Confused about capsules...

[jBam]

Hi gang,

I've studied and read enough on mic build and and capsules to come full circle - I'm confused again lol. I'm hoping someone can assist in some fundamentals...

I'm aiming to do two d-87's, wired switchable for multi-pattern.

So a k87 is basically a k67 but with isolated backplates (and I need isolated backplates for the u87 config I want, right?).

So I'm hoping to keep initial costs low... perhaps upgrade later - but things like e.g. a beezneez 87 cap are out of budget. Ideally I'll spend <USD$100/cap.

So - I'm basically having trouble working out if something is suitable unless it says "87" in the name, but I see a lot of threads reference k87 options from e.g. 797 Audio, and I don't have a clue how to confirm which has isolated backplates from their naming conventions or data? Or are people just wiring a k67 in cardioid or something for some suggestions?

Specific question: is a JLI-86U a k87 equivalent?? 4 wires suggests isolated backplates and there's a HF bump... but that's all I can get from the info on their site...

https://www.jlielectronics.com/microphone-capsules/jli-86u/
Sorry in advance! I know an easy answer is: buy RK87 from a reputable store... but hoping to shave some cost if possible... OR spend similar for higher quality...

 

[MagnetoSound]

That one looks to have isolated backplates but is also edge-terminated. The K67/87 is centre-terminated.

I can’t comment on the quality.

 

[jBam]

Ah yes of course!... *facepalm*... even I should be able to recognise these things by now... I told you I was getting confused ...

 

[soliloqueen]

real k87s with properly isolated backplates are rare, because the capsule design is "obsolete" and not used for anything but u87i clones. You've essentially got the RK87 and my capsule and that's it, in your price range. The issue is that the u87i is an inherently expensive microphone with specialty parts required to cater to its unique design. If you want to build a cheaper mic, I'd suggest doing a different circuit altogether.

I think someone here had a u87ai-esque circuit board for sale. You could use just about any third-party 3-wire k67 in that!

 

[jBam]

Thanks solioqueen ...

*double facepalm*

Trust me to drift aimlessly into the middle of the hard-basket... and here I was thinking I was trying to avoid complex things by going fet lol... all good... I mean, I'd still love a classic U87 pair of course.

I'll search around for that AI option too... might be a good solution.

How is your supply chain going? I see they've been on backorder for a while (and read through some of your woes getting suppliers to play nice). Ive heard nothing hut good thing about your caps. I've also reached out to 3U but haven't heard back yet.

 

[soliloqueen]

How is your supply chain going? I see they've been on backorder for a while (and read through some of your woes getting suppliers to play nice). Ive heard nothing hut good thing about your caps. I've also reached out to 3U but haven't heard back yet.

my k87s are actually back in stock tomorrow. I did an interim batch with the parts from v2 but the film from v1 to fulfill v1 clearance-marked orders and preorders from before the V2 announcement. After fulfilling every existing order I'll have about 12 left.

 

[jBam]

Oh wow... Ok. That might end my search then ... I'll have a (quick) think... 12 is not many lol...

 

[ElSmurf]

Oh wow... Ok. That might end my search then ... I'll have a (quick) think... 12 is not many lol...

Don't think about it, just get them. These have proven to be great K87 capsules, and I personally couldn't be happier with mine. You won't be disappointed.

 

[jBam]

Yeah... I just did ...

 

[jBam]

Actually, and just a random extra question... so that JLI-86U that I discussed in my original post... now that I've been properly looking at terminations, it's starting to look like a ck12 with isolated backplates. Any thoughts on using this in e.g. a 414c EB??... I sense another facepalm moment lol...

 

[MagnetoSound]

It’s suitable for the circuit (although isolated backplate is not needed), the only answer is try it and see. Maybe look for reviews or comments on the capsule itself before you commit.

 

[micolas]

Hi ! You have the frequency response below, maybe the capsule would be more suitable for a C800G

 

[kingkorg]

Hi ! You have the frequency response below, maybe the capsule would be more suitable for a C800G

Those capsule responses are not correct, and no, it is an edge terminated capsule, by no means suitable for c800g.

 

[micolas]

Hi Kingkorg! For what type of microphone would you use the JLI-86u capsule?

 

[kingkorg]

Hi Kingkorg! For what type of microphone would you use the JLI-86u capsule?

It is it's own thing like Røde mics are for example... Not really suitable for any historically accurate replica, but good in it's own right. It is kind of k67 with smoother high end boost and extended frequency response. Often some low end boost.

 

[micolas]

Kingkorg

I absolutely agree with you.
I am also a big fan of Rode, I have many models. Each is suitable for a scenario. But...
I was amazed by the similarity in frequency response, mid-high, treble, of the NT1a to the U87ai.
So I built a U87ai clone with more pronounced Lo-Cut, I think I put 220pF in the feedback network.
M-audio Nova body in which I stuck the NT1a capsule with glue. Bias behind the ear, under 11v. Polarization capsule 65v, it seemed to me sweet spot, a pleasant saturation of the transformer.
I went to a friend who has an acoustically treated studio and used the method you described, with pink noise, to equalize in CurveEQ (with 60 resolution) the clone after my friend's U87ai.
Although the capsules are constructively different, terminared at the edge vs in the center, etc., etc.,
my friend, a musician and sound engineer for decades, could not recognize in voice and acoustic guitar tests, which Neumann is
Of course in cardioid, on the axis. It's funny, but I've always liked breaking the rules, doing crazy experiments. I think this is where the great pleasure lies in the DIY passion.

 

[MicMaven]

... It's funny, but I've always liked breaking the rules, doing crazy experiments. I think this is where the great pleasure lies in the DIY passion.

YES. That is IT ! I agree! __ James/K8JHR

 

[Icantthinkofaname]

It is it's own thing like Røde mics are for example... Not really suitable for any historically accurate replica, but good in it's own right. It is kind of k67 with smoother high end boost and extended frequency response. Often some low end boost.

As much flak as they get from some snobs, I'm a big fan of the Rode NT2000 and other similarly voiced mics with edge terminated capsules.

 

[kingkorg]

As much flak as they get from some snobs, I'm a big fan of the Rode NT2000 and other similarly voiced mics with edge terminated capsules.

+1

The only "sin" Rødes have is higher tension of the diaphragm. This is to achieve better tolerance to plosives edge capsules are prone to, and allow for higher pol. voltage and low noise. Even then they have more low end than original k67. Solution is to add couple of db an 50hz, and you get the same performance as with looser diaphragm retaining all the positive aspects Røde capsule has.

So whatever issue snobs have in the high end is actually from couple of db they lack in the low end.

 

[ZHOUJUN]

The damping holes of many cloned versions of K87 and K67 capsule copper plates are somewhat different from the real K87 and K67 damping holes，The processing accuracy and structure are also different, and the sound should also be different.