Kookie's Blue Kiwi repair thread

[micolas]

The female 4 pin connector is embedded within the top endcap that doubles as a headbasket mount. It's in there quite tight, so I suspect it it's hammered in place at the factory, I'd rather avoid breaking it if I can do a non destructive test first.

I have more detail on the big specialist. I won't share their name because I don't want to impact their business or anything of the sort. I will just say they only advertise their work on Neumann microphones, and the U47 clones they manufacture. It seems like a trademark of their work is systematically upgrading the components in all mics that go through their shop.
I guess that's what happened here, they swapped the caps and resistors for more boutique ones, but still were not able to fix the mic. I was a little surprised at the scratch-marks and excess flux, but given what I've read that's the work of someone with 15 years of experience. So I'll approach it with respect.

OK. This is not about that specialist. Let's forget about him.Many of us here have decades of experience and we still do stupid things, but we must always have respect for our customers.
*
Identifies capsule wire connections to connector with DMM.
Between the pins of the connector and the screws of the diaphragms and the backplate.
Or measure directly on the capsule screws if there is a short circuit between the diaphragm(s) and the backplate.

 

[Khron]

given what I've read that's the work of someone with 15 years of experience. So I'll approach it with respect.

Just because one does something for a long time, doesn't automatically / necessarily mean they get any better at it than when they first started. Why not evaluate the quality of one's work by the results, as opposed to their history? It's really counter-intuitive to me... Especially since, despite the "15 years of experience" (doing what, i wonder? and apparently learning nothing from it),

still were not able to fix the mic

Not sure years of experience blindly swapping components out really counts for anything, but that's just me. And not calling out BS when one sees it, just helps perpetuate myths, hyperbole and questionable business practices, especially in this field of audio... Makes you wonder how many other clients' microphones they mangled, and still charged them whatever pretty penny their going rates are...

 

[micolas]

Just because one does something for a long time, doesn't automatically / necessarily mean they get any better at it than when they first started. Why not evaluate the quality of one's work by the results, as opposed to their history? It's really counter-intuitive to me... Especially since, despite the "15 years of experience" (doing what, i wonder? and apparently learning nothing from it),



Not sure years of experience blindly swapping components out really counts for anything, but that's just me. And not calling out BS when one sees it, just helps perpetuate myths, hyperbole and questionable business practices, especially in this field of audio... Makes you wonder how many other clients' microphones they mangled, and still charged them whatever pretty penny their going rates are...

+1
I couldn't have described things better.

 

[SoundsOfJill]

OK. This is not about that specialist. Let's forget about him.Many of us here have decades of experience and we still do stupid things, but we must always have respect for our customers.
*
Identifies capsule wire connections to connector with DMM.
Between the pins of the connector and the screws of the diaphragms and the backplate.
Or measure directly on the capsule screws if there is a short circuit between the diaphragm(s) and the backplate.

No shorts that I could measure. Both diaphragms and the backplates have connections to the 4 pin connector.

I gave the capsule a more careful inspection , it looks like it's covered in superglue? the membrane doesn't seem to have any on it though. I think you can see it on the pictures I put up earlier on the threads. Also two of the four coupling screws for the capsule seem to be missing. The might just be the capsule's design, but I find it weird.

I'm still on a quest for a long enough hex wrench to be able to get the PCB out.

 

[SoundsOfJill]

Just because one does something for a long time, doesn't automatically / necessarily mean they get any better at it than when they first started. Why not evaluate the quality of one's work by the results, as opposed to their history? It's really counter-intuitive to me... Especially since, despite the "15 years of experience" (doing what, i wonder? and apparently learning nothing from it),



Not sure years of experience blindly swapping components out really counts for anything, but that's just me. And not calling out BS when one sees it, just helps perpetuate myths, hyperbole and questionable business practices, especially in this field of audio... Makes you wonder how many other clients' microphones they mangled, and still charged them whatever pretty penny their going rates are...

I'm just being cautious because I realize the repair person in question could be a member of this forum. Given that they make U-47 clones, they could also be one of soliloqueen's clients.

So before I call anything out I wanna make 100% sure that there is indeed some form of malpractice.

 

[micolas]

I'm just being cautious because I realize the repair person in question could be a member of this forum. Given that they make U-47 clones, they could also be one of soliloqueen's clients.

So before I call anything out I wanna make 100% sure that there is indeed some form of malpractice.

Yes, I agree with you.
We must always treat all people with respect.

 

[micolas]

I gave the capsule a more careful inspection , it looks like it's covered in superglue?

I thought I saw a strange sheen on the capsule.
Superglue? Kinda weird...

 

[SoundsOfJill]

I thought I saw a strange sheen on the capsule.
Superglue? Kinda weird...

I touched it and I don't have any oily residue on my fingers. If not superglue I'd wager it's some kind of adhesive

 

[Khron]

I'm just being cautious because I realize the repair person in question could be a member of this forum. Given that they make U-47 clones, they could also be one of soliloqueen's clients.

So before I call anything out I wanna make 100% sure that there is indeed some form of malpractice.

