of it's performance which gets loose over time.

These are some of the reasons they "upgraded" km84 to km184.

Up until now i had just 4 of km84 on my hands, but all 4 were severely out of spec, yet the owners swore on their sound, believing this was the way they were supposed to be.

I agree with you, but personally i would only buy, or even use km84 if i were 100% certain they are in spec.

This China km184 is not a good platform for km84 clones, because even if the capsule were good it isn't the ringt one for km84. Look how thin is the venting slot, compared to the km84.

Having in mind for how much KMS105 rip--offs go, and how well mechanically they are built, i wouldn't pay more than 50$ for these.

 

[k brown]

@kingkorg measurements of the Takstar CM-60/Pronomic SCM-1, with KM 84; Takstar in blue, KM 84 in green.

With the grille removed from the Takstar, most of the 8kHz bump is removed, bringing it very close to the Neumann.
https://groupdiy.com/threads/pronomic-scm-1.69474/page-7

Don't think I'd mess with these China 'fakes', especially given the price compared to the Takstars. Only issue is they're a bit noisy for some purposes.

 

[Paul W]

@kingkorg measurements of the Takstar CM-60/Pronomic SCM-1, with KM 84; Takstar in blue, KM 84 in green.

With the grille removed from the Takstar, most of the 8kHz bump is removed, bringing it very close to the Neumann.
https://groupdiy.com/threads/pronomic-scm-1.69474/page-7

Some of KingKorg's comments on that graph, worth repeating (especially the part about KM84's weaker bass response apparently being due to being further from the speaker, i.e., not real):

Blue line is old style Pronomic, MXL, Subzero type capsules...
Red one is Shayin cardioid capsule
Yellow is Shayin hypercardioid capsule
Green is Neumann KM84, but you can omit weaker bass response, it's older measuerment and i believe KM84 was furthet away from the speaker. However the curve is pretty mush identical, it's just amplitude difference.

So yes i dare to say KM84 and these new capsules are almost as matched pair, if you omit proximity effect with km84 here.

I'm not sure what "old style" means here. Do current Takstars have the old style capsule?

 

[k brown]

Some of KingKorg's comments on that graph, worth repeating (especially the part about KM84's weaker bass response apparently being due to being further from the speaker, i.e., not real):



I'm not sure what "old style" means here. Do current Takstars have the old style capsule?

He was referring the the style of grille on the front of the capsules. The thread that was in was mostly about a multi-hole style grille that was briefly on the SCM-1 capsules; they have gone back to the slotted style now found on the Takstars (the "old style"), that's shown on the graph. The 8kHz peak is from the deep recess of the diaphrams on both styles, and not form the style of grille.

Except for the grille style, all have the same capsule design.

 

[Whoops]

which company?

https://www.aliexpress.com/item/100...AmDVsWGg&utparam-url=scene:search|query_from:

 

[RuudNL]

Keep in mind that the electronics are very noisy!
But I tested the capsule on a different body and to my ears they sounded not too bad.

 

[Whoops]

Keep in mind that the electronics are very noisy!

Hi Ruud, thank you so much for sharing your findings about this unit.

Why do you think the electronics are noisy?
Is it because they used a completely different circuit than the KM184 or because of the components they choose?

I'm asking this because the U87ai china knockoff as far as I know uses the same exact circuit as the original U87ai and I don't notice any increase in noise compared to an original unit, and it actually sounds really good.

Maybe in this knock off they didn't copied the original circuit and used another electronic circuit?

 

[ccaudle]

https://www.aliexpress.com/item/1005007430036292.html?spm=a2g0o.productlist.main.5.38541e6fwaPpkK&algo_pvid=44643866-8157-44ce-9e27-495efec0b276&algo_exp_id=44643866-8157-44ce-9e27-495efec0b276-2&pdp_npi=4@dis!EUR!2532.25!354.51!!!19434.00!2720.76!@2103868d17261064389724985ed6d7!12000040725185424!sea!PT!757814645!X&curPageLogUid=RtZfAmDVsWGg&utparam-url=scene:search|query_from:

Bold, they even have a zoomed in picture showing the "Made in Germany" label. Deutch customs officials might raise an eyebrow at "Made in Germany" goods being imported from AliExpress.

 

[RuudNL]

@Whoops : If you compare the pictures of the PCBs in post #6 (Neumann and 'China') I don't see any difference.
But maybe they used other (or inferior) components. Anyway: The 'Chinese' KM184's are not usable for serious recordings. Way too noisy! Which is a pity, because from what I heard the capsules are pretty good.

 

[jp8]

A missed opportunity. It should not be that hard to build a half-decent low-noise head amp and generate more sales. Yet another example of what I consider irrational product engineering that is soooo typical for many chinese products. They are going to great lengths to exactly copy a product, then forget to use quality components...

Same story for the KMS105 clone with 22mm capsule. Decent capsule but horribly noisy.

https://groupdiy.com/threads/new-22mm-km184-kk105-style-capsule.84519/post-1167726

Jan

 

[Whoops]

Bold, they even have a zoomed in picture showing the "Made in Germany" label. Deutch customs officials might raise an eyebrow at "Made in Germany" goods being imported from AliExpress.

These Chinese Neumann branded microphones have been entering Germany and EU with no problems at all for somes years now, I talk from first hand experience.
normally the outside box does't have the Neumann logo or "Made in Germany" just the insides.

You also have China Shure, China Sennheiser, China Gibson...

 

[Whoops]

@Whoops : If you compare the pictures of the PCBs in post #6 (Neumann and 'China') I don't see any difference.

Yes, looking at it they seem to be the same exact circuit

But maybe they used other (or inferior) components. Anyway: The 'Chinese' KM184's are not usable for serious recordings. Way too noisy! Which is a pity, because from what I heard the capsules are pretty good.

Being that the circuits are the same then it shouldn't be to difficult to find the reason for the extra added noise, it could only be due to the use of some inferior components at some points, probably the semiconductors.
I bet we can easily find the culprit components (noise), if the circuits are the same then they can sound the same

It's smd which is a little harder to swap stuff and test but totally feasibly.

The hard part would be if the capsule was not good, but if the capsule is decent then the electronic circuit is the easy link in the chain

 

[Whoops]

A missed opportunity. It should not be that hard to build a half-decent low-noise head amp and generate more sales. Yet another example of what I consider irrational product engineering that is soooo typical for many chinese products. They are going to great lengths to exactly copy a product, then forget to use quality components...

That's not what they did with their U87ai, that one sounds great just out of the box.
You can take it out of the box and use it in a professional recording session.

although all of these are faked Neumanns it seems that probably the original "cloner" developer of them was not the same person/company in these different models