The microphone capsule photo and information thread

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Might do voice test later, have flu and sound like a malfunctioning robot right now. :)

Used the white "RK-87" capsule to replace the one in my slightly modded T.Bone SC-400 and to my ears there was great improvement, haven't yet to test the green one but i have something planned for it too.
Get healthy as soon as possible!
The sc400 capsule isn't bad, if the Ali RK87 sounds better then it can definitely be of interest. Put a link to the seller.
Thank you!
 
Both of these models should come from Takstar, an experienced "replicator" who processes metal plates in Ningbo. Their K67 series is still good, and Kingkorg has tested their CTS-2. In China, they process tens of thousands of plates at once, with colored plastic rings used to identify customersView attachment 145792
Good to know, interesting!
Great value in that case, 797 capsule(double sided) for me was triple the cost off Alibaba :)
 
Both of these models should come from Takstar, an experienced "replicator" who processes metal plates in Ningbo. Their K67 series is still good, and Kingkorg has tested their CTS-2. In China, they process tens of thousands of plates at once, with colored plastic rings used to identify customersView attachment 145792
The chart with FR belongs to @kingkorg , and I allowed myself to write on it which are the compared capsules.
Are you sure the capsules presented by @nyystero are produced by Takstar? I have doubts about this.
 

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The chart with FR belongs to @kingkorg , and I allowed myself to write on it which are the compared capsules.
Are you sure the capsules presented by @nyystero are produced by Takstar? I have doubts about this.
Of course, I was also deeply skeptical about this until they showed these pictures. In fact, there are far more styles than that. Almost all of the electrodes for Chinese capsules are made by Ningbo OEM, with the difference being whether they have undergone secondary polishing09c41b963cae587c77a51b9c9483561.jpg1930ee9245df97b8cc7e6ea2645760a.jpgdf49ea60575c8cf757153a03246454d.jpgb94ae8851c8e421d53dd646e435e101.jpga42f45061daab4d90c7f1a014c896c3.jpg
 
Of course, I was also deeply skeptical about this until they showed these pictures. In fact, there are far more styles than that. Almost all of the electrodes for Chinese capsules are made by Ningbo OEM, with the difference being whether they have undergone secondary polishingView attachment 145795View attachment 145796View attachment 145797View attachment 145798View attachment 145799
CTS-2-R-01 are only available on Taobao?
Have you tested it how does it sound?
 
Here's one I took for granted, that when the Blue Bluebird's capsule was referred to as a "B8" (at least on Recording Hacks, not sure what their source was for that) it has little to do with the "B8" established in the Bottle Cap line. Here they are side-by-side, guess which is which ;)

FWIW, this is from an SL but I also have a Chinese non-SL Bluebird whose capsule looks the same as this. Now, the early US models have a capsule that is more like the Bottle Cap version than the newer ones, but still different. That mic is basically new old stock, so not willing to take it apart given the base of these things are notoriously sticky and I've done some serious damage taking an old Latvian one apart before.

PXL_20250225_002917550.NIGHT.RAW-01.COVER.jpgPXL_20250225_003013343.RAW-01.COVER.jpg
 
Recently took possession of a Miktek PM5 (allegedly using the same capsule as their CM5 pencil condenser). Retails for a pretty penny; i landed it for a song because it doesn't work.

Pretty simple circuit, capsule "passively" biased with ~45V, single 2N3819 and an AMI transformer, kinda like a stripped-down KM84. Worst case I'll swap out the JFET...

(Later edit) Transformer primary's open. Worst case I'll wire in an 87-type transformer, tape it in good and call it a day. Circuit's quite KM84-ish without a zener, and the switchable output capacitor.
 

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fun fact about some ivory k87s
photo_2025-03-02_03-35-37.jpg
at least some k67/87 plates have 8 mount holes with custom screws to close off the ones that aren't symmetrical with the other plate. this seems to have been out of a desire to make the 4 mounting holes symmetrical on both plates. @GeorgeToledo mentioned concern about removing brass from under the active diaphragm area once. apparently neumann was also worried about this if they went out of their way to make custom screws instead of the much easier path of having 8 open holes.

What's more interesting is that this particular unit, which was untouched (and broken), has 2 entirely different plates drawings:
photo_2025-03-02_03-35-38.jpg

there are a few differences between the plates, notably that the left one doesn't have the 4 extra screw holes. intriguing. looks like they were pretty laissez-faire about mixing their plate models at this point. modern neumann capsules just have 4 holes and do not care about making them symmetrical

also in reference to my post about using american imperial being at the time (and still largely being with a few exceptions) the standard for film thickness rather than metric, this k87's center isolating spacer is 200 gauge (50.8 micron):
photo_2025-03-02_03-49-09.jpg
 
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Can you unscrew the bevelled ring on the front side to remove the brass screen and replace the diaphragm?

Jan
The front ring unscrews to remove the screen, but the diaphragm has to be removed from the back. I suggest leaving the nut in place on the center term; and just removing the rear retaining ring and pulling out the backplate assy as a unit.
 
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