Manufacturing (?) things is one thing; servicing is totally different, i hope you'll agree. Even if they were a member here, or a client of another, don't people deserve to know? And if they weren't able to at least troubleshoot, nevermind repair, such a(n arguably trivial) microphone / circuit, what does that say about their skills / determination / resourcefulness, nevermind experience? And it's sort of implied you'd rather have others risk having their property remain useless (or worse, getting damaged), than possibly damaging someone's side-hustle?

A quick google search for "blue kiwi schematic" brought up a thread here from 12 years ago, with beautiful photos of both sides of the board.

https://groupdiy.com/threads/blue-microphones-kiwi-pcb.52278/

Reverse-engineering that couldn't take more than a couple hours (especially with the board in hand). And even if the capsule was a suspect, surely wiring another one in, even temporarily for a test, would've been once again, trivial. Especially for someone who apparently PRODUCES microphones

 

[micolas]

The plot thickens

I touched it and I don't have any oily residue on my fingers. If not superglue I'd wager it's some kind of adhesive

 

[SoundsOfJill]

Manufacturing (?) things is one thing; servicing is totally different, i hope you'll agree. Even if they were a member here, or a client of another, don't people deserve to know? And if they weren't able to at least troubleshoot, nevermind repair, such a(n arguably trivial) microphone / circuit, what does that say about their skills / determination / resourcefulness, nevermind experience? And it's sort of implied you'd rather have others risk having their property remain useless (or worse, getting damaged), than possibly damaging someone's side-hustle?

A quick google search for "blue kiwi schematic" brought up a thread here from 12 years ago, with beautiful photos of both sides of the board.

https://groupdiy.com/threads/blue-microphones-kiwi-pcb.52278/

Reverse-engineering that couldn't take more than a couple hours (especially with the board in hand). And even if the capsule was a suspect, surely wiring another one in, even temporarily for a test, would've been once again, trivial. Especially for someone who apparently PRODUCES microphones

I'm not saying I don't want to call out bad repairs. I just want to make absolutely sure they're bad repairs before I do. I've been updating the previous owner ever since I received the mic. They clearly loved it when it was still functioning, so if it turns out they got scammed I will absolutely tell them.

 

[SubSpec]

Pretty sure that's conformal coating on the ring, and that's likely from the factory. Have seen it on a few Blue capsules, especially those using their floating mount. Typically it's been less heavy handed and much more even, but regardless I don't think it's likely related to the problem.

 

[SoundsOfJill]

Pretty sure that's conformal coating on the ring, and that's likely from the factory. Have seen it on a few Blue capsules, especially those using their floating mount. Typically it's been less heavy handed and much more even, but regardless I don't think it's likely related to the problem.

thanks for your input.
I guess I'll know more once I get the PCB out.

 

[Khron]

After leaving my capsule assemble in silica and near heat overnight I put it back on the mic aaaaand:
"KSHHHHHHHHHHHHHHHHHHH"

Got a 47-100pF capacitor or two, that you can solder to the appropriate pads on the board? To "emulate" the capsule, and see if the noise is due to the capsule or the circuit... I'm thinking that might be more likely than having a spare capsule...

 

[SoundsOfJill]

Got a 47-100pF capacitor or two, that you can solder to the appropriate pads on the board? To "emulate" the capsule, and see if the noise is due to the capsule or the circuit... I'm thinking that might be more likely than having a spare capsule...

I might have stuff in that range somewhere.
To be clear you want me to put those between the diaphragm and the backplate connectors on the pcb, then connect the mic to an interface and check for noise?

 

[Khron]

I might have stuff in that range somewhere.
To be clear you want me to put those between the diaphragm and the backplate connectors on the pcb, then connect the mic to an interface and check for noise?

Yep. Ideally with the mic body as complete as feasible, to minimize the mains effects (and other EMI/RFI) - we want the mic body to be as good a Faraday cage as feasible.

 

[soliloqueen]

No shorts that I could measure. Both diaphragms and the backplates have connections to the 4 pin connector.

I gave the capsule a more careful inspection , it looks like it's covered in superglue? the membrane doesn't seem to have any on it though. I think you can see it on the pictures I put up earlier on the threads. Also two of the four coupling screws for the capsule seem to be missing. The might just be the capsule's design, but I find it weird.

I'm still on a quest for a long enough hex wrench to be able to get the PCB out.

That's the conformal coating on the screws to keep it from being able to accumulate dust that might cause it to short out. That's common

 

[SoundsOfJill]

Yep. Ideally with the mic body as complete as feasible, to minimize the mains effects (and other EMI/RFI) - we want the mic body to be as good a Faraday cage as feasible.

that's gonna be tough, since the endcap and the capsule mount are the same part, it can't be put back on without connecting the capsule.
Could I get away with aluminum foil?

 

[Khron]

that's gonna be tough, since the endcap and the capsule mount are the same part, it can't be put back on without connecting the capsule.
Could I get away with aluminum foil?

If you can manage to tack some on, WITHOUT it touching any of the pins...